（一）简介
默认情况下，Zipkin Server 会将跟踪信息存储在内存中，每次重启 Zipkin Server 都会使之前收集的跟踪信息丢失，并且当有大量跟踪信息时，内存存储也会造成性能瓶颈，所以通常我们都需要将跟踪信息存储到外部组件中，如 Mysql。
由于 Spring Boot 2.0 之后 Zipkin 不再推荐我们来自定义 Server 端了，那么如何把 Zipkin Server 修改为 Mysql 存储功能呢？答案还是和集成 RabbitMQ 一样，在启动 zipkin.jar 的时候，配置相关参数
（二）配置 zipkin server
2.1 创建数据库、表信息
既然数据存储改为 Mysql，那么肯定要建立相关的表，建表的脚本文件 mysql.sql 在 GitHub 官方地址能查到，链接如下：
https://github.com/openzipkin/zipkin/blob/master/zipkin-storage/mysql-v1/src/main/resources/mysql.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,`remote_service_name` VARCHAR(255),`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',PRIMARY KEY (`trace_id_high`, `trace_id`, `id`)
) ENGINE=InnoDB ROW_FORMAT=COMPRESSED CHARACTER SET=utf8 COLLATE utf8_general_ci;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(`remote_service_name`) COMMENT 'for getTraces and getRemoteServiceNames';
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 and autocomplete values';
ALTER TABLE zipkin_annotations ADD INDEX(`a_key`) COMMENT 'for getTraces and autocomplete values';
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,PRIMARY KEY (`day`, `parent`, `child`)
) ENGINE=InnoDB ROW_FORMAT=COMPRESSED CHARACTER SET=utf8 COLLATE utf8_general_ci;这里会创建三张表，如下，具体表结构信息，大家可以自己查看
2.2 启动 zipkin
zipkin.jar 的 配置文件内容可以查看 GitHub 上官方的提供
https://github.com/openzipkin/zipkin/blob/master/zipkin-server/src/main/resources/zipkin-server-shared.yml
为了方便，我在这里展示部分内容：
zipkin:collector:rabbitmq:# RabbitMQ server address list (comma-separated list of host:port)addresses: ${RABBIT_ADDRESSES:}concurrency: ${RABBIT_CONCURRENCY:1}# TCP connection timeout in millisecondsconnection-timeout: ${RABBIT_CONNECTION_TIMEOUT:60000}password: ${RABBIT_PASSWORD:guest}queue: ${RABBIT_QUEUE:zipkin}username: ${RABBIT_USER:guest}virtual-host: ${RABBIT_VIRTUAL_HOST:/}useSsl: ${RABBIT_USE_SSL:false}uri: ${RABBIT_URI:}storage:strict-trace-id: ${STRICT_TRACE_ID:true}search-enabled: ${SEARCH_ENABLED:true}type: ${STORAGE_TYPE:mem}mem:# Maximum number of spans to keep in memory. When exceeded, oldest traces (and their spans) will be purged.# A safe estimate is 1K of memory per span (each span with 2 annotations + 1 binary annotation), plus# 100 MB for a safety buffer. You'll need to verify in your own environment.# Experimentally, it works with: max-spans of 500000 with JRE argument -Xmx600m.max-spans: 500000cassandra:# Comma separated list of host addresses part of Cassandra cluster. Ports default to 9042 but you can also specify a custom port with 'host:port'.contact-points: ${CASSANDRA_CONTACT_POINTS:localhost}# Name of the datacenter that will be considered "local" for latency load balancing. When unset, load-balancing is round-robin.local-dc: ${CASSANDRA_LOCAL_DC:}# Will throw an exception on startup if authentication fails.username: ${CASSANDRA_USERNAME:}password: ${CASSANDRA_PASSWORD:}keyspace: ${CASSANDRA_KEYSPACE:zipkin}# Max pooled connections per datacenter-local host.max-connections: ${CASSANDRA_MAX_CONNECTIONS:8}# Ensuring that schema exists, if enabled tries to execute script /zipkin-cassandra-core/resources/cassandra-schema-cql3.txt.ensure-schema: ${CASSANDRA_ENSURE_SCHEMA:true}# 7 days in secondsspan-ttl: ${CASSANDRA_SPAN_TTL:604800}# 3 days in secondsindex-ttl: ${CASSANDRA_INDEX_TTL:259200}# the maximum trace index metadata entries to cacheindex-cache-max: ${CASSANDRA_INDEX_CACHE_MAX:100000}# how long to cache index metadata about a trace. 1 minute in secondsindex-cache-ttl: ${CASSANDRA_INDEX_CACHE_TTL:60}# how many more index rows to fetch than the user-supplied query limitindex-fetch-multiplier: ${CASSANDRA_INDEX_FETCH_MULTIPLIER:3}# Using ssl for connection, rely on Keystoreuse-ssl: ${CASSANDRA_USE_SSL:false}cassandra3:# Comma separated list of host addresses part of Cassandra cluster. Ports default to 9042 but you can also specify a custom port with 'host:port'.contact-points: ${CASSANDRA_CONTACT_POINTS:localhost}# Name of the datacenter that will be considered "local" for latency load balancing. When unset, load-balancing is round-robin.local-dc: ${CASSANDRA_LOCAL_DC:}# Will throw an exception on startup if authentication fails.username: ${CASSANDRA_USERNAME:}password: ${CASSANDRA_PASSWORD:}keyspace: ${CASSANDRA_KEYSPACE:zipkin2}# Max pooled connections per datacenter-local host.max-connections: ${CASSANDRA_MAX_CONNECTIONS:8}# Ensuring that schema exists, if enabled tries to execute script /zipkin2-schema.cqlensure-schema: ${CASSANDRA_ENSURE_SCHEMA:true}# how many more index rows to fetch than the user-supplied query limitindex-fetch-multiplier: ${CASSANDRA_INDEX_FETCH_MULTIPLIER:3}# Using ssl for connection, rely on Keystoreuse-ssl: ${CASSANDRA_USE_SSL:false}elasticsearch:# host is left unset intentionally, to defer the decisionhosts: ${ES_HOSTS:}pipeline: ${ES_PIPELINE:}max-requests: ${ES_MAX_REQUESTS:64}timeout: ${ES_TIMEOUT:10000}index: ${ES_INDEX:zipkin}date-separator: ${ES_DATE_SEPARATOR:-}index-shards: ${ES_INDEX_SHARDS:5}index-replicas: ${ES_INDEX_REPLICAS:1}username: ${ES_USERNAME:}password: ${ES_PASSWORD:}http-logging: ${ES_HTTP_LOGGING:}legacy-reads-enabled: ${ES_LEGACY_READS_ENABLED:true}mysql:host: ${MYSQL_HOST:localhost}port: ${MYSQL_TCP_PORT:3306}username: ${MYSQL_USER:}password: ${MYSQL_PASS:}db: ${MYSQL_DB:zipkin}max-active: ${MYSQL_MAX_CONNECTIONS:10}use-ssl: ${MYSQL_USE_SSL:false}ui:enabled: ${QUERY_ENABLED:true}## Values below here are mapped to ZipkinUiProperties, served as /config.json# Default limit for Find Tracesquery-limit: 10# The value here becomes a label in the top-right cornerenvironment:# Default duration to look back when finding traces.# Affects the "Start time" element in the UI. 1 hour in millisdefault-lookback: 3600000# When false, disables the "find a trace" screensearch-enabled: ${SEARCH_ENABLED:true}# Which sites this Zipkin UI covers. Regex syntax. (e.g. http:\/\/example.com\/.*)# Multiple sites can be specified, e.g.# - .*example1.com# - .*example2.com# Default is "match all websites"instrumented: .*# URL placed into the <base> tag in the HTMLbase-path: /zipkin
从它的配置文件可以看出，storage 默认采用的是内存存储，所以我们要设置 zipkin.storage.type=mysql，除此之外还要设置 zipkin.storage.mysql.host、port、username、password、db 等
下面贴出我的启动命令：
java -jar zipkin.jar --zipkin.collector.rabbitmq.addresses=localhost --zipkin.storage.type=mysql
--zipkin.storage.mysql.host=localhost --zipkin.storage.mysql.port=3306 --zipkin.storage.mysql.username=root
--zipkin.storage.mysql.password=mysql --zipkin.storage.mysql.db=zipkin大家可以根据自己的数据库信息，修改相关配置即可
（三）验证
至于 Zipkin Client 端，是不需要相关修改的，按照上面命令启动 zipkin 后，访问 http://localhost:8481/service1，查看数据库信息，表 zipkin_annotations 和表 zipkin_spans 中已经数据存储了
表 zipkin_annotations ：
表 zipkin_spans ：
表中所存储的信息我们已经非常熟悉，之前分析的内容都可以在这两张表中体现出来。
从 GitHub 的官方配置文件中，我们可以看到，Zipkin 在存储方面除了对 Mysql 有扩展组件之外，还实现了对 CassCassandra 和 ElasElasticSearch 的支持扩展，具体的整合方式与 Mysql 的整合类似。
源码下载：https://github.com/shmilyah/spring-cloud-componets