在Spring Cloud Sleuth服務鏈路追蹤（Finchley版本）中，我們使用Spring Cloud Sleuth和zipkin的整合實現了服務鏈路的追蹤，但是遺憾的是鏈路資料儲存在記憶體中，無法持久化。zipkin的持久化可以結合Elasticsearch，MySQL實現。本節在Spring Cloud Sleuth服務鏈路追蹤（Finchley版本）的基礎上整合MySQL進行鏈路資料的持久化。本節示例工程如下：

在這裡我們只需對chainMonitor進行部分修改即可，其它服務不用做更改。

1.新增依賴支援mysql儲存鏈路資料

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
 
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>priv.simon</groupId>
    <artifactId>chainmonitor</artifactId>
    <
 
version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>chainmonitor</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <spring-cloud.version>Finchley.SR1</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <!-- zipkin 介面-->
        <dependency>
            <groupId>io.zipkin.java</groupId>
            <artifactId>zipkin-autoconfigure-ui</artifactId>
            <version>2.11.5</version>
        </dependency>
        <!-- zipkin 服務類-->
        <dependency>
            <groupId>io.zipkin.java</groupId>
            <artifactId>zipkin-server</artifactId>
            <version>2.11.5</version>
        </dependency>
        <dependency>
            <groupId>io.zipkin.java</groupId>
            <artifactId>zipkin-autoconfigure-storage-mysql</artifactId>
            <version>2.11.5</version>
        </dependency>
        <dependency>
            <groupId>io.zipkin.zipkin2</groupId>
            <artifactId>zipkin-storage-mysql-v1</artifactId>
            <version>2.11.5</version>
        </dependency>
        <dependency>
            <groupId>org.jooq</groupId>
            <artifactId>jooq</artifactId>
            <version>3.11.4</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!--dbcp2資料庫連線池-->
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-dbcp2</artifactId>
            <version>2.3.0</version>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

由於Spring Boot 2.0之後官方不再建議自定義zipkin，建議使用官方提供的zipkin.jar包，將springboot升級至2.0後，發現zipkin2使用mysql做日誌儲存會出錯，需要新增以下依賴：

<dependency>
    <groupId>org.jooq</groupId>
    <artifactId>jooq</artifactId>
    <version>3.11.4</version>
</dependency>

另外啟動的時候發現，zipkin使用Spring Boot 2.0 預設的資料庫連線池hikaricp會有問題，無法啟動，這裡改成了dbcp2資料庫連線池：

<!--dbcp2資料庫連線池-->
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-dbcp2</artifactId>
    <version>2.3.0</version>
</dependency>

2.配置檔案

server:
  port: 8770

spring:
  application:
    name: chainmonitor
  datasource:
    url: jdbc:mysql://localhost:3306/zipkin?autoReconnect=true&useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull&useSSL=false
    username: root
    password: 123456
    driver-class-name: com.mysql.jdbc.Driver
    initialization-mode: always
    continue-on-error: true
    schema: classpath:/zipkin.sql
    dbcp2:
      #初始化連線:連線池啟動時建立的初始化連線數量
      initial-size: 50
      #從連線池獲取一個連線時，最大的等待時間,連線池會等待N毫秒，等待不到，則丟擲異常
      max-wait-millis: 60000
      #最大空閒連線:連線池中容許保持空閒狀態的最大連線數量,超過的空閒連線將被釋放,如果設定為負數表示不限制
      max-idle: 100
      #通過這個池建立連線的預設自動提交狀態。如果不設定，則setAutoCommit 方法將不被呼叫
      default-auto-commit: true
      #通過這個池建立連線的預設只讀狀態
      default-read-only: false
      #指明在從池中租借物件時是否要進行驗證有效，如果物件驗證失敗，則物件將從池子釋放，然後我們將嘗試租借另一個
      test-on-borrow: true
    type: org.apache.commons.dbcp2.BasicDataSource
  jpa:
    database: mysql
    show-sql: true
    hibernate:
      ddl-auto: update
    properties:
      hibernate:
        dialect: org.hibernate.dialect.MySQL5Dialect
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/
management:
  metrics:
    web:
      server:
        auto-time-requests: false
zipkin:
  storage:
    type: mysql

zipkin持久化資料需要建立三張表用於儲存資料，這三張表會在服務啟動的時候建立。其中

spring:
  datasource:
    schema: classpath:/zipkin.sql

指定建立表的語句在資原始檔夾下。

3.sql語句

CREATE TABLE IF NOT EXISTS zipkin_spans (
  `trace_id_high` BIGINT NOT NULL DEFAULT 0 COMMENT 'If non zero, this means the trace uses 128 bit traceIds instead of 64 bit',
  `trace_id` BIGINT NOT NULL,
  `id` BIGINT NOT NULL,
  `name` VARCHAR(255) NOT NULL,
  `parent_id` BIGINT,
  `debug` BIT(1),
  `start_ts` BIGINT COMMENT 'Span.timestamp(): epoch micros used for endTs query and to implement TTL',
      `duration` BIGINT COMMENT 'Span.duration(): micros used for minDuration and maxDuration query'
) ENGINE=InnoDB ROW_FORMAT=COMPRESSED CHARACTER SET=utf8 COLLATE utf8_general_ci;

ALTER TABLE zipkin_spans ADD UNIQUE KEY(`trace_id_high`, `trace_id`, `id`) COMMENT 'ignore insert on duplicate';
ALTER TABLE zipkin_spans ADD INDEX(`trace_id_high`, `trace_id`, `id`) COMMENT 'for joining with zipkin_annotations';
ALTER TABLE zipkin_spans ADD INDEX(`trace_id_high`, `trace_id`) COMMENT 'for getTracesByIds';
ALTER TABLE zipkin_spans ADD INDEX(`name`) COMMENT 'for getTraces and getSpanNames';
ALTER TABLE zipkin_spans ADD INDEX(`start_ts`) COMMENT 'for getTraces ordering and range';

CREATE TABLE IF NOT EXISTS zipkin_annotations (
  `trace_id_high` BIGINT NOT NULL DEFAULT 0 COMMENT 'If non zero, this means the trace uses 128 bit traceIds instead of 64 bit',
  `trace_id` BIGINT NOT NULL COMMENT 'coincides with zipkin_spans.trace_id',
  `span_id` BIGINT NOT NULL COMMENT 'coincides with zipkin_spans.id',
  `a_key` VARCHAR(255) NOT NULL COMMENT 'BinaryAnnotation.key or Annotation.value if type == -1',
  `a_value` BLOB COMMENT 'BinaryAnnotation.value(), which must be smaller than 64KB',
  `a_type` INT NOT NULL COMMENT 'BinaryAnnotation.type() or -1 if Annotation',
  `a_timestamp` BIGINT COMMENT 'Used to implement TTL; Annotation.timestamp or zipkin_spans.timestamp',
  `endpoint_ipv4` INT COMMENT 'Null when Binary/Annotation.endpoint is null',
  `endpoint_ipv6` BINARY(16) COMMENT 'Null when Binary/Annotation.endpoint is null, or no IPv6 address',
  `endpoint_port` SMALLINT COMMENT 'Null when Binary/Annotation.endpoint is null',
  `endpoint_service_name` VARCHAR(255) COMMENT 'Null when Binary/Annotation.endpoint is null'
) ENGINE=InnoDB ROW_FORMAT=COMPRESSED CHARACTER SET=utf8 COLLATE utf8_general_ci;

ALTER TABLE zipkin_annotations ADD UNIQUE KEY(`trace_id_high`, `trace_id`, `span_id`, `a_key`, `a_timestamp`) COMMENT 'Ignore insert on duplicate';
ALTER TABLE zipkin_annotations ADD INDEX(`trace_id_high`, `trace_id`, `span_id`) COMMENT 'for joining with zipkin_spans';
ALTER TABLE zipkin_annotations ADD INDEX(`trace_id_high`, `trace_id`) COMMENT 'for getTraces/ByIds';
ALTER TABLE zipkin_annotations ADD INDEX(`endpoint_service_name`) COMMENT 'for getTraces and getServiceNames';
ALTER TABLE zipkin_annotations ADD INDEX(`a_type`) COMMENT 'for getTraces';
ALTER TABLE zipkin_annotations ADD INDEX(`a_key`) COMMENT 'for getTraces';
ALTER TABLE zipkin_annotations ADD INDEX(`trace_id`, `span_id`, `a_key`) COMMENT 'for dependencies job';

CREATE TABLE IF NOT EXISTS zipkin_dependencies (
  `day` DATE NOT NULL,
  `parent` VARCHAR(255) NOT NULL,
  `child` VARCHAR(255) NOT NULL,
  `call_count` BIGINT,
  `error_count` BIGINT
) ENGINE=InnoDB ROW_FORMAT=COMPRESSED CHARACTER SET=utf8 COLLATE utf8_general_ci;

ALTER TABLE zipkin_dependencies ADD UNIQUE KEY(`day`, `parent`, `child`);

4. 測試

1. 依次啟動服務：eureka->provider->consumer->chainMonitor,此時發現數據庫已經建立了三張表，並且chainMonitor訪問正常
   
2. 訪問provider或consumer服務，表中插入了資料
   
3. 重啟chainMonitor服務，可以查詢到鏈路資料，持久化成功
   

github下載示例程式碼