diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index cec6a3234..4865840e5 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,10 +1,20 @@
 image: covenantsql/build
 
+stages:
+  - build
+  - test
+  - cleanup
+
 variables:
   REVIEWDOG_VERSION: 0.9.11
   REVIEWDOG_GITLAB_API_TOKEN: $REVIEWDOG_TOKEN
   CODECOV_TOKEN: $CODECOV_TOKEN
   UNITTESTTAGS: linux sqlite_omit_load_extension
+  CACHE_DIR: /CovenantSQL_bins
+  PIPELINE_CACHE: $CACHE_DIR/$CI_PIPELINE_IID
+  BIN_CACHE: $CACHE_DIR/$CI_PIPELINE_IID/bin
+  PREV_VERSION: v0.4.0
+  # gitlabci bins: 192.168.2.100:/srv/gitlab-runner/config/CovenantSQL_bins
 
 before_script:
   # Setup dependency management tool
@@ -23,12 +33,23 @@ before_script:
   - ulimit -n 8192
 #  - curl -fSL https://github.com/haya14busa/reviewdog/releases/download/$REVIEWDOG_VERSION/reviewdog_linux_amd64 -o ~/bin/reviewdog && chmod +x ~/bin/reviewdog
 
-test-my-project:
+build:
+  stage: build
+  script:
+    - set -x
+    - make clean
+    - make use_all_cores
+    - mkdir -p ${BIN_CACHE}
+    - cp bin/* ${BIN_CACHE}/
+
+unit-test:
   stage: test
   script: 
+    - make clean
+    - cp ${BIN_CACHE}/* bin/
     - ./alltest.sh
 
-compatibility-testnet:
+testnet-compatibility:
   stage: test
   script:
     - set -o errexit
@@ -37,7 +58,43 @@ compatibility-testnet:
     - branch=$(git branch -rv |grep $commit | awk '{print $1}')
     - if [[ $branch =~ "/beta_" ]]; then exit 0; fi
     - make clean
-    - make -j8 client
+    - cp ${BIN_CACHE}/* bin/
     - go test -tags "$UNITTESTTAGS" -bench=^BenchmarkTestnetMiner2$ -benchtime=5s -run ^$ ./cmd/cql-minerd/
     - set -x
     - ./test/testnet_client/run.sh
+
+old-client-compatibility:
+  stage: test
+  script:
+    - set -o errexit
+    - set -o pipefail
+    - set -x
+    - make clean
+    - cp ${BIN_CACHE}/* bin/
+    - ./test/compatibility/specific_old.sh client
+
+old-bp-compatibility:
+  stage: test
+  script:
+    - set -o errexit
+    - set -o pipefail
+    - set -x
+    - make clean
+    - cp ${BIN_CACHE}/* bin/
+    - ./test/compatibility/specific_old.sh bp
+
+old-miner-compatibility:
+  stage: test
+  script:
+    - set -o errexit
+    - set -o pipefail
+    - set -x
+    - make clean
+    - cp ${BIN_CACHE}/* bin/
+    - ./test/compatibility/specific_old.sh miner
+
+cleanup_cache:
+  stage: cleanup
+  script:
+    - rm -r ${PIPELINE_CACHE}
+  when: on_success
diff --git a/.travis.yml b/.travis.yml
index 23f022dff..23da32731 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -7,7 +7,7 @@ env:
     - REVIEWDOG_VERSION=0.9.11
 language: go
 go:
-  - '1.10.x'
+  - '1.11.x'
 
 os:
   - linux
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 73544d80c..5795be024 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,30 @@
 # Changelog
 
+## [v0.4.0](https://github.com/CovenantSQL/CovenantSQL/tree/v0.4.0) (2019-02-25)
+
+[Full Changelog](https://github.com/CovenantSQL/CovenantSQL/compare/v0.3.0...v0.4.0)
+
+**Merged pull requests:**
+
+- Use minimum assertion instead of exact version [\#265](https://github.com/CovenantSQL/CovenantSQL/pull/265) ([leventeliu](https://github.com/leventeliu))
+- Promote beta branch [\#264](https://github.com/CovenantSQL/CovenantSQL/pull/264) ([leventeliu](https://github.com/leventeliu))
+- Add imports format script and format all codes [\#263](https://github.com/CovenantSQL/CovenantSQL/pull/263) ([leventeliu](https://github.com/leventeliu))
+- Add listen flag for adapter [\#262](https://github.com/CovenantSQL/CovenantSQL/pull/262) ([auxten](https://github.com/auxten))
+- Use rpc broadcast for dht node info synchronization instead of kayak [\#261](https://github.com/CovenantSQL/CovenantSQL/pull/261) ([xq262144](https://github.com/xq262144))
+- Merge observer and explorer into cql [\#260](https://github.com/CovenantSQL/CovenantSQL/pull/260) ([auxten](https://github.com/auxten))
+-  Add transaction hash as return value in create/drop [\#259](https://github.com/CovenantSQL/CovenantSQL/pull/259) ([leventeliu](https://github.com/leventeliu))
+- Combine createRandomBlock functions into one. [\#258](https://github.com/CovenantSQL/CovenantSQL/pull/258) ([laodouya](https://github.com/laodouya))
+- Improve unit test cover ratio [\#257](https://github.com/CovenantSQL/CovenantSQL/pull/257) ([laodouya](https://github.com/laodouya))
+- Refactor observer synchronization to pull mode [\#256](https://github.com/CovenantSQL/CovenantSQL/pull/256) ([xq262144](https://github.com/xq262144))
+- Refactor observer synchronization to pull mode [\#255](https://github.com/CovenantSQL/CovenantSQL/pull/255) ([xq262144](https://github.com/xq262144))
+- Fix SQLChain forks [\#254](https://github.com/CovenantSQL/CovenantSQL/pull/254) ([xq262144](https://github.com/xq262144))
+- Update beta with develop updates [\#253](https://github.com/CovenantSQL/CovenantSQL/pull/253) ([xq262144](https://github.com/xq262144))
+- Improve unit test cover ratio. [\#251](https://github.com/CovenantSQL/CovenantSQL/pull/251) ([laodouya](https://github.com/laodouya))
+- Add blocks cache limit for block producers [\#249](https://github.com/CovenantSQL/CovenantSQL/pull/249) ([leventeliu](https://github.com/leventeliu))
+- Support pprof http handler in BlockProducer [\#248](https://github.com/CovenantSQL/CovenantSQL/pull/248) ([xq262144](https://github.com/xq262144))
+- Unit all docker client config to same private.key [\#247](https://github.com/CovenantSQL/CovenantSQL/pull/247) ([laodouya](https://github.com/laodouya))
+- Make observer API writeTimeout = 10 \* readTimeout [\#246](https://github.com/CovenantSQL/CovenantSQL/pull/246) ([auxten](https://github.com/auxten))
+
 ## [v0.3.0](https://github.com/CovenantSQL/CovenantSQL/tree/v0.3.0) (2019-01-30)
 
 [Full Changelog](https://github.com/CovenantSQL/CovenantSQL/compare/v0.2.0...v0.3.0)
diff --git a/Makefile b/Makefile
index e1bf36bce..ca3362038 100644
--- a/Makefile
+++ b/Makefile
@@ -17,7 +17,6 @@ use_all_cores:
 
 BUILDER := covenantsql/covenantsql-builder
 IMAGE := covenantsql/covenantsql
-OB_IMAGE := covenantsql/covenantsql-observer
 
 GIT_COMMIT ?= $(shell git rev-parse --short HEAD)
 GIT_DIRTY ?= $(shell test -n "`git status --porcelain`" && echo "+CHANGES" || true)
@@ -41,7 +40,7 @@ builder: status
 		-f docker/builder.Dockerfile \
 		.
 
-runner: builder
+docker: builder
 	docker build \
 		--tag $(IMAGE):$(VERSION) \
 		--tag $(IMAGE):latest \
@@ -50,24 +49,11 @@ runner: builder
 		-f docker/Dockerfile \
 		.
 
-observer_docker: builder
-	docker build \
-		--tag $(OB_IMAGE):$(VERSION) \
-		--tag $(OB_IMAGE):latest \
-		--build-arg COMMIT=$(COMMIT) \
-		--build-arg VERSION=$(VERSION) \
-		-f docker/observer.Dockerfile \
-		.
-
-docker: runner observer_docker
-
 docker_clean: status
 	docker rmi -f $(BUILDER):latest
 	docker rmi -f $(IMAGE):latest
-	docker rmi -f $(OB_IMAGE):latest
 	docker rmi -f $(BUILDER):$(VERSION)
 	docker rmi -f $(IMAGE):$(VERSION)
-	docker rmi -f $(OB_IMAGE):$(VERSION)
 
 
 save: status
@@ -89,27 +75,19 @@ logs:
 	docker-compose logs -f --tail=10
 
 push_testnet:
-	docker tag $(OB_IMAGE):$(VERSION) $(OB_IMAGE):testnet
-	docker push $(OB_IMAGE):testnet
 	docker tag $(IMAGE):$(VERSION) $(IMAGE):testnet
 	docker push $(IMAGE):testnet
 
 push_bench:
-	docker tag $(OB_IMAGE):$(VERSION) $(OB_IMAGE):bench
-	docker push $(OB_IMAGE):bench
 	docker tag $(IMAGE):$(VERSION) $(IMAGE):bench
 	docker push $(IMAGE):bench
 
 push_staging:
-	docker tag $(OB_IMAGE):$(VERSION) $(OB_IMAGE):staging
-	docker push $(OB_IMAGE):staging
 	docker tag $(IMAGE):$(VERSION) $(IMAGE):staging
 	docker push $(IMAGE):staging
 
 
 push:
-	docker push $(OB_IMAGE):$(VERSION)
-	docker push $(OB_IMAGE):latest
 	docker push $(IMAGE):$(VERSION)
 	docker push $(IMAGE):latest
 
@@ -162,18 +140,6 @@ bin/cql-minerd:
 		-o bin/cql-minerd \
 		github.com/CovenantSQL/CovenantSQL/cmd/cql-minerd
 
-bin/cql-observer.test:
-	$(GOTEST) \
-		-ldflags "$(ldflags_role_client)" \
-		-o bin/cql-observer.test \
-		github.com/CovenantSQL/CovenantSQL/cmd/cql-observer
-
-bin/cql-observer:
-	$(GOBUILD) \
-		-ldflags "$(ldflags_role_client)" \
-		-o bin/cql-observer \
-		github.com/CovenantSQL/CovenantSQL/cmd/cql-observer
-
 bin/cql-utils:
 	$(GOBUILD) \
 		-ldflags "$(ldflags_role_client_simple_log)" \
@@ -186,18 +152,19 @@ bin/cql:
 		-o bin/cql \
 		github.com/CovenantSQL/CovenantSQL/cmd/cql
 
+bin/cql.test:
+	$(GOTEST) \
+		-ldflags "$(ldflags_role_client)" \
+		-o bin/cql.test \
+		github.com/CovenantSQL/CovenantSQL/cmd/cql
+
+
 bin/cql-fuse:
 	$(GOBUILD) \
 		-ldflags "$(ldflags_role_client_simple_log)" \
 		-o bin/cql-fuse \
 		github.com/CovenantSQL/CovenantSQL/cmd/cql-fuse
 
-bin/cql-adapter:
-	$(GOBUILD) \
-		-ldflags "$(ldflags_role_client)" \
-		-o bin/cql-adapter \
-		github.com/CovenantSQL/CovenantSQL/cmd/cql-adapter
-
 bin/cql-mysql-adapter:
 	$(GOBUILD) \
 		-ldflags "$(ldflags_role_client)" \
@@ -210,21 +177,13 @@ bin/cql-faucet:
 		-o bin/cql-faucet \
 		github.com/CovenantSQL/CovenantSQL/cmd/cql-faucet
 
-bin/cql-explorer:
-	$(GOBUILD) \
-		-ldflags "$(ldflags_role_client)" \
-		-o bin/cql-explorer \
-		github.com/CovenantSQL/CovenantSQL/cmd/cql-explorer
-
 bp: bin/cqld.test bin/cqld
 
 miner: bin/cql-minerd.test bin/cql-minerd
 
-observer: bin/cql-observer.test bin/cql-observer
-
-client: bin/cql-utils bin/cql bin/cql-fuse bin/cql-adapter bin/cql-mysql-adapter bin/cql-faucet bin/cql-explorer
+client: bin/cql-utils bin/cql bin/cql.test bin/cql-fuse bin/cql-mysql-adapter bin/cql-faucet
 
-all: bp miner observer client
+all: bp miner client
 
 clean:
 	rm -rf bin/cql*
@@ -232,5 +191,5 @@ clean:
 	rm -f coverage.txt
 
 .PHONY: status start stop logs push push_testnet clean \
-	bin/cqld.test bin/cqld bin/cql-minerd.test bin/cql-minerd bin/cql-utils bin/cql-observer bin/cql-observer.test \
-	bin/cql bin/cql-fuse bin/cql-adapter bin/cql-mysql-adapter bin/cql-faucet bin/cql-explorer
+	bin/cqld.test bin/cqld bin/cql-minerd.test bin/cql-minerd bin/cql-utils \
+	bin/cql bin/cql.test bin/cql-fuse bin/cql-mysql-adapter bin/cql-faucet
diff --git a/README.md b/README.md
index b322ab190..6da536ba9 100644
--- a/README.md
+++ b/README.md
@@ -28,8 +28,9 @@
 
 [中文简介](https://github.com/CovenantSQL/CovenantSQL/blob/develop/README-zh.md)
 
-CovenantSQL is a decentralized, crowdsourcing SQL database on blockchain with features:
+CovenantSQL is a GDPR-compliant SQL database running on Open Internet without central coordination:
 
+- **GDPR-compliant**: Zero pain to be GDPR-compliant.
 - **SQL**: most SQL-92 support.
 - **Decentralize**: decentralize with our consensus algorithm DH-RPC & Kayak.
 - **Privacy**: access with granted permission and Encryption Pass.
@@ -107,10 +108,14 @@ Watch us or [![follow on Twitter](https://img.shields.io/twitter/url/https/twitt
 ## TestNet
 
 - [Quick Start](https://developers.covenantsql.io)
+- [MainChain Explorer](http://scan.covenantsql.io)
+- [SQLChain Explorer](https://explorer.dbhub.org)
+- [Demo & Forum](https://demo.covenantsql.io/forum/)
 
 ## Contact
 
-- [mail us](mailto:webmaster@covenantsql.io)
+- [Mail](mailto:webmaster@covenantsql.io)
+- [Forum](https://demo.covenantsql.io/forum/)
 - <a href="https://twitter.com/intent/follow?screen_name=CovenantLabs">
           <img src="https://img.shields.io/twitter/url/https/twitter.com/fold_left.svg?style=social&label=Follow%20%40CovenantLabs"
               alt="follow on Twitter"></a>
diff --git a/alltest.sh b/alltest.sh
index b762c25d6..31421cda0 100755
--- a/alltest.sh
+++ b/alltest.sh
@@ -5,9 +5,6 @@ set -o pipefail
 set -o nounset
 
 main() {
-  make clean
-  make -j6 bp miner observer
-
   go test -tags "$UNITTESTTAGS" -race -failfast -parallel 16 -cpu 16 -coverprofile main.cover.out $(go list ./... | grep -v CovenantSQL/api)
   go test -tags "$UNITTESTTAGS" -race -failfast -parallel 16 -cpu 16 -coverpkg ./api/...,./rpc/jsonrpc -coverprofile api.cover.out ./api/...
 
diff --git a/bin/docker-entry.sh b/bin/docker-entry.sh
index cb7619ed8..f1da213d6 100755
--- a/bin/docker-entry.sh
+++ b/bin/docker-entry.sh
@@ -12,12 +12,10 @@ blockproducer)
     exec /app/cqld -config "${COVENANT_CONF}" -metric-web "${METRIC_WEB_ADDR}" "${@}"
     ;;
 observer)
-    MAGIC_DOLLAR='$' envsubst < /etc/nginx/conf.d/servers/explorer.conf.template > /etc/nginx/conf.d/default.conf
-    nginx -g 'daemon off;' </dev/null &
-    exec /app/cql-observer -config "${COVENANT_CONF}" -listen "${COVENANTSQL_OBSERVER_ADDR}"
+    exec /app/cql -config "${COVENANT_CONF}" -web "${COVENANTSQL_OBSERVER_ADDR}" "${@}"
     ;;
 adapter)
-    exec /app/cql-adapter -config "${COVENANT_CONF}" "${@}"
+    exec /app/cql -config "${COVENANT_CONF}" -adapter "${COVENANTSQL_ADAPTER_ADDR}" "${@}"
     ;;
 mysql-adapter)
     exec /app/cql-mysql-adapter -config "${COVENANT_CONF}" "${@}"
@@ -28,8 +26,5 @@ cli)
 faucet)
     exec /app/cql-faucet -config ${COVENANT_CONF} "${@}"
     ;;
-explorer)
-    exec /app/cql-explorer -config ${COVENANT_CONF} "${@}"
-    ;;
 esac
 
diff --git a/cmd/cql-adapter/main.go b/cmd/cql-adapter/main.go
deleted file mode 100644
index aee2cfdde..000000000
--- a/cmd/cql-adapter/main.go
+++ /dev/null
@@ -1,89 +0,0 @@
-/*
- * Copyright 2018 The CovenantSQL Authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package main
-
-import (
-	"context"
-	"flag"
-	"fmt"
-	"os"
-	"os/signal"
-	"runtime"
-	"time"
-
-	"golang.org/x/sys/unix"
-
-	"github.com/CovenantSQL/CovenantSQL/crypto/asymmetric"
-	"github.com/CovenantSQL/CovenantSQL/utils"
-	"github.com/CovenantSQL/CovenantSQL/utils/log"
-)
-
-const name = "cql-adapeter"
-
-var (
-	version     = "unknown"
-	configFile  string
-	listenAddr  string
-	password    string
-	showVersion bool
-)
-
-func init() {
-	flag.StringVar(&configFile, "config", "~/.cql/config.yaml", "Config file for adapter")
-	flag.StringVar(&password, "password", "", "Master key password")
-	flag.StringVar(&listenAddr, "listen", "", "Listen address for adapter api")
-	flag.BoolVar(&asymmetric.BypassSignature, "bypass-signature", false,
-		"Disable signature sign and verify, for testing")
-	flag.BoolVar(&showVersion, "version", false, "Show version information and exit")
-}
-
-func main() {
-	flag.Parse()
-	if showVersion {
-		fmt.Printf("%v %v %v %v %v\n",
-			name, version, runtime.GOOS, runtime.GOARCH, runtime.Version())
-		os.Exit(0)
-	}
-
-	configFile = utils.HomeDirExpand(configFile)
-
-	flag.Visit(func(f *flag.Flag) {
-		log.Infof("args %#v : %s", f.Name, f.Value)
-	})
-
-	server, err := NewHTTPAdapter(listenAddr, configFile, password)
-	if err != nil {
-		log.WithError(err).Fatal("init adapter failed")
-		return
-	}
-
-	stop := make(chan os.Signal, 1)
-	signal.Notify(stop, os.Interrupt, unix.SIGTERM)
-
-	log.Info("start adapter")
-	if err = server.Serve(); err != nil {
-		log.WithError(err).Fatal("start adapter failed")
-		return
-	}
-
-	<-stop
-
-	ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
-	defer cancel()
-	server.Shutdown(ctx)
-	log.Info("stopped adapter")
-}
diff --git a/cmd/cql-explorer/README.md b/cmd/cql-explorer/README.md
deleted file mode 100644
index 3062e854d..000000000
--- a/cmd/cql-explorer/README.md
+++ /dev/null
@@ -1,182 +0,0 @@
-This doc introduce the usage of CovenantSQL block producer chain explorer server.
-
-## Prerequisites
-
-Make sure the ```$GOPATH/bin``` is in your ```$PATH```, download/build the explorer binary.
-
-```shell
-$ go get github.com/CovenantSQL/CovenantSQL/cmd/cql-explorer
-```
-
-Adapter requires a CovenantSQL ```config.yaml``` which can by generated by configuration generator.  
-
-### Generating Default Config File
-
-Generate the main configuration file. Same as [Generating Default Config File in Golang Client Doc](https://github.com/CovenantSQL/CovenantSQL/tree/develop/client#generating-default-config-file). An existing configuration file can also be used.
-
-## Explorer Usage
-
-### Start
-
-Start the explorer by following commands:
-
-```shell
-$ cql-explorer
-```
-
-The available options are:
-
-```shell
-$ cql-explorer --help
-Usage of cql-explorer:
-  -config string
-    	Config file path (default "~/.cql/config.yaml")
-  -interval duration
-    	New block check interval for explorer (default 2s)
-  -listen string
-    	Listen address for http explorer api (default "127.0.0.1:4665")
-  -password string
-    	Master key password for covenantsql
-```
-
-### API
-
-#### Query Synced Head Block
-
-**GET** /v1/head
-
-##### Request
-
-##### Response
-
-```json
-{
-   "success" : true,
-   "status" : "ok",
-   "data" : {
-      "block" : {
-         "txs" : [],
-         "hash" : "20ba21af54da3e17252fb4b6b7331fb6f36aca1b9b793597af6ef46faad34dea",
-         "timestamp" : 1540278575120.34,
-         "version" : 1,
-         "count" : 561,
-         "producer" : "8d7604acfdb391891a4c795f0939425b6d58bd50a81e579d15f06ecd381ad549",
-         "height" : 3040488,
-         "parent" : "f9c4f9c7a1dcbcf14a13eb91a007b33672f1f8a261738f5a25fee27c3ccaa584"
-      }
-   }
-}
-```
-
-#### Query Block by _COUNT_
-
-**GET** /v1/count/{count}
-
-##### Request
-
-__count__: count of specified block, 0 for genesis block
-
-##### Response
-
-```json
-{
-   "success" : true,
-   "status" : "ok",
-   "data" : {
-      "block" : {
-         "version" : 1,
-         "height" : 0,
-         "count" : 0,
-         "timestamp" : 1534197599120,
-         "hash" : "f745ca6427237aac858dd3c7f2df8e6f3c18d0f1c164e07a1c6b8eebeba6b154",
-         "txs" : [],
-         "parent" : "0000000000000000000000000000000000000000000000000000000000000001",
-         "producer" : "0000000000000000000000000000000000000000000000000000000000000001"
-      }
-   }
-}
-```
-
-#### Query Block by _HASH_
-
-**GET** /v1/block/{hash}
-
-##### Request
-
-__hash__: hash of specified block
-
-##### Response
-
-```json
-{
-   "success" : true,
-   "status" : "ok",
-   "data" : {
-      "block" : {
-         "version" : 1,
-         "height" : 0,
-         "count" : 0,
-         "timestamp" : 1534197599120,
-         "hash" : "f745ca6427237aac858dd3c7f2df8e6f3c18d0f1c164e07a1c6b8eebeba6b154",
-         "txs" : [],
-         "parent" : "0000000000000000000000000000000000000000000000000000000000000001",
-         "producer" : "0000000000000000000000000000000000000000000000000000000000000001"
-      }
-   }
-}
-```
-
-#### Query Block by _HEIGHT_
-
-**GET** /v1/height/{height}
-
-##### Request
-
-__height__: height of specified block, 0 for genesis block (height is related to block produce time and interval)
-
-##### Response
-
-```json
-{
-   "success" : true,
-   "status" : "ok",
-   "data" : {
-      "block" : {
-         "version" : 1,
-         "height" : 0,
-         "count" : 0,
-         "timestamp" : 1534197599120,
-         "hash" : "f745ca6427237aac858dd3c7f2df8e6f3c18d0f1c164e07a1c6b8eebeba6b154",
-         "txs" : [],
-         "parent" : "0000000000000000000000000000000000000000000000000000000000000001",
-         "producer" : "0000000000000000000000000000000000000000000000000000000000000001"
-      }
-   }
-}
-```
-
-#### Query Transaction by _HASH_
-
-**GET** /v1/tx/{hash}
-
-##### Request
-
-__hash__: hash of specified tx
-
-##### Response
-
-```json
-{
-    "success": true,
-    "status": "ok",
-    "data": {
-        "tx": {
-            "nonce": 11616,
-            "amount": 1225,
-            "sender": "00000bef611d346c0cbe1beaa76e7f0ed705a194fdf9ac3a248ec70e9c198bf9",
-            "receiver": "676b12fef8732ac78a97ea5dba0977bbbabc48f64eee66f09be89a589297e567",
-            "type": "Transfer"
-        }
-    }
-}
-```
diff --git a/cmd/cql-explorer/api.go b/cmd/cql-explorer/api.go
deleted file mode 100644
index dcbca8218..000000000
--- a/cmd/cql-explorer/api.go
+++ /dev/null
@@ -1,328 +0,0 @@
-/*
- * Copyright 2018 The CovenantSQL Authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package main
-
-import (
-	"context"
-	"encoding/json"
-	"fmt"
-	"net/http"
-	"strconv"
-	"time"
-
-	"github.com/gorilla/mux"
-
-	pi "github.com/CovenantSQL/CovenantSQL/blockproducer/interfaces"
-	"github.com/CovenantSQL/CovenantSQL/crypto/hash"
-	"github.com/CovenantSQL/CovenantSQL/proto"
-	pt "github.com/CovenantSQL/CovenantSQL/types"
-	"github.com/CovenantSQL/CovenantSQL/utils/log"
-)
-
-var (
-	apiTimeout = time.Second * 10
-)
-
-func sendResponse(code int, success bool, msg interface{}, data interface{}, rw http.ResponseWriter) {
-	msgStr := "ok"
-	if msg != nil {
-		msgStr = fmt.Sprint(msg)
-	}
-	rw.WriteHeader(code)
-	json.NewEncoder(rw).Encode(map[string]interface{}{
-		"status":  msgStr,
-		"success": success,
-		"data":    data,
-	})
-}
-
-func sendError(err error, rw http.ResponseWriter) {
-	if err == ErrNotFound {
-		sendResponse(404, false, err, nil, rw)
-	} else if err == ErrBadRequest {
-		sendResponse(400, false, err, nil, rw)
-	} else if err != nil {
-		sendResponse(500, false, err, nil, rw)
-	} else {
-		sendResponse(200, true, nil, nil, rw)
-	}
-}
-
-func getUintFromVars(field string, r *http.Request) (value uint32, err error) {
-	vars := mux.Vars(r)
-	valueStr := vars[field]
-	if valueStr == "" {
-		err = ErrBadRequest
-		return
-	}
-
-	valueUint, err := strconv.ParseUint(valueStr, 10, 32)
-	if err != nil {
-		return
-	}
-
-	value = uint32(valueUint)
-
-	return
-}
-
-type explorerAPI struct {
-	service *Service
-}
-
-func (a *explorerAPI) GetHighestBlock(rw http.ResponseWriter, r *http.Request) {
-	count, err := a.service.getHighestCount()
-	if err != nil {
-		sendError(err, rw)
-		return
-	}
-
-	block, _, height, err := a.service.getBlockByCount(count)
-	if err != nil {
-		sendError(err, rw)
-		return
-	}
-
-	sendResponse(200, true, nil, a.formatBlock(count, height, block), rw)
-}
-
-func (a *explorerAPI) GetBlockByCount(rw http.ResponseWriter, r *http.Request) {
-	count, err := getUintFromVars("count", r)
-	if err != nil {
-		sendError(err, rw)
-		return
-	}
-
-	block, _, height, err := a.service.getBlockByCount(count)
-	if err != nil {
-		sendError(err, rw)
-		return
-	}
-
-	sendResponse(200, true, nil, a.formatBlock(count, height, block), rw)
-}
-
-func (a *explorerAPI) GetBlockByHeight(rw http.ResponseWriter, r *http.Request) {
-	height, err := getUintFromVars("height", r)
-	if err != nil {
-		sendError(err, rw)
-		return
-	}
-
-	block, count, _, err := a.service.getBlockByHeight(height)
-	if err != nil {
-		sendError(err, rw)
-		return
-	}
-
-	sendResponse(200, true, nil, a.formatBlock(count, height, block), rw)
-}
-
-func (a *explorerAPI) GetBlockByHash(rw http.ResponseWriter, r *http.Request) {
-	h, err := a.getHash(r)
-	if err != nil {
-		sendError(err, rw)
-		return
-	}
-
-	block, count, height, err := a.service.getBlockByHash(h)
-	if err != nil {
-		sendError(err, rw)
-		return
-	}
-
-	sendResponse(200, true, nil, a.formatBlock(count, height, block), rw)
-}
-
-func (a *explorerAPI) GetTxByHash(rw http.ResponseWriter, r *http.Request) {
-	h, err := a.getHash(r)
-	if err != nil {
-		sendError(err, rw)
-		return
-	}
-
-	tx, count, height, err := a.service.getTxByHash(h)
-	if err != nil {
-		sendError(err, rw)
-		return
-	}
-
-	sendResponse(200, true, nil, a.formatTx(count, height, tx), rw)
-}
-
-func (a *explorerAPI) formatTime(t time.Time) float64 {
-	return float64(t.UnixNano()) / 1e6
-}
-
-func (a *explorerAPI) formatBlock(count uint32, height uint32, b *pt.BPBlock) map[string]interface{} {
-	txs := make([]map[string]interface{}, 0, len(b.Transactions))
-
-	for _, tx := range b.Transactions {
-		txs = append(txs, a.formatRawTx(tx))
-	}
-
-	return map[string]interface{}{
-		"block": map[string]interface{}{
-			"height":    height,
-			"count":     count,
-			"hash":      b.BlockHash().String(),
-			"parent":    b.ParentHash().String(),
-			"timestamp": a.formatTime(b.Timestamp()),
-			"version":   b.SignedHeader.Version,
-			"producer":  b.SignedHeader.Producer.String(),
-			"txs":       txs,
-		},
-	}
-}
-
-func (a *explorerAPI) formatRawTx(t pi.Transaction) (res map[string]interface{}) {
-	if t == nil {
-		return nil
-	}
-
-	switch tx := t.(type) {
-	case *pt.Transfer:
-		res = map[string]interface{}{
-			"nonce":    tx.Nonce,
-			"sender":   tx.Sender.String(),
-			"receiver": tx.Receiver.String(),
-			"amount":   tx.Amount,
-		}
-	case *pt.Billing:
-		res = a.formatTxBilling(tx)
-	case *pt.BaseAccount:
-		res = map[string]interface{}{
-			"next_nonce":       tx.NextNonce,
-			"address":          tx.Address,
-			"stable_balance":   tx.TokenBalance[pt.Particle],
-			"covenant_balance": tx.TokenBalance[pt.Wave],
-			"rating":           tx.Rating,
-		}
-	case *pi.TransactionWrapper:
-		res = a.formatRawTx(tx.Unwrap())
-		return
-	default:
-		// for unknown transactions
-		if txBytes, err := json.Marshal(tx); err != nil {
-			res = map[string]interface{}{
-				"error": err.Error(),
-			}
-		} else if err = json.Unmarshal(txBytes, &res); err != nil {
-			res = map[string]interface{}{
-				"error": err.Error(),
-			}
-		}
-	}
-
-	res["type"] = t.GetTransactionType().String()
-
-	return
-}
-
-func (a *explorerAPI) formatTxBilling(tx *pt.Billing) (res map[string]interface{}) {
-	if tx == nil {
-		return
-	}
-
-	return map[string]interface{}{
-		"nonce":    tx.Nonce,
-		"producer": tx.Producer.String(),
-		"billing_request": func(br pt.BillingRequest) map[string]interface{} {
-			return map[string]interface{}{
-				"database_id": br.Header.DatabaseID,
-				"low_block":   br.Header.LowBlock.String(),
-				"low_height":  br.Header.LowHeight,
-				"high_block":  br.Header.HighBlock.String(),
-				"high_height": br.Header.HighHeight,
-				"gas_amounts": func(gasAmounts []*proto.AddrAndGas) (d []map[string]interface{}) {
-					for _, g := range gasAmounts {
-						d = append(d, map[string]interface{}{
-							"address": g.AccountAddress.String(),
-							"node":    g.RawNodeID.String(),
-							"amount":  g.GasAmount,
-						})
-					}
-					return
-				}(br.Header.GasAmounts),
-			}
-		}(tx.BillingRequest),
-		"receivers": func(receivers []*proto.AccountAddress) (s []string) {
-			for _, r := range receivers {
-				s = append(s, r.String())
-			}
-			return
-		}(tx.Receivers),
-		"fees":    tx.Fees,
-		"rewards": tx.Rewards,
-	}
-}
-
-func (a *explorerAPI) formatTx(count uint32, height uint32, tx pi.Transaction) map[string]interface{} {
-	var res map[string]interface{}
-
-	if res = a.formatRawTx(tx); res != nil {
-		res["height"] = height
-		res["count"] = count
-	}
-
-	return map[string]interface{}{
-		"tx": res,
-	}
-}
-
-func (a *explorerAPI) getHash(r *http.Request) (h *hash.Hash, err error) {
-	vars := mux.Vars(r)
-	hStr := vars["hash"]
-	return hash.NewHashFromStr(hStr)
-}
-
-func startAPI(service *Service, listenAddr string) (server *http.Server, err error) {
-	router := mux.NewRouter()
-	router.HandleFunc("/", func(rw http.ResponseWriter, r *http.Request) {
-		sendResponse(http.StatusOK, true, nil, nil, rw)
-	}).Methods("GET")
-
-	api := &explorerAPI{
-		service: service,
-	}
-	v1Router := router.PathPrefix("/v1").Subrouter()
-	v1Router.HandleFunc("/tx/{hash}", api.GetTxByHash).Methods("GET")
-	v1Router.HandleFunc("/height/{height:[0-9]+}", api.GetBlockByHeight).Methods("GET")
-	v1Router.HandleFunc("/block/{hash}", api.GetBlockByHash).Methods("GET")
-	v1Router.HandleFunc("/count/{count:[0-9]+}", api.GetBlockByCount).Methods("GET")
-	v1Router.HandleFunc("/head", api.GetHighestBlock).Methods("GET")
-
-	server = &http.Server{
-		Addr:         listenAddr,
-		WriteTimeout: apiTimeout,
-		ReadTimeout:  apiTimeout,
-		IdleTimeout:  apiTimeout,
-		Handler:      router,
-	}
-
-	go func() {
-		if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
-			log.WithError(err).Fatal("start api server failed")
-		}
-	}()
-
-	return server, err
-}
-
-func stopAPI(server *http.Server) (err error) {
-	return server.Shutdown(context.Background())
-}
diff --git a/cmd/cql-explorer/errors.go b/cmd/cql-explorer/errors.go
deleted file mode 100644
index 22937dac8..000000000
--- a/cmd/cql-explorer/errors.go
+++ /dev/null
@@ -1,32 +0,0 @@
-/*
- * Copyright 2018 The CovenantSQL Authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package main
-
-import "github.com/pkg/errors"
-
-var (
-	// ErrNilBlock represents nil block received.
-	ErrNilBlock = errors.New("nil block received")
-	// ErrNilTransaction represents nil transaction received.
-	ErrNilTransaction = errors.New("nil transaction received")
-	// ErrStopped defines error on explorer service has already stopped
-	ErrStopped = errors.New("explorer service has stopped")
-	// ErrNotFound defines error on failed to found specified resource
-	ErrNotFound = errors.New("resource not found")
-	// ErrBadRequest defines errors on error input field.
-	ErrBadRequest = errors.New("request field not fulfilled")
-)
diff --git a/cmd/cql-explorer/main.go b/cmd/cql-explorer/main.go
deleted file mode 100644
index b1fbca26f..000000000
--- a/cmd/cql-explorer/main.go
+++ /dev/null
@@ -1,125 +0,0 @@
-/*
- * Copyright 2018 The CovenantSQL Authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package main
-
-import (
-	"flag"
-	"fmt"
-	"math/rand"
-	"net/http"
-	"os"
-	"os/signal"
-	"runtime"
-	"syscall"
-	"time"
-
-	"github.com/CovenantSQL/CovenantSQL/client"
-	"github.com/CovenantSQL/CovenantSQL/utils"
-	"github.com/CovenantSQL/CovenantSQL/utils/log"
-)
-
-const name = "cql-explorer"
-
-var (
-	version = "unknown"
-)
-
-var (
-	// config
-	configFile    string
-	password      string
-	listenAddr    string
-	checkInterval time.Duration
-	showVersion   bool
-)
-
-func init() {
-	flag.StringVar(&configFile, "config", "~/.cql/config.yaml", "Config file path")
-	flag.StringVar(&listenAddr, "listen", "127.0.0.1:4665", "Listen address for http explorer api")
-	flag.DurationVar(&checkInterval, "interval", time.Second*2, "New block check interval for explorer")
-	flag.StringVar(&password, "password", "", "Master key password for covenantsql")
-	flag.BoolVar(&showVersion, "version", false, "Show version information and exit")
-}
-
-func main() {
-	// set random
-	rand.Seed(time.Now().UnixNano())
-	log.SetLevel(log.DebugLevel)
-	flag.Parse()
-	if showVersion {
-		fmt.Printf("%v %v %v %v %v\n",
-			name, version, runtime.GOOS, runtime.GOARCH, runtime.Version())
-		os.Exit(0)
-	}
-
-	configFile = utils.HomeDirExpand(configFile)
-
-	flag.Visit(func(f *flag.Flag) {
-		log.Infof("args %#v : %s", f.Name, f.Value)
-	})
-
-	// init client
-	var err error
-	if err = client.Init(configFile, []byte(password)); err != nil {
-		log.WithError(err).Fatal("init node failed")
-		return
-	}
-
-	// start service
-	var service *Service
-	if service, err = NewService(checkInterval); err != nil {
-		log.WithError(err).Fatal("init service failed")
-		return
-	}
-
-	// start api
-	var httpServer *http.Server
-	if httpServer, err = startAPI(service, listenAddr); err != nil {
-		log.WithError(err).Fatal("start explorer api failed")
-		return
-	}
-
-	// start subscription
-	if err = service.start(); err != nil {
-		log.WithError(err).Fatal("start service failed")
-		return
-	}
-
-	signalCh := make(chan os.Signal, 1)
-	signal.Notify(
-		signalCh,
-		syscall.SIGINT,
-		syscall.SIGTERM,
-	)
-	signal.Ignore(syscall.SIGHUP, syscall.SIGTTIN, syscall.SIGTTOU)
-
-	<-signalCh
-
-	// stop explorer api
-	if err = stopAPI(httpServer); err != nil {
-		log.WithError(err).Fatal("stop explorer api failed")
-		return
-	}
-
-	// stop subscription
-	if err = service.stop(); err != nil {
-		log.WithError(err).Fatal("stop service failed")
-		return
-	}
-
-	log.Info("explorer stopped")
-}
diff --git a/cmd/cql-explorer/service.go b/cmd/cql-explorer/service.go
deleted file mode 100644
index 55233c66f..000000000
--- a/cmd/cql-explorer/service.go
+++ /dev/null
@@ -1,460 +0,0 @@
-/*
- * Copyright 2018 The CovenantSQL Authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package main
-
-import (
-	"bytes"
-	"encoding/binary"
-	"path/filepath"
-	"sync"
-	"sync/atomic"
-	"time"
-
-	"github.com/syndtr/goleveldb/leveldb"
-	"github.com/syndtr/goleveldb/leveldb/util"
-
-	pi "github.com/CovenantSQL/CovenantSQL/blockproducer/interfaces"
-	"github.com/CovenantSQL/CovenantSQL/conf"
-	"github.com/CovenantSQL/CovenantSQL/crypto/hash"
-	"github.com/CovenantSQL/CovenantSQL/proto"
-	"github.com/CovenantSQL/CovenantSQL/route"
-	"github.com/CovenantSQL/CovenantSQL/rpc"
-	pt "github.com/CovenantSQL/CovenantSQL/types"
-	"github.com/CovenantSQL/CovenantSQL/utils"
-	"github.com/CovenantSQL/CovenantSQL/utils/log"
-)
-
-const (
-	dbFileName = "explorer.db"
-)
-
-var (
-	// storage keys
-	blockKeyPrefix    = []byte("BLOCK_")
-	blockHashPrefix   = []byte("HASH_")
-	blockHeightPrefix = []byte("HEIGHT_")
-	txKeyPrefix       = []byte("TX_")
-)
-
-// Service defines the main chain explorer service structure.
-type Service struct {
-	db *leveldb.DB
-
-	caller    *rpc.Caller
-	stopped   int32
-	stopCh    chan struct{}
-	triggerCh chan struct{}
-	wg        sync.WaitGroup
-
-	// new block check interval
-	checkInterval time.Duration
-
-	// next block to fetch
-	nextBlockToFetch uint32
-}
-
-// NewService creates new explorer service handler.
-func NewService(checkInterval time.Duration) (service *Service, err error) {
-	// open explorer database
-	dbFile := filepath.Join(conf.GConf.WorkingRoot, dbFileName)
-	db, err := leveldb.OpenFile(dbFile, nil)
-	if err != nil {
-		return
-	}
-
-	defer func() {
-		if err != nil {
-			db.Close()
-		}
-	}()
-
-	// init service
-	service = &Service{
-		db:            db,
-		caller:        rpc.NewCaller(),
-		stopCh:        make(chan struct{}),
-		triggerCh:     make(chan struct{}, 1),
-		checkInterval: checkInterval,
-	}
-
-	return
-}
-
-func (s *Service) start() (err error) {
-	if atomic.LoadInt32(&s.stopped) == 1 {
-		// stopped
-		return ErrStopped
-	}
-
-	if err = s.getSubscriptionCheckpoint(); err != nil {
-		return
-	}
-
-	// start subscription worker
-	s.wg.Add(1)
-	go s.subscriptionWorker()
-
-	return
-}
-
-func (s *Service) getBlockByCount(c uint32) (b *pt.BPBlock, count uint32, height uint32, err error) {
-	var bKey []byte
-	bKey = append(bKey, blockKeyPrefix...)
-	bKey = append(bKey, uint32ToBytes(c)...)
-
-	it := s.db.NewIterator(util.BytesPrefix(bKey), nil)
-	if it.First() {
-		// decode
-		bKeyLen := len(bKey)
-		hBytes := it.Key()[bKeyLen : bKeyLen+4]
-		height = bytesToUint32(hBytes)
-		count = c
-		err = utils.DecodeMsgPack(it.Value(), &b)
-	} else {
-		// not found
-		err = ErrNotFound
-	}
-	it.Release()
-
-	if err != nil {
-		// ignore iterator error
-		it.Error()
-		return
-	}
-
-	err = it.Error()
-
-	return
-}
-
-func (s *Service) getBlockByHash(h *hash.Hash) (b *pt.BPBlock, count uint32, height uint32, err error) {
-	if h == nil {
-		err = ErrNotFound
-		return
-	}
-
-	var bKey []byte
-	bKey = append(bKey, blockHashPrefix...)
-	bKey = append(bKey, h[:]...)
-
-	var bCountData []byte
-	if bCountData, err = s.db.Get(bKey, nil); err != nil {
-		if err == leveldb.ErrNotFound {
-			err = ErrNotFound
-		}
-		return
-	}
-
-	count = bytesToUint32(bCountData)
-	return s.getBlockByCount(count)
-}
-
-func (s *Service) getBlockByHeight(h uint32) (b *pt.BPBlock, count uint32, height uint32, err error) {
-	var bKey []byte
-	bKey = append(bKey, blockHeightPrefix...)
-	bKey = append(bKey, uint32ToBytes(h)...)
-
-	var bCountData []byte
-	if bCountData, err = s.db.Get(bKey, nil); err != nil {
-		if err == leveldb.ErrNotFound {
-			err = ErrNotFound
-		}
-		return
-	}
-
-	count = bytesToUint32(bCountData)
-	return s.getBlockByCount(count)
-}
-
-func (s *Service) getTxByHash(h *hash.Hash) (tx pi.Transaction, c uint32, height uint32, err error) {
-	if h == nil {
-		err = ErrNotFound
-		return
-	}
-
-	var txKey []byte
-	txKey = append(txKey, txKeyPrefix...)
-	txKey = append(txKey, h[:]...)
-
-	var bCountData []byte
-	if bCountData, err = s.db.Get(txKeyPrefix, nil); err != nil {
-		if err == leveldb.ErrNotFound {
-			err = ErrNotFound
-		}
-		return
-	}
-
-	c = bytesToUint32(bCountData)
-
-	var b *pt.BPBlock
-	if b, _, height, err = s.getBlockByCount(c); err != nil {
-		return
-	}
-
-	if b == nil || b.Transactions == nil {
-		err = ErrNotFound
-		return
-	}
-
-	for _, curTx := range b.Transactions {
-		if curTx == nil {
-			continue
-		}
-
-		if curH := curTx.Hash(); h.IsEqual(&curH) {
-			tx = curTx
-			break
-		}
-	}
-
-	if tx == nil {
-		err = ErrNotFound
-		return
-	}
-
-	return
-}
-
-func (s *Service) getHighestCount() (c uint32, err error) {
-	// load previous committed counts
-	it := s.db.NewIterator(util.BytesPrefix(blockKeyPrefix), nil)
-	if it.Last() {
-		// decode block count from key
-		blockKey := it.Key()
-		prefixLen := len(blockKeyPrefix)
-		c = bytesToUint32(blockKey[prefixLen : prefixLen+4])
-	} else {
-		err = ErrNotFound
-	}
-	it.Release()
-
-	if err != nil {
-		it.Error()
-		return
-	}
-
-	err = it.Error()
-
-	return
-}
-
-func (s *Service) getSubscriptionCheckpoint() (err error) {
-	var lastBlockCount uint32
-	if lastBlockCount, err = s.getHighestCount(); err != nil {
-		log.WithError(err).Warning("get last block failed")
-
-		if err == ErrNotFound {
-			// not found, set last block count to 0
-			log.Info("set current block count fetch head to 0")
-			err = nil
-			atomic.StoreUint32(&s.nextBlockToFetch, 0)
-		}
-
-		return
-	}
-
-	log.WithFields(log.Fields{
-		"count": lastBlockCount,
-	}).Info("fetched last block count")
-
-	atomic.StoreUint32(&s.nextBlockToFetch, lastBlockCount+1)
-
-	return
-}
-
-func (s *Service) subscriptionWorker() {
-	defer s.wg.Done()
-
-	log.Info("started subscription worker")
-	for {
-		select {
-		case <-s.stopCh:
-			log.Info("exited subscription worker")
-			return
-		case <-s.triggerCh:
-		case <-time.After(s.checkInterval):
-		}
-
-		// request block producer for next block
-		s.requestBlock()
-	}
-}
-
-func (s *Service) requestBlock() {
-	if atomic.LoadInt32(&s.stopped) == 1 {
-		return
-	}
-
-	blockCount := atomic.LoadUint32(&s.nextBlockToFetch)
-	log.WithFields(log.Fields{"count": blockCount}).Info("try fetch next block")
-
-	req := &pt.FetchBlockByCountReq{Count: blockCount}
-	resp := &pt.FetchBlockResp{}
-
-	if err := s.requestBP(route.MCCFetchBlockByCount.String(), req, resp); err != nil {
-		// fetch block failed
-		log.WithError(err).Warning("fetch block failed，wait for next round")
-		return
-	}
-
-	// process block
-	if err := s.processBlock(blockCount, resp.Height, resp.Block); err != nil {
-		log.WithError(err).Warning("process block failed, try fetch/process again")
-		return
-	}
-
-	atomic.AddUint32(&s.nextBlockToFetch, 1)
-
-	// last fetch success, trigger next fetch for fast sync
-	select {
-	case s.triggerCh <- struct{}{}:
-	default:
-	}
-}
-
-func (s *Service) processBlock(c uint32, h uint32, b *pt.BPBlock) (err error) {
-	if b == nil {
-		log.WithField("count", c).Warning("processed nil block")
-		return ErrNilBlock
-	}
-
-	log.WithFields(log.Fields{
-		"hash":   b.BlockHash(),
-		"parent": b.ParentHash(),
-		"height": h,
-		"count":  c,
-	}).Info("process new block")
-
-	if err = s.saveTransactions(c, b.Transactions); err != nil {
-		return
-	}
-
-	err = s.saveBlock(c, h, b)
-
-	return
-}
-
-func (s *Service) saveTransactions(c uint32, txs []pi.Transaction) (err error) {
-	if txs == nil || len(txs) == 0 {
-		return
-	}
-
-	for _, t := range txs {
-		if err = s.saveTransaction(c, t); err != nil {
-			return
-		}
-	}
-
-	return
-}
-
-func (s *Service) saveTransaction(c uint32, tx pi.Transaction) (err error) {
-	if tx == nil {
-		return ErrNilTransaction
-	}
-
-	txHash := tx.Hash()
-
-	var txKey []byte
-
-	txKey = append(txKey, txKeyPrefix...)
-	txKey = append(txKey, txHash[:]...)
-	txData := uint32ToBytes(c)
-
-	err = s.db.Put(txKey, txData, nil)
-
-	return
-}
-
-func (s *Service) saveBlock(c uint32, h uint32, b *pt.BPBlock) (err error) {
-	if b == nil {
-		return ErrNilBlock
-	}
-
-	bHash := b.BlockHash()
-
-	var buf *bytes.Buffer
-
-	if buf, err = utils.EncodeMsgPack(b); err != nil {
-		return
-	}
-
-	cBytes := uint32ToBytes(c)
-	hBytes := uint32ToBytes(h)
-
-	var bKey, bHashKey, bHeightKey []byte
-
-	bKey = append(bKey, blockKeyPrefix...)
-	bKey = append(bKey, cBytes...)
-	bKey = append(bKey, hBytes...)
-
-	bHashKey = append(bHashKey, blockHashPrefix...)
-	bHashKey = append(bHashKey, bHash[:]...)
-
-	bHeightKey = append(bHeightKey, blockHeightPrefix...)
-	bHeightKey = append(bHeightKey, hBytes...)
-
-	if err = s.db.Put(bKey, buf.Bytes(), nil); err != nil {
-		return
-	}
-
-	if err = s.db.Put(bHashKey, cBytes, nil); err != nil {
-		return
-	}
-
-	err = s.db.Put(bHeightKey, cBytes, nil)
-
-	return
-}
-
-func (s *Service) requestBP(method string, request interface{}, response interface{}) (err error) {
-	var bpNodeID proto.NodeID
-	if bpNodeID, err = rpc.GetCurrentBP(); err != nil {
-		return
-	}
-	return s.caller.CallNode(bpNodeID, method, request, response)
-}
-
-func (s *Service) stop() (err error) {
-	if !atomic.CompareAndSwapInt32(&s.stopped, 0, 1) {
-		// stopped
-		return ErrStopped
-	}
-
-	log.Info("stop subscription")
-
-	select {
-	case <-s.stopCh:
-	default:
-		close(s.stopCh)
-	}
-
-	s.wg.Wait()
-	s.db.Close()
-
-	return
-}
-
-func uint32ToBytes(h uint32) (data []byte) {
-	data = make([]byte, 4)
-	binary.BigEndian.PutUint32(data, h)
-	return
-}
-
-func bytesToUint32(data []byte) uint32 {
-	return binary.BigEndian.Uint32(data)
-}
diff --git a/cmd/cql-faucet/main.go b/cmd/cql-faucet/main.go
index 333bbe77d..6debac8fd 100644
--- a/cmd/cql-faucet/main.go
+++ b/cmd/cql-faucet/main.go
@@ -22,12 +22,9 @@ import (
 	"fmt"
 	"net/http"
 	"os"
-	"os/signal"
 	"runtime"
 	"time"
 
-	"golang.org/x/sys/unix"
-
 	"github.com/CovenantSQL/CovenantSQL/client"
 	"github.com/CovenantSQL/CovenantSQL/crypto/asymmetric"
 	"github.com/CovenantSQL/CovenantSQL/utils"
@@ -106,10 +103,7 @@ func main() {
 
 	log.Info("started faucet")
 
-	stop := make(chan os.Signal, 1)
-	signal.Notify(stop, os.Interrupt, unix.SIGTERM)
-
-	<-stop
+	<-utils.WaitForExit()
 
 	// stop verifier
 	v.stop()
diff --git a/cmd/cql-fuse/main.go b/cmd/cql-fuse/main.go
index c66401960..5eae842aa 100644
--- a/cmd/cql-fuse/main.go
+++ b/cmd/cql-fuse/main.go
@@ -70,7 +70,6 @@ import (
 	"flag"
 	"fmt"
 	"os"
-	"os/signal"
 
 	"bazil.org/fuse"
 	"bazil.org/fuse/fs"
@@ -152,14 +151,9 @@ func main() {
 	log.Infof("DB: %s mount on %s succeed", dsn, mountPoint)
 
 	go func() {
-		sig := make(chan os.Signal, 1)
-		signal.Notify(sig, os.Interrupt)
-		for range sig {
-			if err := fuse.Unmount(mountPoint); err != nil {
-				log.Printf("Signal received, but could not unmount: %s", err)
-			} else {
-				break
-			}
+		<-utils.WaitForExit()
+		if err := fuse.Unmount(mountPoint); err != nil {
+			log.Printf("Signal received, but could not unmount: %s", err)
 		}
 	}()
 
diff --git a/cmd/cql-minerd/main.go b/cmd/cql-minerd/main.go
index b1170252c..f8c02c561 100644
--- a/cmd/cql-minerd/main.go
+++ b/cmd/cql-minerd/main.go
@@ -24,9 +24,7 @@ import (
 	"net/http"
 	_ "net/http/pprof"
 	"os"
-	"os/signal"
 	"runtime"
-	"syscall"
 	"time"
 
 	graphite "github.com/cyberdelia/go-metrics-graphite"
@@ -39,6 +37,7 @@ import (
 	"github.com/CovenantSQL/CovenantSQL/rpc"
 	"github.com/CovenantSQL/CovenantSQL/utils"
 	"github.com/CovenantSQL/CovenantSQL/utils/log"
+	_ "github.com/CovenantSQL/CovenantSQL/utils/log/debug"
 	"github.com/CovenantSQL/CovenantSQL/utils/trace"
 	"github.com/CovenantSQL/CovenantSQL/worker"
 )
@@ -231,14 +230,6 @@ func main() {
 		server.Stop()
 	}()
 
-	signalCh := make(chan os.Signal, 1)
-	signal.Notify(
-		signalCh,
-		syscall.SIGINT,
-		syscall.SIGTERM,
-	)
-	signal.Ignore(syscall.SIGHUP, syscall.SIGTTIN, syscall.SIGTTOU)
-
 	if metricLog {
 		go metrics.Log(metrics.DefaultRegistry, 5*time.Second, log.StandardLogger())
 	}
@@ -270,7 +261,7 @@ func main() {
 		defer trace.Stop()
 	}
 
-	<-signalCh
+	<-utils.WaitForExit()
 	utils.StopProfile()
 
 	log.Info("miner stopped")
diff --git a/cmd/cql-mysql-adapter/main.go b/cmd/cql-mysql-adapter/main.go
index f34419fde..81a851203 100644
--- a/cmd/cql-mysql-adapter/main.go
+++ b/cmd/cql-mysql-adapter/main.go
@@ -20,11 +20,8 @@ import (
 	"flag"
 	"fmt"
 	"os"
-	"os/signal"
 	"runtime"
 
-	"golang.org/x/sys/unix"
-
 	"github.com/CovenantSQL/CovenantSQL/client"
 	"github.com/CovenantSQL/CovenantSQL/crypto/asymmetric"
 	"github.com/CovenantSQL/CovenantSQL/utils"
@@ -79,9 +76,6 @@ func main() {
 		return
 	}
 
-	stop := make(chan os.Signal, 1)
-	signal.Notify(stop, os.Interrupt, unix.SIGTERM)
-
 	server, err := NewServer(listenAddr, mysqlUser, mysqlPassword)
 	if err != nil {
 		log.WithError(err).Fatal("init server failed")
@@ -92,7 +86,7 @@ func main() {
 
 	log.Info("start mysql adapter")
 
-	<-stop
+	<-utils.WaitForExit()
 
 	server.Shutdown()
 
diff --git a/cmd/cql-observer/main.go b/cmd/cql-observer/main.go
deleted file mode 100644
index 841d7a991..000000000
--- a/cmd/cql-observer/main.go
+++ /dev/null
@@ -1,101 +0,0 @@
-/*
- * Copyright 2018 The CovenantSQL Authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package main
-
-import (
-	"flag"
-	"fmt"
-	"math/rand"
-	"os"
-	"os/signal"
-	"runtime"
-	"syscall"
-	"time"
-
-	"github.com/CovenantSQL/CovenantSQL/conf"
-	"github.com/CovenantSQL/CovenantSQL/crypto/asymmetric"
-	"github.com/CovenantSQL/CovenantSQL/crypto/kms"
-	"github.com/CovenantSQL/CovenantSQL/sqlchain/observer"
-	"github.com/CovenantSQL/CovenantSQL/utils"
-	"github.com/CovenantSQL/CovenantSQL/utils/log"
-)
-
-const name = "cql-observer"
-
-var (
-	version = "unknown"
-
-	// config
-	configFile  string
-	listenAddr  string
-	showVersion bool
-	logLevel    string
-)
-
-func init() {
-	flag.StringVar(&configFile, "config", "~/.cql/config.yaml", "Config file path")
-	flag.BoolVar(&showVersion, "version", false, "Show version information and exit")
-	flag.BoolVar(&asymmetric.BypassSignature, "bypass-signature", false,
-		"Disable signature sign and verify, for testing")
-	flag.StringVar(&listenAddr, "listen", "127.0.0.1:4663", "Listen address for http explorer api")
-	flag.StringVar(&logLevel, "log-level", "", "Service log level")
-}
-
-func main() {
-	flag.Parse()
-	// set random
-	rand.Seed(time.Now().UnixNano())
-	log.SetStringLevel(logLevel, log.InfoLevel)
-	if showVersion {
-		fmt.Printf("%v %v %v %v %v\n",
-			name, version, runtime.GOOS, runtime.GOARCH, runtime.Version())
-		os.Exit(0)
-	}
-
-	signalCh := make(chan os.Signal, 1)
-	signal.Notify(
-		signalCh,
-		syscall.SIGINT,
-		syscall.SIGTERM,
-	)
-	signal.Ignore(syscall.SIGHUP, syscall.SIGTTIN, syscall.SIGTTOU)
-
-	configFile = utils.HomeDirExpand(configFile)
-
-	flag.Visit(func(f *flag.Flag) {
-		log.Infof("args %#v : %s", f.Name, f.Value)
-	})
-
-	var err error
-	conf.GConf, err = conf.LoadConfig(configFile)
-	if err != nil {
-		log.WithField("config", configFile).WithError(err).Fatal("load config failed")
-	}
-	kms.InitBP()
-
-	service, httpServer, err := observer.StartObserver(listenAddr, version)
-	if err != nil {
-		log.WithError(err).Fatal("start observer failed")
-	}
-
-	<-signalCh
-
-	_ = observer.StopObserver(service, httpServer)
-	log.Info("observer stopped")
-
-	return
-}
diff --git a/sqlchain/observer/node.go b/cmd/cql-observer/node.go
similarity index 95%
rename from sqlchain/observer/node.go
rename to cmd/cql-observer/node.go
index 369d4fb77..c49738de7 100644
--- a/sqlchain/observer/node.go
+++ b/cmd/cql-observer/node.go
@@ -1,5 +1,5 @@
 /*
- * Copyright 2018 The CovenantSQL Authors.
+ * Copyright 2019 The CovenantSQL Authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package observer
+package main
 
 import (
 	"fmt"
diff --git a/cmd/cql-utils/confgen.go b/cmd/cql-utils/confgen.go
index 89d0b80fc..7ab72d514 100644
--- a/cmd/cql-utils/confgen.go
+++ b/cmd/cql-utils/confgen.go
@@ -17,13 +17,11 @@
 package main
 
 import (
-	"bufio"
 	"flag"
 	"fmt"
 	"io/ioutil"
 	"os"
 	"path"
-	"strings"
 
 	yaml "gopkg.in/yaml.v2"
 
@@ -52,26 +50,7 @@ func runConfgen() {
 	publicKeystoreFileName := "public.keystore"
 	privateKeyFile = path.Join(workingRoot, privateKeyFileName)
 
-	if _, err := os.Stat(workingRoot); err == nil {
-		reader := bufio.NewReader(os.Stdin)
-		fmt.Printf("The directory \"%s\" already exists. \nDo you want to delete it? (y or n, press Enter for default n):\n",
-			workingRoot)
-		t, err := reader.ReadString('\n')
-		t = strings.Trim(t, "\n")
-		if err != nil {
-			log.WithError(err).Error("unexpected error")
-			os.Exit(1)
-		}
-		if strings.Compare(t, "y") == 0 || strings.Compare(t, "yes") == 0 {
-			err = os.RemoveAll(workingRoot)
-			if err != nil {
-				log.WithError(err).Error("unexpected error")
-				os.Exit(1)
-			}
-		} else {
-			os.Exit(0)
-		}
-	}
+	askDeletePath(workingRoot)
 
 	err := os.Mkdir(workingRoot, 0755)
 	if err != nil {
@@ -80,7 +59,7 @@ func runConfgen() {
 	}
 
 	fmt.Println("Generating key pair...")
-	publicKey := runKeygen()
+	publicKey := runKeygen(privateKeyFile)
 	fmt.Println("Generated key pair.")
 
 	fmt.Println("Generating nonce...")
diff --git a/cmd/cql-utils/idminer.go b/cmd/cql-utils/idminer.go
index b99da343d..caa526434 100644
--- a/cmd/cql-utils/idminer.go
+++ b/cmd/cql-utils/idminer.go
@@ -23,15 +23,14 @@ import (
 	"math"
 	"math/rand"
 	"os"
-	"os/signal"
 	"runtime"
-	"syscall"
 	"time"
 
 	"github.com/CovenantSQL/CovenantSQL/crypto/asymmetric"
 	"github.com/CovenantSQL/CovenantSQL/crypto/kms"
 	mine "github.com/CovenantSQL/CovenantSQL/pow/cpuminer"
 	"github.com/CovenantSQL/CovenantSQL/proto"
+	"github.com/CovenantSQL/CovenantSQL/utils"
 	"github.com/CovenantSQL/CovenantSQL/utils/log"
 )
 
@@ -69,14 +68,6 @@ func runMiner() {
 		publicKey = privateKey.PubKey()
 	}
 
-	signalCh := make(chan os.Signal, 1)
-	signal.Notify(
-		signalCh,
-		syscall.SIGINT,
-		syscall.SIGTERM,
-	)
-	signal.Ignore(syscall.SIGHUP, syscall.SIGTTIN, syscall.SIGTTOU)
-
 	cpuCount := runtime.NumCPU()
 	log.Infof("cpu: %#v\n", cpuCount)
 	nonceChs := make([]chan mine.NonceInfo, cpuCount)
@@ -102,7 +93,7 @@ func runMiner() {
 		}(i)
 	}
 
-	sig := <-signalCh
+	sig := <-utils.WaitForExit()
 	log.Infof("received signal %#v\n", sig)
 	for i := 0; i < cpuCount; i++ {
 		close(stopChs[i])
diff --git a/cmd/cql-utils/keygen.go b/cmd/cql-utils/keygen.go
index e1541541f..adbb4a6c1 100644
--- a/cmd/cql-utils/keygen.go
+++ b/cmd/cql-utils/keygen.go
@@ -17,54 +17,33 @@
 package main
 
 import (
-	"bufio"
 	"encoding/hex"
 	"fmt"
-	"os"
-	"strings"
 
 	"github.com/CovenantSQL/CovenantSQL/crypto/asymmetric"
 	"github.com/CovenantSQL/CovenantSQL/crypto/kms"
 	"github.com/CovenantSQL/CovenantSQL/utils/log"
 )
 
-func runKeygen() *asymmetric.PublicKey {
-	if _, err := os.Stat(privateKeyFile); err == nil {
-		reader := bufio.NewReader(os.Stdin)
-		fmt.Printf("Private key file \"%s\" already exists. \nDo you want to delete it? (y or n, press Enter for default n):\n",
-			privateKeyFile)
-		t, err := reader.ReadString('\n')
-		t = strings.Trim(t, "\n")
-		if err != nil {
-			log.WithError(err).Error("unexpected error")
-			os.Exit(1)
-		}
-		if strings.Compare(t, "y") == 0 || strings.Compare(t, "yes") == 0 {
-			err = os.Remove(privateKeyFile)
-			if err != nil {
-				log.WithError(err).Error("unexpected error")
-				os.Exit(1)
-			}
-		} else {
-			os.Exit(0)
-		}
-	}
+func runKeygen(privateKeyPath string) *asymmetric.PublicKey {
 
-	privateKey, _, err := asymmetric.GenSecp256k1KeyPair()
-	if err != nil {
-		log.WithError(err).Fatal("generate key pair failed")
-	}
+	askDeletePath(privateKeyPath)
 
 	masterKey, err := readMasterKey()
 	if err != nil {
 		log.WithError(err).Fatal("read master key failed")
 	}
 
-	if err = kms.SavePrivateKey(privateKeyFile, privateKey, []byte(masterKey)); err != nil {
+	privateKey, _, err := asymmetric.GenSecp256k1KeyPair()
+	if err != nil {
+		log.WithError(err).Fatal("generate key pair failed")
+	}
+
+	if err = kms.SavePrivateKey(privateKeyPath, privateKey, []byte(masterKey)); err != nil {
 		log.WithError(err).Fatal("save generated keypair failed")
 	}
 
-	fmt.Printf("Private key file: %s\n", privateKeyFile)
+	fmt.Printf("Private key file: %s\n", privateKeyPath)
 	fmt.Printf("Public key's hex: %s\n", hex.EncodeToString(privateKey.PubKey().Serialize()))
 	return privateKey.PubKey()
 }
diff --git a/cmd/cql-utils/main.go b/cmd/cql-utils/main.go
index 34d6c532d..7a7d8210d 100644
--- a/cmd/cql-utils/main.go
+++ b/cmd/cql-utils/main.go
@@ -17,10 +17,12 @@
 package main
 
 import (
+	"bufio"
 	"flag"
 	"fmt"
 	"os"
 	"runtime"
+	"strings"
 	"syscall"
 
 	"golang.org/x/crypto/ssh/terminal"
@@ -114,3 +116,26 @@ func readMasterKey() (string, error) {
 	fmt.Println()
 	return string(bytePwd), err
 }
+
+func askDeletePath(path string) {
+	if _, err := os.Stat(path); err == nil {
+		reader := bufio.NewReader(os.Stdin)
+		fmt.Printf("\"%s\" already exists. \nDo you want to delete it? (y or n, press Enter for default n):\n",
+			path)
+		t, err := reader.ReadString('\n')
+		t = strings.Trim(t, "\n")
+		if err != nil {
+			log.WithError(err).Error("unexpected error")
+			os.Exit(1)
+		}
+		if strings.Compare(t, "y") == 0 || strings.Compare(t, "yes") == 0 {
+			err = os.RemoveAll(path)
+			if err != nil {
+				log.WithError(err).Error("unexpected error")
+				os.Exit(1)
+			}
+		} else {
+			os.Exit(0)
+		}
+	}
+}
diff --git a/cmd/cql/main.go b/cmd/cql/main.go
index 807e6f4ff..de31d6109 100644
--- a/cmd/cql/main.go
+++ b/cmd/cql/main.go
@@ -51,6 +51,7 @@ import (
 	"github.com/CovenantSQL/CovenantSQL/crypto/asymmetric"
 	"github.com/CovenantSQL/CovenantSQL/crypto/hash"
 	"github.com/CovenantSQL/CovenantSQL/proto"
+	"github.com/CovenantSQL/CovenantSQL/sqlchain/adapter"
 	"github.com/CovenantSQL/CovenantSQL/sqlchain/observer"
 	"github.com/CovenantSQL/CovenantSQL/types"
 	"github.com/CovenantSQL/CovenantSQL/utils"
@@ -71,14 +72,14 @@ var (
 	singleTransaction bool
 	showVersion       bool
 	variables         varsFlag
-	stopCh            = make(chan struct{})
 	logLevel          string
 
-	// Shard chain explorer stuff
+	// Shard chain explorer/adapter stuff
 	tmpPath      string         // background observer and explorer block and log file path
 	cLog         *logrus.Logger // console logger
 	bgLogLevel   string         // background log level
 	explorerAddr string         // explorer Web addr
+	adapterAddr  string         // adapter listen addr
 
 	// DML variables
 	createDB                string // as a instance meta json string or simply a node count
@@ -251,6 +252,7 @@ func init() {
 	flag.StringVar(&tmpPath, "tmp-path", "", "Explorer temp file path, use os.TempDir for default")
 	flag.StringVar(&bgLogLevel, "bg-log-level", "", "Background service log level")
 	flag.StringVar(&explorerAddr, "web", "", "Address to serve a database chain explorer, e.g. :8546")
+	flag.StringVar(&adapterAddr, "adapter", "", "Address to serve a database chain adapter, e.g. :7784")
 
 	// DML flags
 	flag.StringVar(&createDB, "create", "", "Create database, argument can be instance requirement json or simply a node count requirement")
@@ -272,7 +274,7 @@ func main() {
 	if tmpPath == "" {
 		tmpPath = os.TempDir()
 	}
-	logPath := filepath.Join(tmpPath, "covenant_explorer.log")
+	logPath := filepath.Join(tmpPath, "covenant_service.log")
 	bgLog, err := os.OpenFile(logPath, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "open log file failed: %s, %v", logPath, err)
@@ -292,13 +294,14 @@ func main() {
 
 	configFile = utils.HomeDirExpand(configFile)
 
-	if explorerAddr != "" {
-		var err error
-		conf.GConf, err = conf.LoadConfig(configFile)
-		if err != nil {
-			log.WithField("config", configFile).WithError(err).Fatal("load config failed")
-		}
+	// init covenantsql driver
+	if err = client.Init(configFile, []byte(password)); err != nil {
+		cLog.WithError(err).Error("init covenantsql client failed")
+		os.Exit(-1)
+		return
+	}
 
+	if explorerAddr != "" {
 		service, httpServer, err = observer.StartObserver(explorerAddr, version)
 		if err != nil {
 			log.WithError(err).Fatal("start explorer failed")
@@ -306,18 +309,29 @@ func main() {
 			cLog.Infof("explorer started on %s", explorerAddr)
 		}
 
-		defer close(stopCh)
-		go func() {
-			<-stopCh
+		defer func() {
 			_ = observer.StopObserver(service, httpServer)
 			log.Info("explorer stopped")
 		}()
-	} else {
-		// init covenantsql driver
-		if err = client.Init(configFile, []byte(password)); err != nil {
-			cLog.WithError(err).Error("init covenantsql client failed")
-			os.Exit(-1)
-			return
+	}
+
+	if adapterAddr != "" {
+		server, err := adapter.NewHTTPAdapter(adapterAddr, configFile)
+		if err != nil {
+			log.WithError(err).Fatal("init adapter failed")
+		}
+
+		if err = server.Serve(); err != nil {
+			log.WithError(err).Fatal("start adapter failed")
+		} else {
+			cLog.Infof("adapter started on %s", adapterAddr)
+
+			defer func() {
+				ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
+				defer cancel()
+				server.Shutdown(ctx)
+				log.Info("stopped adapter")
+			}()
 		}
 	}
 
@@ -584,6 +598,13 @@ func main() {
 		os.Exit(-1)
 		return
 	}
+
+	// if web flag is enabled
+	if explorerAddr != "" || adapterAddr != "" {
+		fmt.Printf("Ctrl + C to stop explorer on %s and adapter on %s", explorerAddr, adapterAddr)
+		<-utils.WaitForExit()
+		return
+	}
 }
 
 func wait(txHash hash.Hash) (err error) {
diff --git a/cmd/cql-observer/main_test.go b/cmd/cql/main_test.go
similarity index 100%
rename from cmd/cql-observer/main_test.go
rename to cmd/cql/main_test.go
diff --git a/cmd/cqld/bootstrap.go b/cmd/cqld/bootstrap.go
index f77e51a82..7092445b3 100644
--- a/cmd/cqld/bootstrap.go
+++ b/cmd/cqld/bootstrap.go
@@ -18,8 +18,6 @@ package main
 
 import (
 	"fmt"
-	"os"
-	"os/signal"
 	"syscall"
 	"time"
 
@@ -34,12 +32,12 @@ import (
 	"github.com/CovenantSQL/CovenantSQL/route"
 	"github.com/CovenantSQL/CovenantSQL/rpc"
 	"github.com/CovenantSQL/CovenantSQL/types"
+	"github.com/CovenantSQL/CovenantSQL/utils"
 	"github.com/CovenantSQL/CovenantSQL/utils/log"
 )
 
 const (
-	dhtGossipServiceName = "DHTG"
-	dhtGossipTimeout     = time.Second * 20
+	dhtGossipTimeout = time.Second * 20
 )
 
 func runNode(nodeID proto.NodeID, listenAddr string) (err error) {
@@ -177,15 +175,7 @@ func runNode(nodeID proto.NodeID, listenAddr string) (err error) {
 		}()
 	}
 
-	signalCh := make(chan os.Signal, 1)
-	signal.Notify(
-		signalCh,
-		syscall.SIGINT,
-		syscall.SIGTERM,
-	)
-	signal.Ignore(syscall.SIGHUP, syscall.SIGTTIN, syscall.SIGTTOU)
-
-	<-signalCh
+	<-utils.WaitForExit()
 	return
 }
 
diff --git a/cmd/cqld/main.go b/cmd/cqld/main.go
index 00e7fd1bb..f69ee9594 100644
--- a/cmd/cqld/main.go
+++ b/cmd/cqld/main.go
@@ -31,6 +31,7 @@ import (
 	"github.com/CovenantSQL/CovenantSQL/metric"
 	"github.com/CovenantSQL/CovenantSQL/utils"
 	"github.com/CovenantSQL/CovenantSQL/utils/log"
+	_ "github.com/CovenantSQL/CovenantSQL/utils/log/debug"
 )
 
 const logo = `
diff --git a/codecov.yml b/codecov.yml
index 5027ce7f9..2db6258a6 100644
--- a/codecov.yml
+++ b/codecov.yml
@@ -31,6 +31,7 @@ ignore:
   - "vendor"
   - "cmd"
   - "sqlchain/observer"
+  - "sqlchain/adapter"
   - "test"
   - "crypto/secp256k1"
   - "_example/**/*"
diff --git a/docker-compose.yml b/docker-compose.yml
index 7117c291c..a9d54e6f5 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -136,9 +136,8 @@ services:
     environment:
       COVENANT_ROLE: adapter
       COVENANT_CONF: ./node_adapter/config.yaml
+      COVENANTSQL_ADAPTER_ADDR: 0.0.0.0:4661
     volumes:
-      - ./test/service/node_adapter/config.yaml:/app/config.yaml
-      - ./test/service/node_adapter/private.key:/app/private.key
       - ./test/service/node_adapter/:/app/node_adapter/
     networks:
       default:
@@ -164,7 +163,7 @@ services:
         max-size: '1m'
         max-file: '10'
   covenantsql_observer:
-    image: covenantsql/covenantsql-observer:latest
+    image: covenantsql/covenantsql:latest
     container_name: covenantsql_observer
     restart: always
     ports:
@@ -172,7 +171,6 @@ services:
     environment:
       COVENANT_ROLE: observer
       COVENANT_CONF: ./node_observer/config.yaml
-      COVENANTSQL_EXPLORER_DOMAIN: localhost
       COVENANTSQL_OBSERVER_ADDR: localhost:4663
     volumes:
       - ./test/service/node_observer/:/app/node_observer/
diff --git a/docker/observer.Dockerfile b/docker/observer.Dockerfile
deleted file mode 100644
index d0c485796..000000000
--- a/docker/observer.Dockerfile
+++ /dev/null
@@ -1,28 +0,0 @@
-# Stage: observer
-FROM covenantsql/explorer
-
-ARG COMMIT
-ARG VERSION
-
-LABEL \
-    name="covenantsql_observer" \
-    homepage="https://github.com/CovenantSQL/CovenantSQL.git" \
-    maintainer="jin.xu@covenantsql.io" \
-    authors="CovenantSQL Team" \
-    commit="${COMMIT}" \
-    version="${VERSION}"
-
-ENV VERSION=${VERSION}
-ENV COVENANT_ROLE=observer
-ENV COVENANT_CONF=config.yaml
-
-RUN apk --no-cache add ca-certificates
-
-WORKDIR /app
-COPY --from=covenantsql/covenantsql-builder /go/src/github.com/CovenantSQL/CovenantSQL/bin/cql-observer /app/
-COPY --from=covenantsql/covenantsql-builder /go/src/github.com/CovenantSQL/CovenantSQL/bin/cql /app/
-COPY --from=covenantsql/covenantsql-builder /go/src/github.com/CovenantSQL/CovenantSQL/bin/cql-utils /app/
-COPY --from=covenantsql/covenantsql-builder /go/src/github.com/CovenantSQL/CovenantSQL/bin/docker-entry.sh /app/
-ENTRYPOINT [ "./docker-entry.sh" ]
-EXPOSE 4661
-EXPOSE 80
diff --git a/metric/loadavg_unix.go b/metric/loadavg_unix.go
index 16bda06db..ea3b76836 100644
--- a/metric/loadavg_unix.go
+++ b/metric/loadavg_unix.go
@@ -20,7 +20,7 @@ import (
 	"errors"
 )
 
-// #include <stdlib.h>.
+// #include <stdlib.h>
 import "C"
 
 func getLoad() ([]float64, error) {
diff --git a/metric/meminfo_darwin.go b/metric/meminfo_darwin.go
index 2e85a61f0..121479495 100644
--- a/metric/meminfo_darwin.go
+++ b/metric/meminfo_darwin.go
@@ -2,7 +2,7 @@
 
 package metric
 
-// #include <mach/mach_host.h>.
+// #include <mach/mach_host.h>
 import "C"
 
 import (
diff --git a/cmd/cql-adapter/README.md b/sqlchain/adapter/README.md
similarity index 100%
rename from cmd/cql-adapter/README.md
rename to sqlchain/adapter/README.md
diff --git a/cmd/cql-adapter/api/account.go b/sqlchain/adapter/api/account.go
similarity index 100%
rename from cmd/cql-adapter/api/account.go
rename to sqlchain/adapter/api/account.go
diff --git a/cmd/cql-adapter/api/admin.go b/sqlchain/adapter/api/admin.go
similarity index 98%
rename from cmd/cql-adapter/api/admin.go
rename to sqlchain/adapter/api/admin.go
index 55eb4ef79..c367799ea 100644
--- a/cmd/cql-adapter/api/admin.go
+++ b/sqlchain/adapter/api/admin.go
@@ -22,7 +22,7 @@ import (
 	"net/http"
 	"strconv"
 
-	"github.com/CovenantSQL/CovenantSQL/cmd/cql-adapter/config"
+	"github.com/CovenantSQL/CovenantSQL/sqlchain/adapter/config"
 	"github.com/CovenantSQL/CovenantSQL/utils/log"
 )
 
diff --git a/cmd/cql-adapter/api/doc.go b/sqlchain/adapter/api/doc.go
similarity index 100%
rename from cmd/cql-adapter/api/doc.go
rename to sqlchain/adapter/api/doc.go
diff --git a/cmd/cql-adapter/api/query.go b/sqlchain/adapter/api/query.go
similarity index 98%
rename from cmd/cql-adapter/api/query.go
rename to sqlchain/adapter/api/query.go
index 1142e4bf2..0b865718c 100644
--- a/cmd/cql-adapter/api/query.go
+++ b/sqlchain/adapter/api/query.go
@@ -20,7 +20,7 @@ import (
 	"fmt"
 	"net/http"
 
-	"github.com/CovenantSQL/CovenantSQL/cmd/cql-adapter/config"
+	"github.com/CovenantSQL/CovenantSQL/sqlchain/adapter/config"
 	"github.com/CovenantSQL/CovenantSQL/utils/log"
 )
 
diff --git a/cmd/cql-adapter/api/router.go b/sqlchain/adapter/api/router.go
similarity index 100%
rename from cmd/cql-adapter/api/router.go
rename to sqlchain/adapter/api/router.go
diff --git a/cmd/cql-adapter/api/utils.go b/sqlchain/adapter/api/utils.go
similarity index 100%
rename from cmd/cql-adapter/api/utils.go
rename to sqlchain/adapter/api/utils.go
diff --git a/cmd/cql-adapter/config/config.go b/sqlchain/adapter/config/config.go
similarity index 93%
rename from cmd/cql-adapter/config/config.go
rename to sqlchain/adapter/config/config.go
index ba2ed392d..8a89bcdb7 100644
--- a/cmd/cql-adapter/config/config.go
+++ b/sqlchain/adapter/config/config.go
@@ -27,9 +27,8 @@ import (
 
 	yaml "gopkg.in/yaml.v2"
 
-	"github.com/CovenantSQL/CovenantSQL/client"
-	"github.com/CovenantSQL/CovenantSQL/cmd/cql-adapter/storage"
 	"github.com/CovenantSQL/CovenantSQL/conf"
+	"github.com/CovenantSQL/CovenantSQL/sqlchain/adapter/storage"
 	"github.com/CovenantSQL/CovenantSQL/utils/log"
 )
 
@@ -69,8 +68,9 @@ type confWrapper struct {
 	Adapter Config `yaml:"Adapter"`
 }
 
-// LoadConfig load and verify config in config file and set to global config instance.
-func LoadConfig(configPath string, password string) (config *Config, err error) {
+// LoadConfig load and verify config in config file (Reuse some global config instance values).
+// Should call conf.LoadConfig before use. e.g client.Init
+func LoadConfig(configPath string) (config *Config, err error) {
 	var workingRoot string
 	var configBytes []byte
 	if configBytes, err = ioutil.ReadFile(configPath); err != nil {
@@ -88,10 +88,6 @@ func LoadConfig(configPath string, password string) (config *Config, err error)
 		config.StorageDriver = "covenantsql"
 	}
 	if config.StorageDriver == "covenantsql" {
-		// init client
-		if err = client.Init(configPath, []byte(password)); err != nil {
-			return
-		}
 		workingRoot = conf.GConf.WorkingRoot
 	} else {
 		if workingRoot, err = os.Getwd(); err != nil {
diff --git a/cmd/cql-adapter/config/doc.go b/sqlchain/adapter/config/doc.go
similarity index 100%
rename from cmd/cql-adapter/config/doc.go
rename to sqlchain/adapter/config/doc.go
diff --git a/cmd/cql-adapter/config/errors.go b/sqlchain/adapter/config/errors.go
similarity index 100%
rename from cmd/cql-adapter/config/errors.go
rename to sqlchain/adapter/config/errors.go
diff --git a/cmd/cql-adapter/server.go b/sqlchain/adapter/server.go
similarity index 85%
rename from cmd/cql-adapter/server.go
rename to sqlchain/adapter/server.go
index 4fb17af78..de1fb533f 100644
--- a/cmd/cql-adapter/server.go
+++ b/sqlchain/adapter/server.go
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package main
+package adapter
 
 import (
 	"context"
@@ -24,8 +24,8 @@ import (
 
 	"github.com/gorilla/handlers"
 
-	"github.com/CovenantSQL/CovenantSQL/cmd/cql-adapter/api"
-	"github.com/CovenantSQL/CovenantSQL/cmd/cql-adapter/config"
+	"github.com/CovenantSQL/CovenantSQL/sqlchain/adapter/api"
+	"github.com/CovenantSQL/CovenantSQL/sqlchain/adapter/config"
 )
 
 // HTTPAdapter is a adapter for covenantsql/alternative sqlite3 service.
@@ -34,12 +34,12 @@ type HTTPAdapter struct {
 }
 
 // NewHTTPAdapter creates adapter to service.
-func NewHTTPAdapter(listenAddr string, configFile string, password string) (adapter *HTTPAdapter, err error) {
+func NewHTTPAdapter(listenAddr string, configFile string) (adapter *HTTPAdapter, err error) {
 	adapter = new(HTTPAdapter)
 
 	// load config file
 	var cfg *config.Config
-	if cfg, err = config.LoadConfig(configFile, password); err != nil {
+	if cfg, err = config.LoadConfig(configFile); err != nil {
 		return
 	}
 
diff --git a/cmd/cql-adapter/storage/covenantsql.go b/sqlchain/adapter/storage/covenantsql.go
similarity index 100%
rename from cmd/cql-adapter/storage/covenantsql.go
rename to sqlchain/adapter/storage/covenantsql.go
diff --git a/cmd/cql-adapter/storage/doc.go b/sqlchain/adapter/storage/doc.go
similarity index 100%
rename from cmd/cql-adapter/storage/doc.go
rename to sqlchain/adapter/storage/doc.go
diff --git a/cmd/cql-adapter/storage/sqlite3.go b/sqlchain/adapter/storage/sqlite3.go
similarity index 100%
rename from cmd/cql-adapter/storage/sqlite3.go
rename to sqlchain/adapter/storage/sqlite3.go
diff --git a/cmd/cql-adapter/storage/storage.go b/sqlchain/adapter/storage/storage.go
similarity index 100%
rename from cmd/cql-adapter/storage/storage.go
rename to sqlchain/adapter/storage/storage.go
diff --git a/sqlchain/observer/api.go b/sqlchain/observer/api.go
index 2e7cf426f..cc20e7eb8 100644
--- a/sqlchain/observer/api.go
+++ b/sqlchain/observer/api.go
@@ -26,6 +26,7 @@ import (
 	"strconv"
 	"time"
 
+	"github.com/gorilla/handlers"
 	"github.com/gorilla/mux"
 	"github.com/rakyll/statik/fs"
 
@@ -668,15 +669,15 @@ func startAPI(service *Service, listenAddr string, version string) (server *http
 	}
 
 	router := mux.NewRouter()
-	fs := http.FileServer(statikFS)
-	router.Handle("/", fs)
-	router.Handle("/static/{type}/{file}", fs)
+	fsh := http.FileServer(statikFS)
+	router.Handle("/", fsh)
+	router.Handle("/static/{type}/{file}", fsh)
 	router.PathPrefix("/dbs").HandlerFunc(func(writer http.ResponseWriter, request *http.Request) {
 		r2 := new(http.Request)
 		*r2 = *request
 		r2.URL = new(url.URL)
 		r2.URL.Path = "/"
-		fs.ServeHTTP(writer, r2)
+		fsh.ServeHTTP(writer, r2)
 	})
 	router.HandleFunc("/version", func(rw http.ResponseWriter, r *http.Request) {
 		sendResponse(http.StatusOK, true, nil, map[string]interface{}{
@@ -714,7 +715,7 @@ func startAPI(service *Service, listenAddr string, version string) (server *http
 		WriteTimeout: apiTimeout * 10,
 		ReadTimeout:  apiTimeout,
 		IdleTimeout:  apiTimeout,
-		Handler:      router,
+		Handler:      handlers.CORS()(router),
 	}
 
 	go func() {
diff --git a/sqlchain/observer/observation_test.go b/sqlchain/observer/observation_test.go
index f7743f0ae..f9a95ab31 100644
--- a/sqlchain/observer/observation_test.go
+++ b/sqlchain/observer/observation_test.go
@@ -91,7 +91,7 @@ func startNodes() {
 	if cmd, err = utils.RunCommandNB(
 		FJ(baseDir, "./bin/cqld.test"),
 		[]string{"-config", FJ(testWorkingDir, "./observation/node_0/config.yaml"),
-			"-test.coverprofile", FJ(baseDir, "./cmd/cql-observer/leader.cover.out"),
+			"-test.coverprofile", FJ(baseDir, "./cmd/cql/leader.cover.out"),
 		},
 		"leader", testWorkingDir, logDir, false,
 	); err == nil {
@@ -102,7 +102,7 @@ func startNodes() {
 	if cmd, err = utils.RunCommandNB(
 		FJ(baseDir, "./bin/cqld.test"),
 		[]string{"-config", FJ(testWorkingDir, "./observation/node_1/config.yaml"),
-			"-test.coverprofile", FJ(baseDir, "./cmd/cql-observer/follower1.cover.out"),
+			"-test.coverprofile", FJ(baseDir, "./cmd/cql/follower1.cover.out"),
 		},
 		"follower1", testWorkingDir, logDir, false,
 	); err == nil {
@@ -113,7 +113,7 @@ func startNodes() {
 	if cmd, err = utils.RunCommandNB(
 		FJ(baseDir, "./bin/cqld.test"),
 		[]string{"-config", FJ(testWorkingDir, "./observation/node_2/config.yaml"),
-			"-test.coverprofile", FJ(baseDir, "./cmd/cql-observer/follower2.cover.out"),
+			"-test.coverprofile", FJ(baseDir, "./cmd/cql/follower2.cover.out"),
 		},
 		"follower2", testWorkingDir, logDir, false,
 	); err == nil {
@@ -150,7 +150,7 @@ func startNodes() {
 	if cmd, err = utils.RunCommandNB(
 		FJ(baseDir, "./bin/cql-minerd.test"),
 		[]string{"-config", FJ(testWorkingDir, "./observation/node_miner_0/config.yaml"),
-			"-test.coverprofile", FJ(baseDir, "./cmd/cql-observer/miner0.cover.out"),
+			"-test.coverprofile", FJ(baseDir, "./cmd/cql/miner0.cover.out"),
 		},
 		"miner0", testWorkingDir, logDir, false,
 	); err == nil {
@@ -163,7 +163,7 @@ func startNodes() {
 	if cmd, err = utils.RunCommandNB(
 		FJ(baseDir, "./bin/cql-minerd.test"),
 		[]string{"-config", FJ(testWorkingDir, "./observation/node_miner_1/config.yaml"),
-			"-test.coverprofile", FJ(baseDir, "./cmd/cql-observer/miner1.cover.out"),
+			"-test.coverprofile", FJ(baseDir, "./cmd/cql/miner1.cover.out"),
 		},
 		"miner1", testWorkingDir, logDir, false,
 	); err == nil {
@@ -176,7 +176,7 @@ func startNodes() {
 	if cmd, err = utils.RunCommandNB(
 		FJ(baseDir, "./bin/cql-minerd.test"),
 		[]string{"-config", FJ(testWorkingDir, "./observation/node_miner_2/config.yaml"),
-			"-test.coverprofile", FJ(baseDir, "./cmd/cql-observer/miner2.cover.out"),
+			"-test.coverprofile", FJ(baseDir, "./cmd/cql/miner2.cover.out"),
 		},
 		"miner2", testWorkingDir, logDir, false,
 	); err == nil {
@@ -487,10 +487,11 @@ func TestFullProcess(t *testing.T) {
 
 		var observerCmd *utils.CMD
 		observerCmd, err = utils.RunCommandNB(
-			FJ(baseDir, "./bin/cql-observer.test"),
+			FJ(baseDir, "./bin/cql.test"),
 			[]string{"-config", FJ(testWorkingDir, "./observation/node_observer/config.yaml"),
-				"-log-level", "debug",
-				"-test.coverprofile", FJ(baseDir, "./cmd/cql-observer/observer.cover.out"),
+				"-bg-log-level", "debug",
+				"-test.coverprofile", FJ(baseDir, "./cmd/cql/observer.cover.out"),
+				"-web", "127.0.0.1:4663",
 			},
 			"observer", testWorkingDir, logDir, false,
 		)
@@ -717,9 +718,11 @@ func TestFullProcess(t *testing.T) {
 
 		// start observer again
 		observerCmd, err = utils.RunCommandNB(
-			FJ(baseDir, "./bin/cql-observer.test"),
+			FJ(baseDir, "./bin/cql.test"),
 			[]string{"-config", FJ(testWorkingDir, "./observation/node_observer/config.yaml"),
-				"-test.coverprofile", FJ(baseDir, "./cmd/cql-observer/observer.cover.out"),
+				"-bg-log-level", "debug",
+				"-test.coverprofile", FJ(baseDir, "./cmd/cql/observer.cover.out"),
+				"-web", "127.0.0.1:4663",
 			},
 			"observer", testWorkingDir, logDir, false,
 		)
diff --git a/sqlchain/observer/observer.go b/sqlchain/observer/observer.go
index bfde4ad9e..79de69f61 100644
--- a/sqlchain/observer/observer.go
+++ b/sqlchain/observer/observer.go
@@ -63,11 +63,6 @@ func stopService(service *Service) (err error) {
 
 // StartObserver starts the observer service and http API server.
 func StartObserver(listenAddr string, version string) (service *Service, httpServer *http.Server, err error) {
-	// init node
-	if err = initNode(); err != nil {
-		log.WithError(err).Fatal("init node failed")
-	}
-
 	// start service
 	if service, err = startService(); err != nil {
 		log.WithError(err).Fatal("start observation failed")
diff --git a/sqlchain/observer/service.go b/sqlchain/observer/service.go
index 6713000b6..7bf244360 100644
--- a/sqlchain/observer/service.go
+++ b/sqlchain/observer/service.go
@@ -306,6 +306,13 @@ func (s *Service) addQueryTracker(dbID proto.DatabaseID, height int32, offset in
 
 func (s *Service) addBlock(dbID proto.DatabaseID, count int32, b *types.Block) (err error) {
 	instance, err := s.getUpstream(dbID)
+	if err != nil {
+		return
+	}
+	if b == nil {
+		return
+	}
+
 	h := int32(b.Timestamp().Sub(instance.GenesisBlock.Timestamp()) / conf.GConf.SQLChainPeriod)
 	key := utils.ConcatAll(int32ToBytes(h), b.BlockHash().AsBytes(), int32ToBytes(count))
 	// It's actually `countToBytes`
diff --git a/test/compatibility/node_0/config.yaml b/test/compatibility/node_0/config.yaml
new file mode 100644
index 000000000..cd1a54cda
--- /dev/null
+++ b/test/compatibility/node_0/config.yaml
@@ -0,0 +1,122 @@
+IsTestMode: true
+WorkingRoot: "./"
+PubKeyStoreFile: "public.keystore"
+PrivateKeyFile: "private.key"
+DHTFileName: "dht.db"
+ListenAddr: "127.0.0.1:3122"
+ThisNodeID: "00000bef611d346c0cbe1beaa76e7f0ed705a194fdf9ac3a248ec70e9c198bf9"
+QPS: 1000
+BillingBlockCount: 2
+ChainBusPeriod: 1s
+BPPeriod: 3s
+BPTick: 1s
+SQLChainPeriod: 3s
+SQLChainTick: 1s
+SQLChainTTL: 10
+MinProviderDeposit: 1000000
+ValidDNSKeys:
+  koPbw9wmYZ7ggcjnQ6ayHyhHaDNMYELKTqT+qRGrZpWSccr/lBcrm10Z1PuQHB3Azhii+sb0PYFkH1ruxLhe5g==: cloudflare.com
+  mdsswUyr3DPW132mOi8V9xESWE8jTo0dxCjjnopKl+GqJxpVXckHAeF+KkxLbxILfDLUT0rAK9iUzy1L53eKGQ==: cloudflare.com
+  oJMRESz5E4gYzS/q6XDrvU1qMPYIjCWzJaOau8XNEZeqCYKD5ar0IRd8KqXXFJkqmVfRvMGPmM1x8fGAa2XhSA==: cloudflare.com
+MinNodeIDDifficulty: 2
+DNSSeed:
+  EnforcedDNSSEC: false
+  DNSServers:
+  - 1.1.1.1
+  - 202.46.34.74
+  - 202.46.34.75
+  - 202.46.34.76
+
+BlockProducer:
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  NodeID: 00000bef611d346c0cbe1beaa76e7f0ed705a194fdf9ac3a248ec70e9c198bf9
+  Nonce:
+    a: 313283
+    b: 0
+    c: 0
+    d: 0
+  ChainFileName: "chain.db"
+  BPGenesisInfo:
+    Version: 1
+    BlockHash: f745ca6427237aac858dd3c7f2df8e6f3c18d0f1c164e07a1c6b8eebeba6b154
+    Producer: 0000000000000000000000000000000000000000000000000000000000000001
+    MerkleRoot: 0000000000000000000000000000000000000000000000000000000000000001
+    ParentHash: 0000000000000000000000000000000000000000000000000000000000000001
+    Timestamp: 2018-08-13T21:59:59.12Z
+    BaseAccounts:
+      - Address: ba0ba731c7a76ccef2c1170f42038f7e228dfb474ef0190dfe35d9a37911ed37
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+      - Address: 1a7b0959bbd0d0ec529278a61c0056c277bffe75b2646e1699b46b10a90210be
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+      - Address: 9235bc4130a2ed4e6c35ea189dab35198ebb105640bedb97dd5269cc80863b16
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+      - Address: 9e1618775cceeb19f110e04fbc6c5bca6c8e4e9b116e193a42fe69bf602e7bcd
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+KnownNodes:
+- ID: 00000bef611d346c0cbe1beaa76e7f0ed705a194fdf9ac3a248ec70e9c198bf9
+  Nonce:
+    a: 313283
+    b: 0
+    c: 0
+    d: 0
+  Addr: 127.0.0.1:3122
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  Role: Leader
+- ID: 00000381d46fd6cf7742d7fb94e2422033af989c0e348b5781b3219599a3af35
+  Nonce:
+    a: 478373
+    b: 0
+    c: 0
+    d: 2305843009893772025
+  Addr: 127.0.0.1:3121
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  Role: Follower
+- ID: 000000172580063ded88e010556b0aca2851265be8845b1ef397e8fce6ab5582
+  Nonce:
+    a: 259939
+    b: 0
+    c: 0
+    d: 2305843012544226372
+  Addr: 127.0.0.1:3120
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  Role: Follower
+- ID: 00000f3b43288fe99831eb533ab77ec455d13e11fc38ec35a42d4edd17aa320d
+  Nonce:
+    a: 22403
+    b: 0
+    c: 0
+    d: 0
+  Addr: ""
+  PublicKey: 02ec784ca599f21ef93fe7abdc68d78817ab6c9b31f2324d15ea174d9da498b4c4
+  Role: Client
+- ID: 000005aa62048f85da4ae9698ed59c14ec0d48a88a07c15a32265634e7e64ade
+  Nonce:
+    a: 567323
+    b: 0
+    c: 0
+    d: 3104982049
+  Addr: 127.0.0.1:2144
+  PublicKey: 0367aa51809a7c1dc0f82c02452fec9557b3e1d10ce7c919d8e73d90048df86d20
+  Role: Miner
+- ID: 000005f4f22c06f76c43c4f48d5a7ec1309cc94030cbf9ebae814172884ac8b5
+  Nonce:
+    a: 240524
+    b: 0
+    c: 0
+    d: 2305843010430351476
+  Addr: 127.0.0.1:2145
+  PublicKey: 02914bca0806f040dd842207c44474ab41ecd29deee7f2d355789c5c78d448ca16
+  Role: Miner
+- ID: 000003f49592f83d0473bddb70d543f1096b4ffed5e5f942a3117e256b7052b8
+  Nonce:
+    a: 606016
+    b: 0
+    c: 0
+    d: 13835058056920509601
+  Addr: 127.0.0.1:2146
+  PublicKey: 03ae859eac5b72ee428c7a85f10b2ce748d9de5e480aefbb70f6597dfa8b2175e5
+  Role: Miner
diff --git a/test/compatibility/node_0/private.key b/test/compatibility/node_0/private.key
new file mode 100644
index 000000000..449618c0a
--- /dev/null
+++ b/test/compatibility/node_0/private.key
@@ -0,0 +1,2 @@
+WAð�8��#|�T��Z�ԓ�`�mF�}�~�e��ʆ?�~�����*E��%���v�����p�o*a߂�ç_Bľ@8
+��M�C2�
\ No newline at end of file
diff --git a/test/compatibility/node_1/config.yaml b/test/compatibility/node_1/config.yaml
new file mode 100644
index 000000000..eca03e17d
--- /dev/null
+++ b/test/compatibility/node_1/config.yaml
@@ -0,0 +1,122 @@
+IsTestMode: true
+WorkingRoot: "./"
+PubKeyStoreFile: "public.keystore"
+PrivateKeyFile: "private.key"
+DHTFileName: "dht.db"
+ListenAddr: "127.0.0.1:3121"
+ThisNodeID: "00000381d46fd6cf7742d7fb94e2422033af989c0e348b5781b3219599a3af35"
+QPS: 1000
+BillingBlockCount: 2
+ChainBusPeriod: 1s
+BPPeriod: 3s
+BPTick: 1s
+SQLChainPeriod: 3s
+SQLChainTick: 1s
+SQLChainTTL: 10
+MinProviderDeposit: 1000000
+ValidDNSKeys:
+  koPbw9wmYZ7ggcjnQ6ayHyhHaDNMYELKTqT+qRGrZpWSccr/lBcrm10Z1PuQHB3Azhii+sb0PYFkH1ruxLhe5g==: cloudflare.com
+  mdsswUyr3DPW132mOi8V9xESWE8jTo0dxCjjnopKl+GqJxpVXckHAeF+KkxLbxILfDLUT0rAK9iUzy1L53eKGQ==: cloudflare.com
+  oJMRESz5E4gYzS/q6XDrvU1qMPYIjCWzJaOau8XNEZeqCYKD5ar0IRd8KqXXFJkqmVfRvMGPmM1x8fGAa2XhSA==: cloudflare.com
+MinNodeIDDifficulty: 2
+DNSSeed:
+  EnforcedDNSSEC: false
+  DNSServers:
+  - 1.1.1.1
+  - 202.46.34.74
+  - 202.46.34.75
+  - 202.46.34.76
+
+BlockProducer:
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  NodeID: 00000bef611d346c0cbe1beaa76e7f0ed705a194fdf9ac3a248ec70e9c198bf9
+  Nonce:
+    a: 313283
+    b: 0
+    c: 0
+    d: 0
+  ChainFileName: "chain.db"
+  BPGenesisInfo:
+    Version: 1
+    BlockHash: f745ca6427237aac858dd3c7f2df8e6f3c18d0f1c164e07a1c6b8eebeba6b154
+    Producer: 0000000000000000000000000000000000000000000000000000000000000001
+    MerkleRoot: 0000000000000000000000000000000000000000000000000000000000000001
+    ParentHash: 0000000000000000000000000000000000000000000000000000000000000001
+    Timestamp: 2018-08-13T21:59:59.12Z
+    BaseAccounts:
+      - Address: ba0ba731c7a76ccef2c1170f42038f7e228dfb474ef0190dfe35d9a37911ed37
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+      - Address: 1a7b0959bbd0d0ec529278a61c0056c277bffe75b2646e1699b46b10a90210be
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+      - Address: 9235bc4130a2ed4e6c35ea189dab35198ebb105640bedb97dd5269cc80863b16
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+      - Address: 9e1618775cceeb19f110e04fbc6c5bca6c8e4e9b116e193a42fe69bf602e7bcd
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+KnownNodes:
+- ID: 00000bef611d346c0cbe1beaa76e7f0ed705a194fdf9ac3a248ec70e9c198bf9
+  Nonce:
+    a: 313283
+    b: 0
+    c: 0
+    d: 0
+  Addr: 127.0.0.1:3122
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  Role: Leader
+- ID: 00000381d46fd6cf7742d7fb94e2422033af989c0e348b5781b3219599a3af35
+  Nonce:
+    a: 478373
+    b: 0
+    c: 0
+    d: 2305843009893772025
+  Addr: 127.0.0.1:3121
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  Role: Follower
+- ID: 000000172580063ded88e010556b0aca2851265be8845b1ef397e8fce6ab5582
+  Nonce:
+    a: 259939
+    b: 0
+    c: 0
+    d: 2305843012544226372
+  Addr: 127.0.0.1:3120
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  Role: Follower
+- ID: 00000f3b43288fe99831eb533ab77ec455d13e11fc38ec35a42d4edd17aa320d
+  Nonce:
+    a: 22403
+    b: 0
+    c: 0
+    d: 0
+  Addr: ""
+  PublicKey: 02ec784ca599f21ef93fe7abdc68d78817ab6c9b31f2324d15ea174d9da498b4c4
+  Role: Client
+- ID: 000005aa62048f85da4ae9698ed59c14ec0d48a88a07c15a32265634e7e64ade
+  Nonce:
+    a: 567323
+    b: 0
+    c: 0
+    d: 3104982049
+  Addr: 127.0.0.1:2144
+  PublicKey: 0367aa51809a7c1dc0f82c02452fec9557b3e1d10ce7c919d8e73d90048df86d20
+  Role: Miner
+- ID: 000005f4f22c06f76c43c4f48d5a7ec1309cc94030cbf9ebae814172884ac8b5
+  Nonce:
+    a: 240524
+    b: 0
+    c: 0
+    d: 2305843010430351476
+  Addr: 127.0.0.1:2145
+  PublicKey: 02914bca0806f040dd842207c44474ab41ecd29deee7f2d355789c5c78d448ca16
+  Role: Miner
+- ID: 000003f49592f83d0473bddb70d543f1096b4ffed5e5f942a3117e256b7052b8
+  Nonce:
+    a: 606016
+    b: 0
+    c: 0
+    d: 13835058056920509601
+  Addr: 127.0.0.1:2146
+  PublicKey: 03ae859eac5b72ee428c7a85f10b2ce748d9de5e480aefbb70f6597dfa8b2175e5
+  Role: Miner
diff --git a/test/compatibility/node_1/private.key b/test/compatibility/node_1/private.key
new file mode 100644
index 000000000..449618c0a
--- /dev/null
+++ b/test/compatibility/node_1/private.key
@@ -0,0 +1,2 @@
+WAð�8��#|�T��Z�ԓ�`�mF�}�~�e��ʆ?�~�����*E��%���v�����p�o*a߂�ç_Bľ@8
+��M�C2�
\ No newline at end of file
diff --git a/test/compatibility/node_2/config.yaml b/test/compatibility/node_2/config.yaml
new file mode 100644
index 000000000..30a422bc3
--- /dev/null
+++ b/test/compatibility/node_2/config.yaml
@@ -0,0 +1,122 @@
+IsTestMode: true
+WorkingRoot: "./"
+PubKeyStoreFile: "public.keystore"
+PrivateKeyFile: "private.key"
+DHTFileName: "dht.db"
+ListenAddr: "127.0.0.1:3120"
+ThisNodeID: "000000172580063ded88e010556b0aca2851265be8845b1ef397e8fce6ab5582"
+QPS: 1000
+BillingBlockCount: 2
+ChainBusPeriod: 1s
+BPPeriod: 3s
+BPTick: 1s
+SQLChainPeriod: 3s
+SQLChainTick: 1s
+SQLChainTTL: 10
+MinProviderDeposit: 1000000
+ValidDNSKeys:
+  koPbw9wmYZ7ggcjnQ6ayHyhHaDNMYELKTqT+qRGrZpWSccr/lBcrm10Z1PuQHB3Azhii+sb0PYFkH1ruxLhe5g==: cloudflare.com
+  mdsswUyr3DPW132mOi8V9xESWE8jTo0dxCjjnopKl+GqJxpVXckHAeF+KkxLbxILfDLUT0rAK9iUzy1L53eKGQ==: cloudflare.com
+  oJMRESz5E4gYzS/q6XDrvU1qMPYIjCWzJaOau8XNEZeqCYKD5ar0IRd8KqXXFJkqmVfRvMGPmM1x8fGAa2XhSA==: cloudflare.com
+MinNodeIDDifficulty: 2
+DNSSeed:
+  EnforcedDNSSEC: false
+  DNSServers:
+  - 1.1.1.1
+  - 202.46.34.74
+  - 202.46.34.75
+  - 202.46.34.76
+
+BlockProducer:
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  NodeID: 00000bef611d346c0cbe1beaa76e7f0ed705a194fdf9ac3a248ec70e9c198bf9
+  Nonce:
+    a: 313283
+    b: 0
+    c: 0
+    d: 0
+  ChainFileName: "chain.db"
+  BPGenesisInfo:
+    Version: 1
+    BlockHash: f745ca6427237aac858dd3c7f2df8e6f3c18d0f1c164e07a1c6b8eebeba6b154
+    Producer: 0000000000000000000000000000000000000000000000000000000000000001
+    MerkleRoot: 0000000000000000000000000000000000000000000000000000000000000001
+    ParentHash: 0000000000000000000000000000000000000000000000000000000000000001
+    Timestamp: 2018-08-13T21:59:59.12Z
+    BaseAccounts:
+      - Address: ba0ba731c7a76ccef2c1170f42038f7e228dfb474ef0190dfe35d9a37911ed37
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+      - Address: 1a7b0959bbd0d0ec529278a61c0056c277bffe75b2646e1699b46b10a90210be
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+      - Address: 9235bc4130a2ed4e6c35ea189dab35198ebb105640bedb97dd5269cc80863b16
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+      - Address: 9e1618775cceeb19f110e04fbc6c5bca6c8e4e9b116e193a42fe69bf602e7bcd
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+KnownNodes:
+- ID: 00000bef611d346c0cbe1beaa76e7f0ed705a194fdf9ac3a248ec70e9c198bf9
+  Nonce:
+    a: 313283
+    b: 0
+    c: 0
+    d: 0
+  Addr: 127.0.0.1:3122
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  Role: Leader
+- ID: 00000381d46fd6cf7742d7fb94e2422033af989c0e348b5781b3219599a3af35
+  Nonce:
+    a: 478373
+    b: 0
+    c: 0
+    d: 2305843009893772025
+  Addr: 127.0.0.1:3121
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  Role: Follower
+- ID: 000000172580063ded88e010556b0aca2851265be8845b1ef397e8fce6ab5582
+  Nonce:
+    a: 259939
+    b: 0
+    c: 0
+    d: 2305843012544226372
+  Addr: 127.0.0.1:3120
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  Role: Follower
+- ID: 00000f3b43288fe99831eb533ab77ec455d13e11fc38ec35a42d4edd17aa320d
+  Nonce:
+    a: 22403
+    b: 0
+    c: 0
+    d: 0
+  Addr: ""
+  PublicKey: 02ec784ca599f21ef93fe7abdc68d78817ab6c9b31f2324d15ea174d9da498b4c4
+  Role: Client
+- ID: 000005aa62048f85da4ae9698ed59c14ec0d48a88a07c15a32265634e7e64ade
+  Nonce:
+    a: 567323
+    b: 0
+    c: 0
+    d: 3104982049
+  Addr: 127.0.0.1:2144
+  PublicKey: 0367aa51809a7c1dc0f82c02452fec9557b3e1d10ce7c919d8e73d90048df86d20
+  Role: Miner
+- ID: 000005f4f22c06f76c43c4f48d5a7ec1309cc94030cbf9ebae814172884ac8b5
+  Nonce:
+    a: 240524
+    b: 0
+    c: 0
+    d: 2305843010430351476
+  Addr: 127.0.0.1:2145
+  PublicKey: 02914bca0806f040dd842207c44474ab41ecd29deee7f2d355789c5c78d448ca16
+  Role: Miner
+- ID: 000003f49592f83d0473bddb70d543f1096b4ffed5e5f942a3117e256b7052b8
+  Nonce:
+    a: 606016
+    b: 0
+    c: 0
+    d: 13835058056920509601
+  Addr: 127.0.0.1:2146
+  PublicKey: 03ae859eac5b72ee428c7a85f10b2ce748d9de5e480aefbb70f6597dfa8b2175e5
+  Role: Miner
diff --git a/test/compatibility/node_2/private.key b/test/compatibility/node_2/private.key
new file mode 100644
index 000000000..449618c0a
--- /dev/null
+++ b/test/compatibility/node_2/private.key
@@ -0,0 +1,2 @@
+WAð�8��#|�T��Z�ԓ�`�mF�}�~�e��ʆ?�~�����*E��%���v�����p�o*a߂�ç_Bľ@8
+��M�C2�
\ No newline at end of file
diff --git a/test/compatibility/node_c/config.yaml b/test/compatibility/node_c/config.yaml
new file mode 100644
index 000000000..84320e6c2
--- /dev/null
+++ b/test/compatibility/node_c/config.yaml
@@ -0,0 +1,122 @@
+IsTestMode: true
+WorkingRoot: "./"
+PubKeyStoreFile: "public.keystore"
+PrivateKeyFile: "private.key"
+DHTFileName: "dht.db"
+ListenAddr: "127.0.0.1:3120"
+ThisNodeID: "00000f3b43288fe99831eb533ab77ec455d13e11fc38ec35a42d4edd17aa320d"
+QPS: 1000
+BillingBlockCount: 2
+ChainBusPeriod: 1s
+BPPeriod: 3s
+BPTick: 1s
+SQLChainPeriod: 3s
+SQLChainTick: 1s
+SQLChainTTL: 10
+MinProviderDeposit: 1000000
+ValidDNSKeys:
+  koPbw9wmYZ7ggcjnQ6ayHyhHaDNMYELKTqT+qRGrZpWSccr/lBcrm10Z1PuQHB3Azhii+sb0PYFkH1ruxLhe5g==: cloudflare.com
+  mdsswUyr3DPW132mOi8V9xESWE8jTo0dxCjjnopKl+GqJxpVXckHAeF+KkxLbxILfDLUT0rAK9iUzy1L53eKGQ==: cloudflare.com
+  oJMRESz5E4gYzS/q6XDrvU1qMPYIjCWzJaOau8XNEZeqCYKD5ar0IRd8KqXXFJkqmVfRvMGPmM1x8fGAa2XhSA==: cloudflare.com
+MinNodeIDDifficulty: 2
+DNSSeed:
+  EnforcedDNSSEC: false
+  DNSServers:
+  - 1.1.1.1
+  - 202.46.34.74
+  - 202.46.34.75
+  - 202.46.34.76
+
+BlockProducer:
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  NodeID: 00000bef611d346c0cbe1beaa76e7f0ed705a194fdf9ac3a248ec70e9c198bf9
+  Nonce:
+    a: 313283
+    b: 0
+    c: 0
+    d: 0
+  ChainFileName: "chain.db"
+  BPGenesisInfo:
+    Version: 1
+    BlockHash: f745ca6427237aac858dd3c7f2df8e6f3c18d0f1c164e07a1c6b8eebeba6b154
+    Producer: 0000000000000000000000000000000000000000000000000000000000000001
+    MerkleRoot: 0000000000000000000000000000000000000000000000000000000000000001
+    ParentHash: 0000000000000000000000000000000000000000000000000000000000000001
+    Timestamp: 2018-08-13T21:59:59.12Z
+    BaseAccounts:
+      - Address: ba0ba731c7a76ccef2c1170f42038f7e228dfb474ef0190dfe35d9a37911ed37
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+      - Address: 1a7b0959bbd0d0ec529278a61c0056c277bffe75b2646e1699b46b10a90210be
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+      - Address: 9235bc4130a2ed4e6c35ea189dab35198ebb105640bedb97dd5269cc80863b16
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+      - Address: 9e1618775cceeb19f110e04fbc6c5bca6c8e4e9b116e193a42fe69bf602e7bcd
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+KnownNodes:
+- ID: 00000bef611d346c0cbe1beaa76e7f0ed705a194fdf9ac3a248ec70e9c198bf9
+  Nonce:
+    a: 313283
+    b: 0
+    c: 0
+    d: 0
+  Addr: 127.0.0.1:3122
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  Role: Leader
+- ID: 00000381d46fd6cf7742d7fb94e2422033af989c0e348b5781b3219599a3af35
+  Nonce:
+    a: 478373
+    b: 0
+    c: 0
+    d: 2305843009893772025
+  Addr: 127.0.0.1:3121
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  Role: Follower
+- ID: 000000172580063ded88e010556b0aca2851265be8845b1ef397e8fce6ab5582
+  Nonce:
+    a: 259939
+    b: 0
+    c: 0
+    d: 2305843012544226372
+  Addr: 127.0.0.1:3120
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  Role: Follower
+- ID: 00000f3b43288fe99831eb533ab77ec455d13e11fc38ec35a42d4edd17aa320d
+  Nonce:
+    a: 22403
+    b: 0
+    c: 0
+    d: 0
+  Addr: ""
+  PublicKey: 02ec784ca599f21ef93fe7abdc68d78817ab6c9b31f2324d15ea174d9da498b4c4
+  Role: Client
+- ID: 000005aa62048f85da4ae9698ed59c14ec0d48a88a07c15a32265634e7e64ade
+  Nonce:
+    a: 567323
+    b: 0
+    c: 0
+    d: 3104982049
+  Addr: 127.0.0.1:2144
+  PublicKey: 0367aa51809a7c1dc0f82c02452fec9557b3e1d10ce7c919d8e73d90048df86d20
+  Role: Miner
+- ID: 000005f4f22c06f76c43c4f48d5a7ec1309cc94030cbf9ebae814172884ac8b5
+  Nonce:
+    a: 240524
+    b: 0
+    c: 0
+    d: 2305843010430351476
+  Addr: 127.0.0.1:2145
+  PublicKey: 02914bca0806f040dd842207c44474ab41ecd29deee7f2d355789c5c78d448ca16
+  Role: Miner
+- ID: 000003f49592f83d0473bddb70d543f1096b4ffed5e5f942a3117e256b7052b8
+  Nonce:
+    a: 606016
+    b: 0
+    c: 0
+    d: 13835058056920509601
+  Addr: 127.0.0.1:2146
+  PublicKey: 03ae859eac5b72ee428c7a85f10b2ce748d9de5e480aefbb70f6597dfa8b2175e5
+  Role: Miner
diff --git a/test/compatibility/node_c/private.key b/test/compatibility/node_c/private.key
new file mode 100644
index 000000000..f563980c1
Binary files /dev/null and b/test/compatibility/node_c/private.key differ
diff --git a/test/compatibility/node_miner_0/config.yaml b/test/compatibility/node_miner_0/config.yaml
new file mode 100644
index 000000000..ce99baf98
--- /dev/null
+++ b/test/compatibility/node_miner_0/config.yaml
@@ -0,0 +1,118 @@
+IsTestMode: true
+WorkingRoot: "./"
+PubKeyStoreFile: "public.keystore"
+PrivateKeyFile: "private.key"
+DHTFileName: "dht.db"
+ListenAddr: "127.0.0.1:2144"
+ThisNodeID: "000005aa62048f85da4ae9698ed59c14ec0d48a88a07c15a32265634e7e64ade"
+QPS: 1000
+BillingBlockCount: 2
+ChainBusPeriod: 1s
+BPPeriod: 3s
+BPTick: 1s
+SQLChainPeriod: 3s
+SQLChainTick: 1s
+SQLChainTTL: 10
+MinProviderDeposit: 1000000
+ValidDNSKeys:
+  koPbw9wmYZ7ggcjnQ6ayHyhHaDNMYELKTqT+qRGrZpWSccr/lBcrm10Z1PuQHB3Azhii+sb0PYFkH1ruxLhe5g==: cloudflare.com
+  mdsswUyr3DPW132mOi8V9xESWE8jTo0dxCjjnopKl+GqJxpVXckHAeF+KkxLbxILfDLUT0rAK9iUzy1L53eKGQ==: cloudflare.com
+  oJMRESz5E4gYzS/q6XDrvU1qMPYIjCWzJaOau8XNEZeqCYKD5ar0IRd8KqXXFJkqmVfRvMGPmM1x8fGAa2XhSA==: cloudflare.com
+BlockProducer:
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  NodeID: 00000bef611d346c0cbe1beaa76e7f0ed705a194fdf9ac3a248ec70e9c198bf9
+  Nonce:
+    a: 313283
+    b: 0
+    c: 0
+    d: 0
+  ChainFileName: "chain.db"
+  BPGenesisInfo:
+    Version: 1
+    BlockHash: f745ca6427237aac858dd3c7f2df8e6f3c18d0f1c164e07a1c6b8eebeba6b154
+    Producer: 0000000000000000000000000000000000000000000000000000000000000001
+    MerkleRoot: 0000000000000000000000000000000000000000000000000000000000000001
+    ParentHash: 0000000000000000000000000000000000000000000000000000000000000001
+    Timestamp: 2018-08-13T21:59:59.12Z
+    BaseAccounts:
+      - Address: ba0ba731c7a76ccef2c1170f42038f7e228dfb474ef0190dfe35d9a37911ed37
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+      - Address: 1a7b0959bbd0d0ec529278a61c0056c277bffe75b2646e1699b46b10a90210be
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+      - Address: 9235bc4130a2ed4e6c35ea189dab35198ebb105640bedb97dd5269cc80863b16
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+      - Address: 9e1618775cceeb19f110e04fbc6c5bca6c8e4e9b116e193a42fe69bf602e7bcd
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+Miner:
+  IsTestMode: true
+  RootDir: "./data"
+  MaxReqTimeGap: "2s"
+  ProvideServiceInterval: "60s"
+KnownNodes:
+- ID: 00000bef611d346c0cbe1beaa76e7f0ed705a194fdf9ac3a248ec70e9c198bf9
+  Nonce:
+    a: 313283
+    b: 0
+    c: 0
+    d: 0
+  Addr: 127.0.0.1:3122
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  Role: Leader
+- ID: 00000381d46fd6cf7742d7fb94e2422033af989c0e348b5781b3219599a3af35
+  Nonce:
+    a: 478373
+    b: 0
+    c: 0
+    d: 2305843009893772025
+  Addr: 127.0.0.1:3121
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  Role: Follower
+- ID: 000000172580063ded88e010556b0aca2851265be8845b1ef397e8fce6ab5582
+  Nonce:
+    a: 259939
+    b: 0
+    c: 0
+    d: 2305843012544226372
+  Addr: 127.0.0.1:3120
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  Role: Follower
+- ID: 00000f3b43288fe99831eb533ab77ec455d13e11fc38ec35a42d4edd17aa320d
+  Nonce:
+    a: 22403
+    b: 0
+    c: 0
+    d: 0
+  Addr: ""
+  PublicKey: 02ec784ca599f21ef93fe7abdc68d78817ab6c9b31f2324d15ea174d9da498b4c4
+  Role: Client
+- ID: 000005aa62048f85da4ae9698ed59c14ec0d48a88a07c15a32265634e7e64ade
+  Nonce:
+    a: 567323
+    b: 0
+    c: 0
+    d: 3104982049
+  Addr: 127.0.0.1:2144
+  PublicKey: 0367aa51809a7c1dc0f82c02452fec9557b3e1d10ce7c919d8e73d90048df86d20
+  Role: Miner
+- ID: 000005f4f22c06f76c43c4f48d5a7ec1309cc94030cbf9ebae814172884ac8b5
+  Nonce:
+    a: 240524
+    b: 0
+    c: 0
+    d: 2305843010430351476
+  Addr: 127.0.0.1:2145
+  PublicKey: 02914bca0806f040dd842207c44474ab41ecd29deee7f2d355789c5c78d448ca16
+  Role: Miner
+- ID: 000003f49592f83d0473bddb70d543f1096b4ffed5e5f942a3117e256b7052b8
+  Nonce:
+    a: 606016
+    b: 0
+    c: 0
+    d: 13835058056920509601
+  Addr: 127.0.0.1:2146
+  PublicKey: 03ae859eac5b72ee428c7a85f10b2ce748d9de5e480aefbb70f6597dfa8b2175e5
+  Role: Miner
diff --git a/test/compatibility/node_miner_0/private.key b/test/compatibility/node_miner_0/private.key
new file mode 100644
index 000000000..12e7d3d80
--- /dev/null
+++ b/test/compatibility/node_miner_0/private.key
@@ -0,0 +1 @@
+�8s�_/W�-7Iy�����H_�D����y������T�G����*�M9C#8p%��x�>�S���ߪ�RLmP�B>{�:�̜�����뢷|��|
\ No newline at end of file
diff --git a/test/compatibility/node_miner_1/config.yaml b/test/compatibility/node_miner_1/config.yaml
new file mode 100644
index 000000000..6cec5bbc7
--- /dev/null
+++ b/test/compatibility/node_miner_1/config.yaml
@@ -0,0 +1,118 @@
+IsTestMode: true
+WorkingRoot: "./"
+PubKeyStoreFile: "public.keystore"
+PrivateKeyFile: "private.key"
+DHTFileName: "dht.db"
+ListenAddr: "127.0.0.1:2145"
+ThisNodeID: "000005f4f22c06f76c43c4f48d5a7ec1309cc94030cbf9ebae814172884ac8b5"
+QPS: 1000
+BillingBlockCount: 2
+ChainBusPeriod: 1s
+BPPeriod: 3s
+BPTick: 1s
+SQLChainPeriod: 3s
+SQLChainTick: 1s
+SQLChainTTL: 10
+MinProviderDeposit: 1000000
+ValidDNSKeys:
+  koPbw9wmYZ7ggcjnQ6ayHyhHaDNMYELKTqT+qRGrZpWSccr/lBcrm10Z1PuQHB3Azhii+sb0PYFkH1ruxLhe5g==: cloudflare.com
+  mdsswUyr3DPW132mOi8V9xESWE8jTo0dxCjjnopKl+GqJxpVXckHAeF+KkxLbxILfDLUT0rAK9iUzy1L53eKGQ==: cloudflare.com
+  oJMRESz5E4gYzS/q6XDrvU1qMPYIjCWzJaOau8XNEZeqCYKD5ar0IRd8KqXXFJkqmVfRvMGPmM1x8fGAa2XhSA==: cloudflare.com
+BlockProducer:
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  NodeID: 00000bef611d346c0cbe1beaa76e7f0ed705a194fdf9ac3a248ec70e9c198bf9
+  Nonce:
+    a: 313283
+    b: 0
+    c: 0
+    d: 0
+  ChainFileName: "chain.db"
+  BPGenesisInfo:
+    Version: 1
+    BlockHash: f745ca6427237aac858dd3c7f2df8e6f3c18d0f1c164e07a1c6b8eebeba6b154
+    Producer: 0000000000000000000000000000000000000000000000000000000000000001
+    MerkleRoot: 0000000000000000000000000000000000000000000000000000000000000001
+    ParentHash: 0000000000000000000000000000000000000000000000000000000000000001
+    Timestamp: 2018-08-13T21:59:59.12Z
+    BaseAccounts:
+      - Address: ba0ba731c7a76ccef2c1170f42038f7e228dfb474ef0190dfe35d9a37911ed37
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+      - Address: 1a7b0959bbd0d0ec529278a61c0056c277bffe75b2646e1699b46b10a90210be
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+      - Address: 9235bc4130a2ed4e6c35ea189dab35198ebb105640bedb97dd5269cc80863b16
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+      - Address: 9e1618775cceeb19f110e04fbc6c5bca6c8e4e9b116e193a42fe69bf602e7bcd
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+Miner:
+  IsTestMode: true
+  RootDir: "./data"
+  MaxReqTimeGap: "2s"
+  ProvideServiceInterval: "60s"
+KnownNodes:
+- ID: 00000bef611d346c0cbe1beaa76e7f0ed705a194fdf9ac3a248ec70e9c198bf9
+  Nonce:
+    a: 313283
+    b: 0
+    c: 0
+    d: 0
+  Addr: 127.0.0.1:3122
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  Role: Leader
+- ID: 00000381d46fd6cf7742d7fb94e2422033af989c0e348b5781b3219599a3af35
+  Nonce:
+    a: 478373
+    b: 0
+    c: 0
+    d: 2305843009893772025
+  Addr: 127.0.0.1:3121
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  Role: Follower
+- ID: 000000172580063ded88e010556b0aca2851265be8845b1ef397e8fce6ab5582
+  Nonce:
+    a: 259939
+    b: 0
+    c: 0
+    d: 2305843012544226372
+  Addr: 127.0.0.1:3120
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  Role: Follower
+- ID: 00000f3b43288fe99831eb533ab77ec455d13e11fc38ec35a42d4edd17aa320d
+  Nonce:
+    a: 22403
+    b: 0
+    c: 0
+    d: 0
+  Addr: ""
+  PublicKey: 02ec784ca599f21ef93fe7abdc68d78817ab6c9b31f2324d15ea174d9da498b4c4
+  Role: Client
+- ID: 000005aa62048f85da4ae9698ed59c14ec0d48a88a07c15a32265634e7e64ade
+  Nonce:
+    a: 567323
+    b: 0
+    c: 0
+    d: 3104982049
+  Addr: 127.0.0.1:2144
+  PublicKey: 0367aa51809a7c1dc0f82c02452fec9557b3e1d10ce7c919d8e73d90048df86d20
+  Role: Miner
+- ID: 000005f4f22c06f76c43c4f48d5a7ec1309cc94030cbf9ebae814172884ac8b5
+  Nonce:
+    a: 240524
+    b: 0
+    c: 0
+    d: 2305843010430351476
+  Addr: 127.0.0.1:2145
+  PublicKey: 02914bca0806f040dd842207c44474ab41ecd29deee7f2d355789c5c78d448ca16
+  Role: Miner
+- ID: 000003f49592f83d0473bddb70d543f1096b4ffed5e5f942a3117e256b7052b8
+  Nonce:
+    a: 606016
+    b: 0
+    c: 0
+    d: 13835058056920509601
+  Addr: 127.0.0.1:2146
+  PublicKey: 03ae859eac5b72ee428c7a85f10b2ce748d9de5e480aefbb70f6597dfa8b2175e5
+  Role: Miner
diff --git a/test/compatibility/node_miner_1/private.key b/test/compatibility/node_miner_1/private.key
new file mode 100644
index 000000000..44e8915e6
--- /dev/null
+++ b/test/compatibility/node_miner_1/private.key
@@ -0,0 +1,2 @@
+s]�](�o��3R��
+D5�*����9��C
�7�Z�in�ƋSp�*S�S5�^����ޑ��a��x�>�Xо2�#�I�xR�w��+��Ŕ
\ No newline at end of file
diff --git a/test/compatibility/node_miner_2/config.yaml b/test/compatibility/node_miner_2/config.yaml
new file mode 100644
index 000000000..ec0ac5060
--- /dev/null
+++ b/test/compatibility/node_miner_2/config.yaml
@@ -0,0 +1,118 @@
+IsTestMode: true
+WorkingRoot: "./"
+PubKeyStoreFile: "public.keystore"
+PrivateKeyFile: "private.key"
+DHTFileName: "dht.db"
+ListenAddr: "127.0.0.1:2146"
+ThisNodeID: "000003f49592f83d0473bddb70d543f1096b4ffed5e5f942a3117e256b7052b8"
+QPS: 1000
+BillingBlockCount: 2
+ChainBusPeriod: 1s
+BPPeriod: 3s
+BPTick: 1s
+SQLChainPeriod: 3s
+SQLChainTick: 1s
+SQLChainTTL: 10
+MinProviderDeposit: 1000000
+ValidDNSKeys:
+  koPbw9wmYZ7ggcjnQ6ayHyhHaDNMYELKTqT+qRGrZpWSccr/lBcrm10Z1PuQHB3Azhii+sb0PYFkH1ruxLhe5g==: cloudflare.com
+  mdsswUyr3DPW132mOi8V9xESWE8jTo0dxCjjnopKl+GqJxpVXckHAeF+KkxLbxILfDLUT0rAK9iUzy1L53eKGQ==: cloudflare.com
+  oJMRESz5E4gYzS/q6XDrvU1qMPYIjCWzJaOau8XNEZeqCYKD5ar0IRd8KqXXFJkqmVfRvMGPmM1x8fGAa2XhSA==: cloudflare.com
+BlockProducer:
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  NodeID: 00000bef611d346c0cbe1beaa76e7f0ed705a194fdf9ac3a248ec70e9c198bf9
+  Nonce:
+    a: 313283
+    b: 0
+    c: 0
+    d: 0
+  ChainFileName: "chain.db"
+  BPGenesisInfo:
+    Version: 1
+    BlockHash: f745ca6427237aac858dd3c7f2df8e6f3c18d0f1c164e07a1c6b8eebeba6b154
+    Producer: 0000000000000000000000000000000000000000000000000000000000000001
+    MerkleRoot: 0000000000000000000000000000000000000000000000000000000000000001
+    ParentHash: 0000000000000000000000000000000000000000000000000000000000000001
+    Timestamp: 2018-08-13T21:59:59.12Z
+    BaseAccounts:
+      - Address: ba0ba731c7a76ccef2c1170f42038f7e228dfb474ef0190dfe35d9a37911ed37
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+      - Address: 1a7b0959bbd0d0ec529278a61c0056c277bffe75b2646e1699b46b10a90210be
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+      - Address: 9235bc4130a2ed4e6c35ea189dab35198ebb105640bedb97dd5269cc80863b16
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+      - Address: 9e1618775cceeb19f110e04fbc6c5bca6c8e4e9b116e193a42fe69bf602e7bcd
+        StableCoinBalance: 10000000000000000000
+        CovenantCoinBalance: 10000000000000000000
+Miner:
+  IsTestMode: true
+  RootDir: "./data"
+  MaxReqTimeGap: "2s"
+  ProvideServiceInterval: "60s"
+KnownNodes:
+- ID: 00000bef611d346c0cbe1beaa76e7f0ed705a194fdf9ac3a248ec70e9c198bf9
+  Nonce:
+    a: 313283
+    b: 0
+    c: 0
+    d: 0
+  Addr: 127.0.0.1:3122
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  Role: Leader
+- ID: 00000381d46fd6cf7742d7fb94e2422033af989c0e348b5781b3219599a3af35
+  Nonce:
+    a: 478373
+    b: 0
+    c: 0
+    d: 2305843009893772025
+  Addr: 127.0.0.1:3121
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  Role: Follower
+- ID: 000000172580063ded88e010556b0aca2851265be8845b1ef397e8fce6ab5582
+  Nonce:
+    a: 259939
+    b: 0
+    c: 0
+    d: 2305843012544226372
+  Addr: 127.0.0.1:3120
+  PublicKey: "02c76216704d797c64c58bc11519fb68582e8e63de7e5b3b2dbbbe8733efe5fd24"
+  Role: Follower
+- ID: 00000f3b43288fe99831eb533ab77ec455d13e11fc38ec35a42d4edd17aa320d
+  Nonce:
+    a: 22403
+    b: 0
+    c: 0
+    d: 0
+  Addr: ""
+  PublicKey: 02ec784ca599f21ef93fe7abdc68d78817ab6c9b31f2324d15ea174d9da498b4c4
+  Role: Client
+- ID: 000005aa62048f85da4ae9698ed59c14ec0d48a88a07c15a32265634e7e64ade
+  Nonce:
+    a: 567323
+    b: 0
+    c: 0
+    d: 3104982049
+  Addr: 127.0.0.1:2144
+  PublicKey: 0367aa51809a7c1dc0f82c02452fec9557b3e1d10ce7c919d8e73d90048df86d20
+  Role: Miner
+- ID: 000005f4f22c06f76c43c4f48d5a7ec1309cc94030cbf9ebae814172884ac8b5
+  Nonce:
+    a: 240524
+    b: 0
+    c: 0
+    d: 2305843010430351476
+  Addr: 127.0.0.1:2145
+  PublicKey: 02914bca0806f040dd842207c44474ab41ecd29deee7f2d355789c5c78d448ca16
+  Role: Miner
+- ID: 000003f49592f83d0473bddb70d543f1096b4ffed5e5f942a3117e256b7052b8
+  Nonce:
+    a: 606016
+    b: 0
+    c: 0
+    d: 13835058056920509601
+  Addr: 127.0.0.1:2146
+  PublicKey: 03ae859eac5b72ee428c7a85f10b2ce748d9de5e480aefbb70f6597dfa8b2175e5
+  Role: Miner
diff --git a/test/compatibility/node_miner_2/private.key b/test/compatibility/node_miner_2/private.key
new file mode 100644
index 000000000..adb437e75
--- /dev/null
+++ b/test/compatibility/node_miner_2/private.key
@@ -0,0 +1 @@
+�6������i.i%8p�VV���r���L�BK�b: ��1;(���f����F&���y���췥 ��R�W3��?C�A���;e"K2�
\ No newline at end of file
diff --git a/test/compatibility/specific_old.sh b/test/compatibility/specific_old.sh
new file mode 100755
index 000000000..eec7174ee
--- /dev/null
+++ b/test/compatibility/specific_old.sh
@@ -0,0 +1,69 @@
+#!/bin/bash -x
+test_case=$1
+set -e
+
+TEST_WD=$(cd $(dirname $0)/; pwd)
+PROJECT_DIR=$(cd ${TEST_WD}/../../; pwd)
+
+OLD_BIN_DIR=${CACHE_DIR}/${PREV_VERSION}
+NEW_BIN_DIR=${PROJECT_DIR}/bin
+
+LOGS_DIR=${PIPELINE_CACHE}/logs/old_${test_case}
+mkdir -p ${LOGS_DIR}
+
+case $test_case in
+    "client")
+        CLIENTBIN=${OLD_BIN_DIR}/cql
+        BPBIN=${NEW_BIN_DIR}/cqld
+        MINERBIN=${NEW_BIN_DIR}/cql-minerd
+        ;;
+    "bp")
+        CLIENTBIN=${NEW_BIN_DIR}/cql
+        BPBIN=${OLD_BIN_DIR}/cqld
+        MINERBIN=${NEW_BIN_DIR}/cql-minerd
+        ;;
+    "miner")
+        CLIENTBIN=${NEW_BIN_DIR}/cql
+        BPBIN=${NEW_BIN_DIR}/cqld
+        MINERBIN=${OLD_BIN_DIR}/cql-minerd
+        ;;
+    *)
+        exit 1
+        ;;
+esac
+
+cd ${TEST_WD}
+# start bp
+nohup ${BPBIN} -config node_0/config.yaml >${LOGS_DIR}/bp0.log 2>&1 &
+nohup ${BPBIN} -config node_1/config.yaml >${LOGS_DIR}/bp1.log 2>&1 &
+nohup ${BPBIN} -config node_2/config.yaml >${LOGS_DIR}/bp2.log 2>&1 &
+
+# wait bp start
+sleep 20
+
+# start miner
+nohup ${MINERBIN} -config node_miner_0/config.yaml >${LOGS_DIR}/miner0.log 2>&1 &
+nohup ${MINERBIN} -config node_miner_1/config.yaml >${LOGS_DIR}/miner1.log 2>&1 &
+nohup ${MINERBIN} -config node_miner_2/config.yaml >${LOGS_DIR}/miner2.log 2>&1 &
+
+# wait miner start
+sleep 20
+
+${CLIENTBIN} -config node_c/config.yaml -get-balance
+
+${CLIENTBIN} -config node_c/config.yaml -create 2 -wait-tx-confirm | tee dsn.txt
+
+#get dsn
+dsn=$(cat dsn.txt)
+if [ -z "$dsn" ]; then
+    exit 1
+fi
+
+${CLIENTBIN} -config ${PROJECT_DIR}/test/integration/node_c/config.yaml -dsn ${dsn} \
+    -command 'create table test_for_new_account(column1 int);'
+
+${CLIENTBIN} -config ${PROJECT_DIR}/test/integration/node_c/config.yaml -dsn ${dsn} \
+    -command 'show tables;' | tee result.log
+
+grep "1 row" result.log
+
diff --git a/test/testnet_client/run.sh b/test/testnet_client/run.sh
index a17511d0c..5e53cd7d2 100755
--- a/test/testnet_client/run.sh
+++ b/test/testnet_client/run.sh
@@ -1,9 +1,9 @@
 #!/bin/bash -x
-
 set -e
 
 TEST_WD=$(cd $(dirname $0)/; pwd)
 PROJECT_DIR=$(cd ${TEST_WD}/../../; pwd)
+BIN=${PROJECT_DIR}/bin
 
 echo ${PROJECT_DIR}
 
@@ -12,27 +12,28 @@ echo ${PROJECT_DIR}
 # cd ${PROJECT_DIR} && make use_all_cores
 
 cd ${TEST_WD}
-echo -ne "y\n" | ${PROJECT_DIR}/bin/cql-utils -tool confgen -skip-master-key
-${PROJECT_DIR}/bin/cql-utils -tool addrgen -skip-master-key | tee wallet.txt
+
+echo -ne "y\n" | ${BIN}/cql-utils -tool confgen -skip-master-key
 
 #get wallet addr
+${BIN}/cql-utils -tool addrgen -skip-master-key | tee wallet.txt
 wallet=$(awk '{print $3}' wallet.txt)
 
 #transfer some coin to above address
-${PROJECT_DIR}/bin/cql -config ${PROJECT_DIR}/conf/testnet/config.yaml -transfer \
+${BIN}/cql -config ${PROJECT_DIR}/conf/testnet/config.yaml -transfer \
     '{"addr":"'${wallet}'", "amount":"100000000 Particle"}' -wait-tx-confirm
 
-${PROJECT_DIR}/bin/cql -get-balance
+${BIN}/cql -get-balance
 
-${PROJECT_DIR}/bin/cql -create 2 -wait-tx-confirm | tee dsn.txt
+${BIN}/cql -create 2 -wait-tx-confirm | tee dsn.txt
 
 #get dsn
 dsn=$(cat dsn.txt)
 
-${PROJECT_DIR}/bin/cql -dsn ${dsn} \
+${BIN}/cql -dsn ${dsn} \
     -command 'create table test_for_new_account(column1 int);'
 
-${PROJECT_DIR}/bin/cql -dsn ${dsn} \
+${BIN}/cql -dsn ${dsn} \
     -command 'show tables;' | tee result.log
 
 grep "1 row" result.log
diff --git a/utils/log/debug/handler.go b/utils/log/debug/handler.go
new file mode 100644
index 000000000..45a3fa45b
--- /dev/null
+++ b/utils/log/debug/handler.go
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2019 The CovenantSQL Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package debug
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/CovenantSQL/CovenantSQL/utils/log"
+)
+
+func init() {
+	http.HandleFunc("/debug/covenantsql/loglevel",
+		func(w http.ResponseWriter, req *http.Request) {
+			data := map[string]interface{}{}
+			switch req.Method {
+			case http.MethodPost:
+				level := req.FormValue("level")
+				data["orig"] = log.GetLevel().String()
+				if level != "" {
+					data["want"] = level
+					lvl, err := log.ParseLevel(level)
+					if err != nil {
+						data["err"] = err.Error()
+					} else {
+						// set level
+						log.SetLevel(lvl)
+					}
+				}
+				fallthrough
+			case http.MethodGet:
+				data["level"] = log.GetLevel().String()
+				_ = json.NewEncoder(w).Encode(data)
+			default:
+				w.WriteHeader(http.StatusBadRequest)
+			}
+		},
+	)
+}
diff --git a/utils/log/debug/handler_test.go b/utils/log/debug/handler_test.go
new file mode 100644
index 000000000..8ba588dd2
--- /dev/null
+++ b/utils/log/debug/handler_test.go
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2019 The CovenantSQL Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package debug_test
+
+import (
+	"encoding/json"
+	"net"
+	"net/http"
+	"testing"
+
+	"github.com/jmoiron/jsonq"
+	. "github.com/smartystreets/goconvey/convey"
+
+	"github.com/CovenantSQL/CovenantSQL/utils/log"
+)
+
+func parseResponse(resp *http.Response, r error) (result *jsonq.JsonQuery, err error) {
+	if r != nil {
+		err = r
+		return
+	}
+
+	var res map[string]interface{}
+	err = json.NewDecoder(resp.Body).Decode(&res)
+	if err != nil {
+		return
+	}
+
+	result = jsonq.NewQuery(res)
+	return
+}
+
+func mustJSONQ(c C) func(interface{}, error) interface{} {
+	return func(i interface{}, e error) interface{} {
+		c.So(e, ShouldBeNil)
+		return i
+	}
+}
+
+func TestDebugHandler(t *testing.T) {
+	Convey("test debug handler", t, func(c C) {
+		server := http.Server{}
+		listener, err := net.Listen("tcp", ":0")
+		So(err, ShouldBeNil)
+		defer func() {
+			_ = listener.Close()
+		}()
+		go func() {
+			_ = server.Serve(listener)
+		}()
+		log.SetLevel(log.DebugLevel)
+		url := "http://" + listener.Addr().String() + "/debug/covenantsql/loglevel"
+		resp, err := parseResponse(http.Get(url))
+		So(err, ShouldBeNil)
+		So(mustJSONQ(c)(resp.String("level")), ShouldEqual, log.GetLevel().String())
+		resp, err = parseResponse(http.PostForm(url, map[string][]string{"level": {"fatal"}}))
+		So(err, ShouldBeNil)
+		So(mustJSONQ(c)(resp.String("level")), ShouldEqual, log.GetLevel().String())
+		So(log.GetLevel().String(), ShouldEqual, "fatal")
+		So(mustJSONQ(c)(resp.String("orig")), ShouldEqual, "debug")
+		So(mustJSONQ(c)(resp.String("want")), ShouldEqual, "fatal")
+		resp, err = parseResponse(http.PostForm(url, map[string][]string{"level": {"info"}}))
+		So(err, ShouldBeNil)
+		So(mustJSONQ(c)(resp.String("level")), ShouldEqual, log.GetLevel().String())
+		So(log.GetLevel().String(), ShouldEqual, "info")
+		So(mustJSONQ(c)(resp.String("orig")), ShouldEqual, "fatal")
+		So(mustJSONQ(c)(resp.String("want")), ShouldEqual, "info")
+
+		// test invalid level
+		resp, err = parseResponse(http.PostForm(url, map[string][]string{"level": {"happy"}}))
+		So(err, ShouldBeNil)
+		So(mustJSONQ(c)(resp.String("level")), ShouldEqual, log.GetLevel().String())
+		So(log.GetLevel().String(), ShouldEqual, "info")
+		So(mustJSONQ(c)(resp.String("orig")), ShouldEqual, "info")
+		So(mustJSONQ(c)(resp.String("want")), ShouldEqual, "happy")
+		So(mustJSONQ(c)(resp.String("err")), ShouldNotBeEmpty)
+
+		// test empty level
+		resp, err = parseResponse(http.PostForm(url, nil))
+		So(err, ShouldBeNil)
+		So(mustJSONQ(c)(resp.String("level")), ShouldEqual, log.GetLevel().String())
+		So(log.GetLevel().String(), ShouldEqual, "info")
+		So(mustJSONQ(c)(resp.String("orig")), ShouldEqual, "info")
+
+		// test invalid query
+		rawResp, err := http.Head(url)
+		So(err, ShouldBeNil)
+		So(rawResp.StatusCode, ShouldEqual, http.StatusBadRequest)
+
+	})
+}
diff --git a/utils/signal.go b/utils/signal.go
new file mode 100644
index 000000000..c348d8ea1
--- /dev/null
+++ b/utils/signal.go
@@ -0,0 +1,35 @@
+/*
+ * Copyright 2019 The CovenantSQL Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package utils
+
+import (
+	"os"
+	"os/signal"
+	"syscall"
+)
+
+// WaitForExit waits for user cancellation signals: SIGINT/SIGTERM and ignore SIGHUP/SIGTTIN/SIGTTOU.
+func WaitForExit() <-chan os.Signal {
+	signalCh := make(chan os.Signal, 1)
+	signal.Notify(
+		signalCh,
+		syscall.SIGINT,
+		syscall.SIGTERM,
+	)
+	signal.Ignore(syscall.SIGHUP, syscall.SIGTTIN, syscall.SIGTTOU)
+	return signalCh
+}
diff --git a/xenomint/query_sanitizer.go b/xenomint/query_sanitizer.go
index 81119fede..25dc32c14 100644
--- a/xenomint/query_sanitizer.go
+++ b/xenomint/query_sanitizer.go
@@ -76,7 +76,7 @@ var (
 
 func convertQueryAndBuildArgs(pattern string, args []types.NamedArg) (containsDDL bool, p string, ifs []interface{}, err error) {
 	if lower := strings.ToLower(pattern); strings.Contains(lower, "begin") ||
-		strings.Contains(lower, "rollback") {
+		strings.Contains(lower, "rollback") || strings.Contains(lower, "commit") {
 		return false, pattern, nil, nil
 	}
 	var (
diff --git a/xenomint/state.go b/xenomint/state.go
index e7034a620..7bcbf5557 100644
--- a/xenomint/state.go
+++ b/xenomint/state.go
@@ -404,6 +404,11 @@ func (s *State) write(
 			}
 			defer s.executer.Exec(`ROLLBACK TO "?"`, lastSeq)
 		}
+		if s.level != sql.LevelReadUncommitted {
+			// NOTE(leventeliu): this will cancel any uncommitted transaction, and do not harm to
+			// committed ones.
+			defer s.executer.Exec(`ROLLBACK`)
+		}
 		for i, v := range req.Payload.Queries {
 			var res sql.Result
 			if res, ierr = s.writeSingle(ctx, &v); ierr != nil {
@@ -426,10 +431,6 @@ func (s *State) write(
 					return
 				}
 			}
-		} else {
-			// NOTE(leventeliu): this will cancel any uncommitted transaction, and do not harm to
-			// committed ones.
-			s.executer.Exec(`ROLLBACK`)
 		}
 		// Try to commit if the ongoing tx is too large or schema is changed
 		if s.getSeq()-s.getLastCommitPoint() > s.maxTx ||
diff --git a/xenomint/state_test.go b/xenomint/state_test.go
index 8c058d831..9811f38be 100644
--- a/xenomint/state_test.go
+++ b/xenomint/state_test.go
@@ -22,6 +22,7 @@ import (
 	"fmt"
 	"os"
 	"path"
+	"reflect"
 	"sync"
 	"testing"
 
@@ -702,6 +703,72 @@ func TestSerializableState(t *testing.T) {
 			_, resp, err = state.Query(req, true)
 			So(err, ShouldBeNil)
 			So(resp, ShouldNotBeNil)
+			Convey("The state should keep consistent with committed transaction", func(c C) {
+				var (
+					count         = 1000
+					insertQueries = make([]types.Query, count+2)
+					deleteQueries = make([]types.Query, count+2)
+					iReq, dReq    *types.Request
+				)
+				insertQueries[0] = buildQuery(`BEGIN`)
+				deleteQueries[0] = buildQuery(`BEGIN`)
+				for i := 0; i < count; i++ {
+					insertQueries[i+1] = buildQuery(
+						`INSERT INTO t1(k, v) VALUES (?, ?)`, i, fmt.Sprintf("v%d", i),
+					)
+					deleteQueries[i+1] = buildQuery(`DELETE FROM t1 WHERE k=?`, i)
+				}
+				insertQueries[count+1] = buildQuery(`COMMIT`)
+				deleteQueries[count+1] = buildQuery(`COMMIT`)
+				iReq = buildRequest(types.WriteQuery, insertQueries)
+				dReq = buildRequest(types.WriteQuery, deleteQueries)
+
+				var (
+					wg          = &sync.WaitGroup{}
+					ctx, cancel = context.WithCancel(context.Background())
+				)
+				defer func() {
+					cancel()
+					wg.Wait()
+				}()
+				wg.Add(1)
+				go func() {
+					defer wg.Done()
+					var (
+						resp *types.Response
+						err  error
+					)
+					for {
+						_, resp, err = state.Query(iReq, true)
+						c.So(err, ShouldBeNil)
+						c.Printf("insert affected rows: %d\n", resp.Header.AffectedRows)
+						_, resp, err = state.Query(dReq, true)
+						c.So(err, ShouldBeNil)
+						c.Printf("delete affected rows: %d\n", resp.Header.AffectedRows)
+						select {
+						case <-ctx.Done():
+							return
+						default:
+						}
+					}
+				}()
+
+				for i := 0; i < count; i++ {
+					_, resp, err = state.Query(buildRequest(types.ReadQuery, []types.Query{
+						buildQuery(`SELECT COUNT(1) AS cnt FROM t1`),
+					}), true)
+					So(reflect.DeepEqual(resp.Payload, types.ResponsePayload{
+						Columns:   []string{"cnt"},
+						DeclTypes: []string{""},
+						Rows:      []types.ResponseRow{{Values: []interface{}{int64(0)}}},
+					}) || reflect.DeepEqual(resp.Payload, types.ResponsePayload{
+						Columns:   []string{"cnt"},
+						DeclTypes: []string{""},
+						Rows:      []types.ResponseRow{{Values: []interface{}{int64(count)}}},
+					}), ShouldBeTrue)
+					Printf("index = %d, count = %v\n", i, resp)
+				}
+			})
 			Convey("The state should not see uncommitted changes", func(c C) {
 				// Build transaction query
 				var (
@@ -751,6 +818,82 @@ func TestSerializableState(t *testing.T) {
 					})
 				}
 			})
+			Convey("The state should see changes", FailureContinues, func(c C) {
+				// Build transaction query
+				var (
+					count   = 1000
+					queries = make([]types.Query, count+2)
+					req     *types.Request
+				)
+				queries[0] = buildQuery(`BEGIN`)
+				for i := 0; i < count; i++ {
+					queries[i+1] = buildQuery(
+						`INSERT INTO t1(k, v) VALUES (?, ?)`, i, fmt.Sprintf("v%d", i),
+					)
+				}
+				queries[count+1] = buildQuery(`COMMIT`)
+				req = buildRequest(types.WriteQuery, queries)
+				// Send uncommitted transaction on background
+				var _, resp, err = state.Query(req, true)
+				c.So(err, ShouldBeNil)
+				c.So(resp.Header.RowCount, ShouldEqual, 0)
+
+				// Test isolation level
+				for i := 0; i < count; i++ {
+					_, resp, err = state.Query(buildRequest(types.ReadQuery, []types.Query{
+						buildQuery(`SELECT COUNT(1) AS cnt FROM t1`),
+					}), true)
+					So(resp.Payload, ShouldResemble, types.ResponsePayload{
+						Columns:   []string{"cnt"},
+						DeclTypes: []string{""},
+						Rows:      []types.ResponseRow{{Values: []interface{}{int64(count)}}},
+					})
+				}
+
+				req = buildRequest(types.WriteQuery, []types.Query{
+					buildQuery("DELETE FROM t1"),
+				})
+				_, resp, err = state.Query(req, true)
+				c.So(err, ShouldBeNil)
+			})
+			Convey("The state should not see changes because of failure query content", FailureContinues, func(c C) {
+				// Build transaction query
+				var (
+					count   = 1000
+					queries = make([]types.Query, count+3)
+					req     *types.Request
+				)
+				queries[0] = buildQuery(`BEGIN`)
+				for i := 0; i < count; i++ {
+					queries[i+1] = buildQuery(
+						`INSERT INTO t1(k, v) VALUES (?, ?)`, i, fmt.Sprintf("v%d", i),
+					)
+				}
+				queries[count+1] = buildQuery(`HAHA`)
+				queries[count+2] = buildQuery(`COMMIT`)
+				req = buildRequest(types.WriteQuery, queries)
+				// Send uncommitted transaction on background
+				var _, resp, err = state.Query(req, true)
+				c.So(err, ShouldNotBeNil)
+
+				// Test isolation level
+				for i := 0; i < count; i++ {
+					_, resp, err = state.Query(buildRequest(types.ReadQuery, []types.Query{
+						buildQuery(`SELECT COUNT(1) AS cnt FROM t1`),
+					}), true)
+					So(resp.Payload, ShouldResemble, types.ResponsePayload{
+						Columns:   []string{"cnt"},
+						DeclTypes: []string{""},
+						Rows:      []types.ResponseRow{{Values: []interface{}{int64(0)}}},
+					})
+				}
+
+				req = buildRequest(types.WriteQuery, []types.Query{
+					buildQuery("DELETE FROM t1"),
+				})
+				_, resp, err = state.Query(req, true)
+				c.So(err, ShouldBeNil)
+			})
 		})
 	})
 }
diff --git a/xenomint/xxx_test.go b/xenomint/xxx_test.go
index a670fca3e..b0a7686d0 100644
--- a/xenomint/xxx_test.go
+++ b/xenomint/xxx_test.go
@@ -21,6 +21,7 @@ import (
 	"math/rand"
 	"os"
 	"path"
+	"runtime"
 	"sync"
 	"sync/atomic"
 	"syscall"
@@ -198,16 +199,18 @@ func setup() {
 
 	rand.Seed(time.Now().UnixNano())
 
-	// Set NOFILE limit
-	if err = syscall.Getrlimit(syscall.RLIMIT_NOFILE, &lmt); err != nil {
-		panic(err)
-	}
-	if lmt.Max < minNoFile {
-		panic("insufficient max RLIMIT_NOFILE")
-	}
-	lmt.Cur = lmt.Max
-	if err = syscall.Setrlimit(syscall.RLIMIT_NOFILE, &lmt); err != nil {
-		panic(err)
+	if runtime.GOOS == "linux" {
+		// Set NOFILE limit
+		if err = syscall.Getrlimit(syscall.RLIMIT_NOFILE, &lmt); err != nil {
+			panic(err)
+		}
+		if lmt.Max < minNoFile {
+			panic("insufficient max RLIMIT_NOFILE")
+		}
+		lmt.Cur = lmt.Max
+		if err = syscall.Setrlimit(syscall.RLIMIT_NOFILE, &lmt); err != nil {
+			panic(err)
+		}
 	}
 
 	// Initialze kms