我想要在SpringBoot中采用一种与业务代码解耦合的方式，来实现数据的变更记录，记录的内容是新数据，如果是更新操作还得有旧数据内容。
经过调研发现，使用Canal来监听MySQL的binlog变化可以实现这个需求，可是在监听到变化后需要马上保存变更记录，除非再做一些逻辑处理，于是我又结合了RabbitMQ来处理保存变更记录的操作。
环境搭建基于docker-compose：
version: "3"
services:
mysql:
network_mode: mynetwork
container_name: mymysql
ports:
- 3306:3306
restart: always
volumes:
- /etc/localtime:/etc/localtime
- /home/mycontainers/mymysql/data:/data
- /home/mycontainers/mymysql/mysql:/var/lib/mysql
- /home/mycontainers/mymysql/conf:/etc/mysql
environment:
- MYSQL_ROOT_PASSWORD=root
command:
--character-set-server=utf8mb4
--collation-server=utf8mb4_unicode_ci
--log-bin=/var/lib/mysql/mysql-bin
--server-id=1
--binlog-format=ROW
--expire_logs_days=7
--max_binlog_size=500M
image: mysql:5.7.20
rabbitmq:
container_name: myrabbit
ports:
- 15672:15672
- 5672:5672
restart: always
volumes:
- /etc/localtime:/etc/localtime
- /home/mycontainers/myrabbit/rabbitmq:/var/lib/rabbitmq
network_mode: mynetwork
environment:
- RABBITMQ_DEFAULT_USER=admin
- RABBITMQ_DEFAULT_PASS=123456
image: rabbitmq:3.8-management
canal-server:
container_name: canal-server
restart: always
ports:
- 11110:11110
- 11111:11111
- 11112:11112
volumes:
- /home/mycontainers/canal-server/conf/canal.properties:/home/admin/canal-server/conf/canal.properties
- /home/mycontainers/canal-server/conf/instance.properties:/home/admin/canal-server/conf/example/instance.properties
- /home/mycontainers/canal-server/logs:/home/admin/canal-server/logs
network_mode: mynetwork
depends_on:
- mysql
- rabbitmq
# - canal-admin
image: canal/canal-server:v1.1.5
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我们需要修改下Canal环境的配置文件：canal.properties和instance.properties，映射Canal中的以下两个路径：
/home/admin/canal-server/conf/canal.properties
配置文件中，canal.destinations意思是server上部署的instance列表，
/home/admin/canal-server/conf/example/instance.properties
这里的/example是指instance即实例名，要和上面canal.properties内instance配置对应，canal会为实例创建对应的文件夹，一个Client对应一个实例
以下是我们需要准备的两个配置文件具体内容：
########################################################## common argument ############################################################### tcp bind ip
canal.ip =
# register ip to zookeepercanal.register.ip =
canal.port = 11111
canal.metrics.pull.port = 11112
# canal instance user/passwd# canal.user = canal# canal.passwd = E3619321C1A937C46A0D8BD1DAC39F93B27D4458
# canal admin config# canal.admin.manager = canal-admin:8089
# canal.admin.port = 11110# canal.admin.user = admin# canal.admin.passwd = 6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9
# admin auto register 自动注册# canal.admin.register.auto = true# 集群名，单机则不写# canal.admin.register.cluster =# Canal Server 名字# canal.admin.register.name = canal-admin
canal.zkServers =
# flush data to zkcanal.zookeeper.flush.period = 1000
canal.withoutNetty = false
# tcp, kafka, rocketMQ, rabbitMQ, pulsarMQcanal.serverMode = tcp
# flush meta cursor/parse position to filecanal.file.data.dir = ${canal.conf.dir}
canal.file.flush.period = 1000
## memory store RingBuffer size, should be Math.pow(2,n)canal.instance.memory.buffer.size = 16384
## memory store RingBuffer used memory unit size , default 1kbcanal.instance.memory.buffer.memunit = 1024
## meory store gets mode used MEMSIZE or ITEMSIZEcanal.instance.memory.batch.mode = MEMSIZE
canal.instance.memory.rawEntry = true
## detecing configcanal.instance.detecting.enable = false
#canal.instance.detecting.sql = insert into retl.xdual values(1,now()) on duplicate key update x=now()canal.instance.detecting.sql = select 1
canal.instance.detecting.interval.time = 3
canal.instance.detecting.retry.threshold = 3
canal.instance.detecting.heartbeatHaEnable = false
# support maximum transaction size, more than the size of the transaction will be cut into multiple transactions deliverycanal.instance.transaction.size = 1024
# mysql fallback connected to new master should fallback timescanal.instance.fallbackIntervalInSeconds = 60
# network configcanal.instance.network.receiveBufferSize = 16384
canal.instance.network.sendBufferSize = 16384
canal.instance.network.soTimeout = 30
# binlog filter configcanal.instance.filter.druid.ddl = true
canal.instance.filter.query.dcl = false
canal.instance.filter.query.dml = false
canal.instance.filter.query.ddl = false
canal.instance.filter.table.error = false
canal.instance.filter.rows = false
canal.instance.filter.transaction.entry = false
canal.instance.filter.dml.insert = false
canal.instance.filter.dml.update = false
canal.instance.filter.dml.delete = false
# binlog format/image checkcanal.instance.binlog.format = ROW,STATEMENT,MIXED
canal.instance.binlog.image = FULL,MINIMAL,NOBLOB
# binlog ddl isolationcanal.instance.get.ddl.isolation = false
# parallel parser configcanal.instance.parser.parallel = true
## concurrent thread number, default 60% available processors, suggest not to exceed Runtime.getRuntime().availableProcessors()canal.instance.parser.parallelThreadSize = 16
## disruptor ringbuffer size, must be power of 2canal.instance.parser.parallelBufferSize = 256
# table meta tsdb infocanal.instance.tsdb.enable = true
canal.instance.tsdb.dir = ${canal.file.data.dir:../conf}/${canal.instance.destination:}
canal.instance.tsdb.url = jdbc:h2:${canal.instance.tsdb.dir}/h2;CACHE_SIZE=1000;MODE=MYSQL;canal.instance.tsdb.dbUsername = canal
canal.instance.tsdb.dbPassword = canal
# dump snapshot interval, default 24 hourcanal.instance.tsdb.snapshot.interval = 24
# purge snapshot expire , default 360 hour(15 days)canal.instance.tsdb.snapshot.expire = 360
########################################################## destinations ##############################################################canal.destinations = canal-exchange
# conf root dircanal.conf.dir = ../conf
# auto scan instance dir add/remove and start/stop instancecanal.auto.scan = true
canal.auto.scan.interval = 5
# set this value to 'true' means that when binlog pos not found, skip to latest.# WARN: pls keep 'false' in production env, or if you know what you want.canal.auto.reset.latest.pos.mode = false
canal.instance.tsdb.spring.xml = classpath:spring/tsdb/h2-tsdb.xml
#canal.instance.tsdb.spring.xml = classpath:spring/tsdb/mysql-tsdb.xml
canal.instance.global.mode = spring
canal.instance.global.lazy = false
canal.instance.global.manager.address = ${canal.admin.manager}
#canal.instance.global.spring.xml = classpath:spring/memory-instance.xmlcanal.instance.global.spring.xml = classpath:spring/file-instance.xml
#canal.instance.global.spring.xml = classpath:spring/default-instance.xml
########################################################### MQ Properties ################################################################ aliyun ak/sk , support rds/mqcanal.aliyun.accessKey =
canal.aliyun.secretKey =
canal.aliyun.uid=
canal.mq.flatMessage = true
canal.mq.canalBatchSize = 50
canal.mq.canalGetTimeout = 100
# Set this value to "cloud", if you want open message trace feature in aliyun.canal.mq.accessChannel = local
canal.mq.database.hash = true
canal.mq.send.thread.size = 30
canal.mq.build.thread.size = 8
########################################################### Kafka ###############################################################kafka.bootstrap.servers = 127.0.0.1:9092
kafka.acks = all
kafka.compression.type = none
kafka.batch.size = 16384
kafka.linger.ms = 1
kafka.max.request.size = 1048576
kafka.buffer.memory = 33554432
kafka.max.in.flight.requests.per.connection = 1
kafka.retries = 0
kafka.kerberos.enable = false
kafka.kerberos.krb5.file = "../conf/kerberos/krb5.conf"
kafka.kerberos.jaas.file = "../conf/kerberos/jaas.conf"
########################################################### RocketMQ ###############################################################rocketmq.producer.group = test
rocketmq.enable.message.trace = false
rocketmq.customized.trace.topic =
rocketmq.namespace =
rocketmq.namesrv.addr = 127.0.0.1:9876
rocketmq.retry.times.when.send.failed = 0
rocketmq.vip.channel.enabled = false
rocketmq.tag =
########################################################### RabbitMQ ###############################################################rabbitmq.host = myrabbit
rabbitmq.virtual.host = /
rabbitmq.exchange = canal-exchange
rabbitmq.username = admin
rabbitmq.password = RabbitMQ密码
rabbitmq.deliveryMode =
########################################################### Pulsar ###############################################################pulsarmq.serverUrl =
pulsarmq.roleToken =
pulsarmq.topicTenantPrefix =
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此时canal.serverMode = tcp，即TCP直连，我们先开启这个服务，然后手写Java客户端代码去连接它，等下再改为RabbitMQ。
通过注释可以看到，canal支持的服务模式有：tcp, kafka, rocketMQ, rabbitMQ, pulsarMQ，即主流的消息队列都支持。