一、簡介

我們在上上一篇文章(https://blog.csdn.net/Weixiaohuai/article/details/82883280)已經實現了通過RabbitMQ訊息中介軟體的方式來收集服務鏈路跟蹤資訊，但是當zipkin-server服務端重啟之後，你會發現之前的鏈路資訊都清空了，通過zipkin視覺化介面已經不能看到服務之間的呼叫關係以及服務依賴關係了，這個時候我們就需要考慮將服務鏈路資訊進行持久化，通常都是儲存在資料庫或者搜尋引擎如ES中，本文將實現將服務鏈路跟蹤資訊儲存在Mysql資料庫中，從而實現鏈路資訊的持久化。

二、修改zipkin-server

【a】在zipkin-server的pom.xml中新增依賴

 <!--mysql資料庫配置-->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.25</version>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
 

【b】application.yml中新增資料庫配置、zipkin儲存方式等資訊，具體配置檔案如下

server:
  port: 2222
spring:
  application:
    name: zipkin-server
#RabbitMQ配置
  rabbitmq:
    port: 5672
    username: guest
    password: guest
    host: localhost
#資料庫配置
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/sleuth_zipkin_mysql?useUnicode=true&characterEncoding=utf8&useSSL=false
    username: root
    password: wsh0905
#當前程式不使用sleuth
  sleuth:
    enabled: false
#表示zipkin資料儲存方式是mysql
zipkin:
  storage:
    type: mysql
#服務註冊中心地址配置
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:1111/eureka/
 

【c】在資料庫中建立儲存鏈路資訊的相關表，主要有: 

zipkin_spans、zipkin_annotations、zipkin_dependencies三張表，具體sql:

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`);

通過改動zipkin server，這樣就可以實現mysql儲存鏈路資訊。

三、啟動專案

如圖，可以看到rabbitMQ成功收集了服務鏈路資訊。這時候我們查詢資料庫中相關表的資料，

由圖，我們已經實現了將鏈路資訊持久化到資料庫中。

四、總結

上面我們通過改造zipkin-server將服務鏈路跟蹤資訊儲存到資料庫中，當然，在實際專案中，也可以儲存在搜尋引擎(如ES中),

這需要根據具體專案規模以及專案需求來定，以上是作者在學習Spring Cloud Sleuth持久化鏈路資訊的一些總結以及方法，僅供大家參考，一起學習一起進步!