otter能正常同步，但是过一会channel就会挂起，日志报错表已经存在

web管理界面上能看到如下日志信息：

日志异常信息一：

pid:1 nid:1 exception:setl:com.alibaba.otter.node.etl.load.exception.LoadException: java.util.concurrent.ExecutionException: com.alibaba.otter.node.etl.load.exception.LoadException: com.alibaba.otter.node.etl.load.exception.LoadException: org.springframework.jdbc.BadSqlGrammarException: StatementCallback; bad SQL grammar []; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'student' already exists Caused by: java.util.concurrent.ExecutionException: com.alibaba.otter.node.etl.load.exception.LoadException: com.alibaba.otter.node.etl.load.exception.LoadException: org.springframework.jdbc.BadSqlGrammarException: StatementCallback; bad SQL grammar []; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'student' already exists at java.util.concurrent.FutureTask.report(FutureTask.java:122) at java.util.concurrent.FutureTask.get(FutureTask.java:192) at com.alibaba.otter.node.etl.load.loader.db.DataBatchLoader.load(DataBatchLoader.java:107) at com.alibaba.otter.node.etl.load.loader.OtterLoaderFactory.load(OtterLoaderFactory.java:50) at com.alibaba.otter.node.etl.load.LoadTask$1.run(LoadTask.java:85) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) Caused by: com.alibaba.otter.node.etl.load.exception.LoadException: com.alibaba.otter.node.etl.load.exception.LoadException: org.springframework.jdbc.BadSqlGrammarException: StatementCallback; bad SQL grammar []; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'student' already exists Caused by: com.alibaba.otter.node.etl.load.exception.LoadException: org.springframework.jdbc.BadSqlGrammarException: StatementCallback; bad SQL grammar []; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'student' already exists Caused by: org.springframework.jdbc.BadSqlGrammarException: StatementCallback; bad SQL grammar []; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'student' already exists at org.springframework.jdbc.support.SQLStateSQLExceptionTranslator.doTranslate(SQLStateSQLExceptionTranslator.java:98) at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:72) at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:80) at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:407) at com.alibaba.otter.node.etl.load.loader.db.DbLoadAction.doDdl(DbLoadAction.java:357) at com.alibaba.otter.node.etl.load.loader.db.DbLoadAction.load(DbLoadAction.java:135) at com.alibaba.otter.node.etl.load.loader.db.DbLoadAction$$FastClassByCGLIB$$d932a4cb.invoke() at net.sf.cglib.proxy.MethodProxy.invoke(MethodProxy.java:191) at org.springframework.aop.framework.Cglib2AopProxy$DynamicAdvisedInterceptor.intercept(Cglib2AopProxy.java:618) at com.alibaba.otter.node.etl.load.loader.db.DbLoadAction$$EnhancerByCGLIB$$80fd23c2.load() at com.alibaba.otter.node.etl.load.loader.db.DataBatchLoader$2.call(DataBatchLoader.java:198) at com.alibaba.otter.node.etl.load.loader.db.DataBatchLoader$2.call(DataBatchLoader.java:189) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'student' already exists 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:389) at com.mysql.jdbc.Util.getInstance(Util.java:372) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:980) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3835) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3771) 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.execSQL(ConnectionImpl.java:2489) at com.mysql.jdbc.StatementImpl.execute(StatementImpl.java:848) at com.mysql.jdbc.StatementImpl.execute(StatementImpl.java:742) at org.apache.commons.dbcp.DelegatingStatement.execute(DelegatingStatement.java:264) at org.apache.commons.dbcp.DelegatingStatement.execute(DelegatingStatement.java:264) at com.alibaba.otter.node.etl.load.loader.db.DbLoadAction$1.doInStatement(DbLoadAction.java:365) at com.alibaba.otter.node.etl.load.loader.db.DbLoadAction$1.doInStatement(DbLoadAction.java:357) at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:396) ... 14 more

日志异常信息二：

pid:-1 nid:null exception:cid:1 restart recovery successful for rid:-1

是什么导致channel会自动挂起？这两个异常是怎么造成的？麻烦看下，谢谢~

原提问者GitHub用户 KaimingWan