当 Debezium 作为 kafka connect 中的源运行时,如果在该目标 MySQL 数据库(Amazon RDS 实例)上一段时间没有发生更新,那么一段时间后我会出现以下错误。
[2018-04-25 21:30:14,526] INFO Step 0: Get all known binlogs from MySQL (io.debezium.connector.mysql.MySqlConnectorTask:310)
[2018-04-25 21:30:14,536] INFO Connector requires binlog file 'mysql-bin-changelog.002640', but MySQL only has mysql-bin-changelog.002663, mysql-bin-changelog.002664, mysql-bin-changelog.002665 (io.debezium.connector.mysql.MySqlConnectorTask:323)
[2018-04-25 21:30:14,536] INFO MySQL has the binlog file 'mysql-bin-changelog.002640' required by the connector (io.debezium.connector.mysql.MySqlConnectorTask:325)
[2018-04-25 21:30:14,536] INFO Stopping MySQL connector task (io.debezium.connector.mysql.MySqlConnectorTask:239)
[2018-04-25 21:30:14,536] INFO WorkerSourceTask{id=swiggy-connector-0} Committing offsets (org.apache.kafka.connect.runtime.WorkerSourceTask:328)
[2018-04-25 21:30:14,536] INFO WorkerSourceTask{id=swiggy-connector-0} flushing 0 outstanding messages for offset commit (org.apache.kafka.connect.runtime.WorkerSourceTask:345)
[2018-04-25 21:30:14,536] ERROR WorkerSourceTask{id=swiggy-connector-0} Task threw an uncaught and unrecoverable exception (org.apache.kafka.connect.runtime.WorkerTask:172)
org.apache.kafka.connect.errors.ConnectException: The connector is trying to read binlog starting at binlog file 'mysql-bin-changelog.002640', pos=470, skipping 4 events plus 0 rows, but this is no longer available on the server. Reconfigure the connector to use a snapshot when needed.
at io.debezium.connector.mysql.MySqlConnectorTask.start(MySqlConnectorTask.java:117)
at io.debezium.connector.common.BaseSourceTask.start(BaseSourceTask.java:45)
at org.apache.kafka.connect.runtime.WorkerSourceTask.execute(WorkerSourceTask.java:164)
at org.apache.kafka.connect.runtime.WorkerTask.doRun(WorkerTask.java:170)
at org.apache.kafka.connect.runtime.WorkerTask.run(WorkerTask.java:214)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
当我去数据库并检查 MySQL 中的二进制日志时
mysql> show binary logs;
+----------------------------+-----------+
| Log_name | File_size |
+----------------------------+-----------+
| mysql-bin-changelog.002664 | 479 |
| mysql-bin-changelog.002665 | 120 |
+----------------------------+-----------+
mysql> show binlog events;
+----------------------------+-----+-------------+------------+-------------+---------------------------------------------------------------------------------------------------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+----------------------------+-----+-------------+------------+-------------+---------------------------------------------------------------------------------------------------------------------------------+
| mysql-bin-changelog.002664 | 4 | Format_desc | 1550192458 | 120 | Server ver: 5.6.39-log, Binlog ver: 4 |
| mysql-bin-changelog.002664 | 120 | Query | 1550192458 | 201 | BEGIN |
| mysql-bin-changelog.002664 | 201 | Query | 1550192458 | 391 | use `mysql`; INSERT INTO mysql.rds_heartbeat2(id, value) values (1,1524671965007) ON DUPLICATE KEY UPDATE value = 1524671965007 |
| mysql-bin-changelog.002664 | 391 | Xid | 1550192458 | 422 | COMMIT /* xid=308462 */ |
| mysql-bin-changelog.002664 | 422 | Rotate | 1550192458 | 479 | mysql-bin-changelog.002665;pos=4 |
+----------------------------+-----+-------------+------------+-------------+---------------------------------------------------------------------------------------------------------------------------------+
问题:
- 为什么Debezium闲置?为什么它在 002640 文件之后没有从 MySQL 读取文件?
这未被任何服务使用。因此,在 Debezium 能够读取之前,不可能有太多写入发生的情况。 - 没有任何活动发生时,为什么Amazon MySQL RDS会删除 binlog 文件?
这是一个测试数据库,只有我在其中插入记录。所以这里没有发生外部应用程序活动。 - 有没有办法恢复Debezium连接器并从 MySQL 当前可用的时间日志开始处理记录?(如果我对丢失的未读记录没意见)。
我尝试重新启动作业,删除和添加连接器,但我总是以同样的错误告终。
恢复活动的唯一解决方案- 删除 Kafka Connect 的offet 主题。
- 再次删除并添加 debezium 连接器。
我想要一种不同的方法,因为在生产中我们将拥有大量使用相同偏移主题的连接器。所以删除是不可能的。