調試一個程序， 調試到一半， 下班回家， 程序卡在了某一行， 第二天早上回來一看， 發現了異常：
Wed Sep 18 09:51:00 GMT+08:00 2019 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification. Wed Sep 18 09:51:00 GMT+08:00 2019 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification. 2019-09-18 09:51:00.722 [pool-3-thread-1] ERROR com.alibaba.druid.pool.DruidDataSource - discard connection com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 90 milliseconds ago. The last packet sent successfully to the server was 43,603,303 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:989) at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3743) at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2506) at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2677) at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2545) at com.mysql.jdbc.StatementImpl.executeSimpleNonQuery(StatementImpl.java:1453) at com.mysql.jdbc.RowDataDynamic.close(RowDataDynamic.java:178) at com.mysql.jdbc.ResultSetImpl.realClose(ResultSetImpl.java:6692) at com.mysql.jdbc.ResultSetImpl.close(ResultSetImpl.java:851) at com.alibaba.druid.pool.DruidPooledResultSet.close(DruidPooledResultSet.java:87) at com.alibaba.otter.canal.client.adapter.support.Util.sqlRS(Util.java:42) at com.alibaba.otter.canal.client.adapter.es.service.ESSyncService.subTableSimpleFieldOperation(ESSyncService.java:602) at com.alibaba.otter.canal.client.adapter.es.service.ESSyncService.update(ESSyncService.java:302) at com.alibaba.otter.canal.client.adapter.es.service.ESSyncService.sync(ESSyncService.java:95) at com.alibaba.otter.canal.client.adapter.es.service.ESSyncService.sync(ESSyncService.java:58) at com.alibaba.otter.canal.client.adapter.es.ESAdapter.sync(ESAdapter.java:172) at com.alibaba.otter.canal.client.adapter.es.ESAdapter.sync(ESAdapter.java:151) at com.alibaba.otter.canal.adapter.launcher.loader.AbstractCanalAdapterWorker.batchSync(AbstractCanalAdapterWorker.java:201) at com.alibaba.otter.canal.adapter.launcher.loader.AbstractCanalAdapterWorker.lambda$null$1(AbstractCanalAdapterWorker.java:62) at java.util.ArrayList.forEach(ArrayList.java:1257) at com.alibaba.otter.canal.adapter.launcher.loader.AbstractCanalAdapterWorker.lambda$null$2(AbstractCanalAdapterWorker.java:58) at java.util.concurrent.FutureTask.run$$$capture(FutureTask.java:266) at java.util.concurrent.FutureTask.run(FutureTask.java) 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) Caused by: java.net.SocketException: Software caused connection abort: socket write error at java.net.SocketOutputStream.socketWrite0(Native Method) at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:111) at java.net.SocketOutputStream.write(SocketOutputStream.java:155) at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82) at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140) at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3725) ... 24 common frames omitted 2019-09-18 09:51:00.867 [pool-3-thread-1] ERROR com.alibaba.otter.canal.client.adapter.support.Util - sqlRs has error, sql: SELECT * FROM (SELECT user_id, group_concat(label ORDER BY id DESC SEPARATOR ';') AS labels FROM label GROUP BY user_id) c WHERE c.user_id=3 2019-09-18 09:51:00.867 [pool-3-thread-1] ERROR c.a.otter.canal.client.adapter.es.service.ESSyncService - sync error, es index: erdp-join, DML : Dml{destination='example', database='elppmdb', table='label', type='UPDATE', es=1568727199000, ts=1568727199765, sql='', data=[{id=5, user_id=3, name=ttt, label=lab-rst, c_time=2019-09-17 21:33:19.0}], old=[{label=lab-rs, c_time=2019-09-17 19:10:04.0}]} 2019-09-18 09:51:00.923 [pool-3-thread-1] ERROR c.a.o.canal.adapter.launcher.loader.CanalAdapterWorker - java.lang.RuntimeException: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 90 milliseconds ago. The last packet sent successfully to the server was 43,603,303 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem. java.lang.RuntimeException: java.lang.RuntimeException: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 90 milliseconds ago. The last packet sent successfully to the server was 43,603,303 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem. at com.alibaba.otter.canal.client.adapter.es.service.ESSyncService.sync(ESSyncService.java:110) at com.alibaba.otter.canal.client.adapter.es.service.ESSyncService.sync(ESSyncService.java:58) at com.alibaba.otter.canal.client.adapter.es.ESAdapter.sync(ESAdapter.java:172) at com.alibaba.otter.canal.client.adapter.es.ESAdapter.sync(ESAdapter.java:151) at com.alibaba.otter.canal.adapter.launcher.loader.AbstractCanalAdapterWorker.batchSync(AbstractCanalAdapterWorker.java:201) at com.alibaba.otter.canal.adapter.launcher.loader.AbstractCanalAdapterWorker.lambda$null$1(AbstractCanalAdapterWorker.java:62) at java.util.ArrayList.forEach(ArrayList.java:1257) at com.alibaba.otter.canal.adapter.launcher.loader.AbstractCanalAdapterWorker.lambda$null$2(AbstractCanalAdapterWorker.java:58) at java.util.concurrent.FutureTask.run$$$capture(FutureTask.java:266) at java.util.concurrent.FutureTask.run(FutureTask.java) 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) Caused by: java.lang.RuntimeException: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 90 milliseconds ago. The last packet sent successfully to the server was 43,603,303 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem. at com.alibaba.otter.canal.client.adapter.support.Util.sqlRS(Util.java:45) at com.alibaba.otter.canal.client.adapter.es.service.ESSyncService.subTableSimpleFieldOperation(ESSyncService.java:602) at com.alibaba.otter.canal.client.adapter.es.service.ESSyncService.update(ESSyncService.java:302) at com.alibaba.otter.canal.client.adapter.es.service.ESSyncService.sync(ESSyncService.java:95) ... 12 common frames omitted Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 90 milliseconds ago. The last packet sent successfully to the server was 43,603,303 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:989) at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3743) at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2506) at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2677) at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2545) at com.mysql.jdbc.StatementImpl.executeSimpleNonQuery(StatementImpl.java:1453) at com.mysql.jdbc.RowDataDynamic.close(RowDataDynamic.java:178) at com.mysql.jdbc.ResultSetImpl.realClose(ResultSetImpl.java:6692) at com.mysql.jdbc.ResultSetImpl.close(ResultSetImpl.java:851) at com.alibaba.druid.pool.DruidPooledResultSet.close(DruidPooledResultSet.java:87) at com.alibaba.otter.canal.client.adapter.support.Util.sqlRS(Util.java:42) ... 15 common frames omitted Caused by: java.net.SocketException: Software caused connection abort: socket write error at java.net.SocketOutputStream.socketWrite0(Native Method) at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:111) at java.net.SocketOutputStream.write(SocketOutputStream.java:155) at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82) at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140) at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3725) ... 24 common frames omitted 2019-09-18 09:51:01.447 [Thread-26] ERROR c.a.o.canal.adapter.launcher.loader.CanalAdapterWorker - process error! com.alibaba.otter.canal.protocol.exception.CanalClientException: java.io.IOException: 你的主機中的軟件中止了一個已建立的連接。 at com.alibaba.otter.canal.client.impl.SimpleCanalConnector.ack(SimpleCanalConnector.java:351) at com.alibaba.otter.canal.adapter.launcher.loader.CanalAdapterWorker.process(CanalAdapterWorker.java:135) at java.lang.Thread.run(Thread.java:748) Caused by: java.io.IOException: 你的主機中的軟件中止了一個已建立的連接。 at sun.nio.ch.SocketDispatcher.write0(Native Method) at sun.nio.ch.SocketDispatcher.write(SocketDispatcher.java:51) at sun.nio.ch.IOUtil.writeFromNativeBuffer(IOUtil.java:93) at sun.nio.ch.IOUtil.write(IOUtil.java:65) at sun.nio.ch.SocketChannelImpl.write(SocketChannelImpl.java:471) at java.nio.channels.Channels.writeFullyImpl(Channels.java:78) at java.nio.channels.Channels.writeFully(Channels.java:98) at java.nio.channels.Channels.access$000(Channels.java:61) at java.nio.channels.Channels$1.write(Channels.java:174) at java.nio.channels.Channels$WritableByteChannelImpl.write(Channels.java:458) at com.alibaba.otter.canal.client.impl.SimpleCanalConnector.writeWithHeader(SimpleCanalConnector.java:393) at com.alibaba.otter.canal.client.impl.SimpleCanalConnector.writeWithHeader(SimpleCanalConnector.java:381) at com.alibaba.otter.canal.client.impl.SimpleCanalConnector.ack(SimpleCanalConnector.java:345) ... 2 common frames omitted 2019-09-18 09:51:01.449 [Thread-26] INFO c.a.o.canal.adapter.launcher.loader.CanalAdapterWorker - =============> Disconnect destination: example <============= 2019-09-18 09:51:02.450 [Thread-26] INFO c.a.o.canal.adapter.launcher.loader.CanalAdapterWorker - =============> Start to connect destination: example <============= 2019-09-18 09:51:02.454 [Thread-26] INFO c.a.o.canal.adapter.launcher.loader.CanalAdapterWorker - =============> Start to subscribe destination: example <============= 2019-09-18 09:51:02.455 [Thread-26] INFO c.a.o.canal.adapter.launcher.loader.CanalAdapterWorker - =============> Subscribe destination: example succeed <============= 2019-09-18 09:51:02.476 [pool-3-thread-1] INFO c.a.o.canal.client.adapter.logger.LoggerAdapterExample - DML: {"data":[{"id":5,"user_id":3,"name":"ttt","label":"lab-rst","c_time":1568727199000}],"database":"elppmdb","destination":"example","es":1568727199000,"groupId":null,"isDdl":false,"old":[{"label":"lab-rs","c_time":1568718604000}],"pkNames":["id"],"sql":"","table":"label","ts":1568771462474,"type":"UPDATE"}
錯誤信息一大堆，其實就是 其實關鍵字是 timeouts， 也就是 mysql 的連接 超時了！ 不用管， 重啟就好了！