-背景前提

公司的MySQL数据库是分库分表的，若要是按照一个库（IP）对应一个实例的话，就需要创建10个实例，而且改动还很不方便，一次需要改10个配置文件。所以查到canal自带这种功能；

对于分库分表的MySQL配置的port，username，password，database，table都是一样的，这个是前提条件；

最好是用过配置过单实例的。

-修改canal.properties文件

开启group-instance.xml,注释其他的

# position info
canal.instance.master1.address=192.168.88.130:3306 #源库1的ip地址
canal.instance.master1.journal.name=
canal.instance.master1.position=
canal.instance.master1.timestamp=
canal.instance.master1.gtid=
 
canal.instance.master2.address=192.168.88.129:3306 #源库2的ip地址
canal.instance.master2.journal.name=
canal.instance.master2.position=
canal.instance.master2.timestamp=
canal.instance.master2.gtid=
 
canal.instance.master3.address=192.168.88.128:3306 #源库3的ip地址
canal.instance.master3.journal.name=
canal.instance.master3.position=
canal.instance.master3.timestamp=
canal.instance.master3.gtid=

-修改spring/group-instance.xml

<!-- 多个实例就添加 ，需要添加<ref bean="eventParser3" /> -->
<bean id="eventParser" class="com.alibaba.otter.canal.parse.inbound.group.GroupEventParser">
                <property name="eventParsers">
                        <list>
                                <ref bean="eventParser1" />
                                <ref bean="eventParser2" />
                                <ref bean="eventParser3" />
                        </list>
                </property>
        </bean>
 
<!-- 多个实例就添加 ，需要修改eventParser3，master3，standby3-->
<bean id="eventParser3" parent="baseEventParser">
                <property name="destination" value="${canal.instance.destination}" />
                <property name="slaveId" value="${canal.instance.mysql.slaveId:0}" />
                <!-- 心跳配置 -->
                <property name="detectingEnable" value="${canal.instance.detecting.enable:false}" />
                <property name="detectingSQL" value="${canal.instance.detecting.sql}" />
                <property name="detectingIntervalInSeconds" value="${canal.instance.detecting.interval.time:5}" />
                <property name="haController">
                        <bean class="com.alibaba.otter.canal.parse.ha.HeartBeatHAController">
                                <property name="detectingRetryTimes" value="${canal.instance.detecting.retry.threshold:3}" />
                                <property name="switchEnable" value="${canal.instance.detecting.heartbeatHaEnable:false}" />
                        </bean>
                </property>
 
                <property name="alarmHandler" ref="alarmHandler" />
 
                <!-- 解析过滤处理 -->
                <property name="eventFilter">
                        <bean class="com.alibaba.otter.canal.filter.aviater.AviaterRegexFilter" >
                                <constructor-arg index="0" value="${canal.instance.filter.regex:.*\..*}" />
                        </bean>
                </property>
 
                <property name="eventBlackFilter">
                        <bean class="com.alibaba.otter.canal.filter.aviater.AviaterRegexFilter" >
                                <constructor-arg index="0" value="${canal.instance.filter.black.regex:}" />
                                <constructor-arg index="1" value="false" />
                        </bean>
                </property>
 
                <property name="fieldFilter" value="${canal.instance.filter.field}" />
                <property name="fieldBlackFilter" value="${canal.instance.filter.black.field}" />
 
                <!-- 最大事务解析大小，超过该大小后事务将被切分为多个事务投递 -->
                <property name="transactionSize" value="${canal.instance.transaction.size:1024}" />
 
                <!-- 网络链接参数 -->
                <property name="receiveBufferSize" value="${canal.instance.network.receiveBufferSize:16384}" />
                <property name="sendBufferSize" value="${canal.instance.network.sendBufferSize:16384}" />
                <property name="defaultConnectionTimeoutInSeconds" value="${canal.instance.network.soTimeout:30}" />
 
                <!-- 解析编码 -->
                <!-- property name="connectionCharsetNumber" value="${canal.instance.connectionCharsetNumber:33}" /-->
                <property name="connectionCharset" value="${canal.instance.connectionCharset:UTF-8}" />
 
                <!-- 解析位点记录 -->
                <property name="logPositionManager">
                        <bean class="com.alibaba.otter.canal.parse.index.MemoryLogPositionManager" />
                </property>
 
                <!-- failover切换时回退的时间 -->
                <property name="fallbackIntervalInSeconds" value="${canal.instance.fallbackIntervalInSeconds:60}" />
 
                <!-- 解析数据库信息 -->
                <property name="masterInfo">
                        <bean class="com.alibaba.otter.canal.parse.support.AuthenticationInfo" init-method="initPwd">
                                <property name="address" value="${canal.instance.master3.address}" />
                                <property name="username" value="${canal.instance.dbUsername:retl}" />
                                <property name="password" value="${canal.instance.dbPassword:retl}" />
                                <property name="pwdPublicKey" value="${canal.instance.pwdPublicKey:retl}" />
                                <property name="enableDruid" value="${canal.instance.enableDruid:false}" />
                                <property name="defaultDatabaseName" value="${canal.instance.defaultDatabaseName:}" />
                        </bean>
                </property>
                <property name="standbyInfo">
                        <bean class="com.alibaba.otter.canal.parse.support.AuthenticationInfo" init-method="initPwd">
                                <property name="address" value="${canal.instance.standby3.address}" />
                                <property name="username" value="${canal.instance.dbUsername:retl}" />
                                <property name="password" value="${canal.instance.dbPassword:retl}" />
                                <property name="pwdPublicKey" value="${canal.instance.pwdPublicKey:retl}" />
                                <property name="enableDruid" value="${canal.instance.enableDruid:false}" />
                                <property name="defaultDatabaseName" value="${canal.instance.defaultDatabaseName:}" />
                        </bean>
                </property>
 
                <!-- 解析起始位点 -->
                <property name="masterPosition">
                        <bean class="com.alibaba.otter.canal.protocol.position.EntryPosition">
                                <property name="journalName" value="${canal.instance.master3.journal.name}" />
                                <property name="position" value="${canal.instance.master3.position}" />
                                <property name="timestamp" value="${canal.instance.master3.timestamp}" />
                                <property name="gtid" value="${canal.instance.master3.gtid}" />
                        </bean>
                </property>
                <property name="standbyPosition">
                        <bean class="com.alibaba.otter.canal.protocol.position.EntryPosition">
                                <property name="journalName" value="${canal.instance.standby3.journal.name}" />
                                <property name="position" value="${canal.instance.standby3.position}" />
                                <property name="timestamp" value="${canal.instance.standby3.timestamp}" />
                                <property name="gtid" value="${canal.instance.standby3.gtid}" />
                        </bean>
                </property>
                <property name="filterQueryDml" value="${canal.instance.filter.query.dml:false}" />
                <property name="filterQueryDcl" value="${canal.instance.filter.query.dcl:false}" />
                <property name="filterQueryDdl" value="${canal.instance.filter.query.ddl:false}" />
                <property name="useDruidDdlFilter" value="${canal.instance.filter.druid.ddl:true}" />
                <property name="filterTableError" value="${canal.instance.filter.table.error:false}" />
                <property name="supportBinlogFormats" value="${canal.instance.binlog.format}" />
                <property name="supportBinlogImages" value="${canal.instance.binlog.image}" />
 
                <!-- parallel parser -->
                <property name="parallel" value="${canal.instance.parser.parallel:true}" />
                <property name="parallelThreadSize" value="${canal.instance.parser.parallelThreadSize}" />
                <property name="parallelBufferSize" value="${canal.instance.parser.parallelBufferSize:256}" />
        </bean>

需要修改的：添加<ref bean="eventParser3" /> 、eventParser3、master3、standby3