OTTER中NODE日志告警：Communications link failure

2016-12-26 13:10:20.493 [DbLoadAction] WARN com.alibaba.otter.node.etl.load.loader.db.DbLoadAction - ##load phase one failed!
java.util.concurrent.ExecutionException: com.alibaba.otter.node.etl.load.exception.LoadException: org.springframework.transaction.Cann
otCreateTransactionException: Could not open JDBC Connection for transaction; nested exception is com.mysql.jdbc.exceptions.jdbc4.Comm
unicationsException: Communications link failure

The last packet successfully received from the server was 59,574 milliseconds ago. The last packet sent successfully to the server wa
s 0 milliseconds ago.
at org.springframework.jdbc.datasource.DataSourceTransactionManager.doBegin(DataSourceTransactionManager.java:240)
at org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(AbstractPlatformTransactionManage
r.java:371)
at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:127)
at com.alibaba.otter.node.etl.load.loader.db.DbLoadAction$DbLoadWorker.doCall(DbLoadAction.java:578)
at com.alibaba.otter.node.etl.load.loader.db.DbLoadAction$DbLoadWorker.call(DbLoadAction.java:541)
at com.alibaba.otter.node.etl.load.loader.db.DbLoadAction$DbLoadWorker.call(DbLoadAction.java:513)
at java.util.concurrent.FutureTask.run(FutureTask.java:262)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:744)
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet successfully received from the server was 59,574 milliseconds ago. The last packet sent successfully to the server wa
s 0 milliseconds ago.
at sun.reflect.GeneratedConstructorAccessor150.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:389)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1038)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3422)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3322)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3762)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2435)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2582)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2531)
at com.mysql.jdbc.ConnectionImpl.setAutoCommit(ConnectionImpl.java:4852)
at org.apache.commons.dbcp.DelegatingConnection.setAutoCommit(DelegatingConnection.java:371)
at org.apache.commons.dbcp.PoolingDataSource$PoolGuardConnectionWrapper.setAutoCommit(PoolingDataSource.java:328)
at org.springframework.jdbc.datasource.DataSourceTransactionManager.doBegin(DataSourceTransactionManager.java:223)
... 9 more
Caused by: java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexp
ectedly lost.
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:2914)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3332)
... 18 more

OTTER 中NODE 日志告警，可是同步是OK的，不 晓得这样的告警正常吗？

Start with com.alibaba.otter.node.etl.load.loader.db.DbLoadAction, especially DbLoadWorker.doCall at lines 513, 541, and 578, and trace the Spring transaction and MySQL connection failures shown in the report. Reproduce or inspect the warning while synchronization remains successful; done should establish whether this is expected and identify the appropriate handling.

Written by the indexing model from the issue text.