troubshooting-sqoop 导出 TiDB表数据报com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

2019-11-22 17:15:27,705 FATAL [IPC Server handler 13 on 44844] org.apache.hadoop.mapred.TaskAttemptListenerImpl: Task: attempt_1574410493054_0011_m_000000_0 - exited : java.lang.RuntimeException: java.lang.RuntimeException: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.

at org.apache.sqoop.mapreduce.db.DBInputFormat.setDbConf(DBInputFormat.java:170)

at org.apache.sqoop.mapreduce.db.DBInputFormat.setConf(DBInputFormat.java:161)

at org.apache.hadoop.util.ReflectionUtils.setConf(ReflectionUtils.java:73)

at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:133)

at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:755)

at org.apache.hadoop.mapred.MapTask.run(MapTask.java:341)

at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:164)

at java.security.AccessController.doPrivileged(Native Method)

at javax.security.auth.Subject.doAs(Subject.java:422)

at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1920)

at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:158)

Caused by: java.lang.RuntimeException: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.

at org.apache.sqoop.mapreduce.db.DBInputFormat.getConnection(DBInputFormat.java:223)

at org.apache.sqoop.mapreduce.db.DBInputFormat.setDbConf(DBInputFormat.java:168)

... 10 more

Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

原因分析

1、TiDB数据库连接驱动包（当前是用的 mysql数据库连接驱动包）版本与 CDH集群的 sqoop组件版本不兼容。

2、CDH集群中的单一节点可以访问 TiDB数据库，其它节点与 TiDB数据库主机网络不通（假如 CDH集群有5个节点，需要5个节点都可以与 mysql的主机网络互通）。

此次报错原因是第二点。

解决办法

1、更新兼容当前 TiDB数据库连接驱动包（当前是用的 mysql数据库连接驱动包）与 CDH集群的 sqoop组件版本的驱动包。

2、关闭 CDH集群节点访问 TiDB数据库主机的防火墙，使得 CDH集群主机任何节点都可以访问 TiDB数据库。

异常日志

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.

at org.apache.sqoop.mapreduce.db.DBInputFormat.setDbConf(DBInputFormat.java:170)

at org.apache.sqoop.mapreduce.db.DBInputFormat.setConf(DBInputFormat.java:161)

at org.apache.hadoop.util.ReflectionUtils.setConf(ReflectionUtils.java:73)

at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:133)

at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:755)

at org.apache.hadoop.mapred.MapTask.run(MapTask.java:341)

at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:164)

at java.security.AccessController.doPrivileged(Native Method)

at javax.security.auth.Subject.doAs(Subject.java:422)

at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1920)

at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:158)

Caused by: java.lang.RuntimeException: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.

at org.apache.sqoop.mapreduce.db.DBInputFormat.getConnection(DBInputFormat.java:223)

at org.apache.sqoop.mapreduce.db.DBInputFormat.setDbConf(DBInputFormat.java:168)

... 10 more

Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.

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:411)

at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1116)

at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:348)

at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2391)

at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2428)

at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2213)

at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:797)

at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)

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:411)

at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:389)

at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:305)

at java.sql.DriverManager.getConnection(DriverManager.java:664)

at java.sql.DriverManager.getConnection(DriverManager.java:247)

at org.apache.sqoop.mapreduce.db.DBConfiguration.getConnection(DBConfiguration.java:302)

at org.apache.sqoop.mapreduce.db.DBInputFormat.getConnection(DBInputFormat.java:216)

... 11 more

Caused by: java.net.ConnectException: Connection timed out (Connection timed out)

at java.net.PlainSocketImpl.socketConnect(Native Method)

at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)

at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)

at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)

at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)

at java.net.Socket.connect(Socket.java:589)

at java.net.Socket.connect(Socket.java:538)

at java.net.Socket.<init>(Socket.java:434)

at java.net.Socket.<init>(Socket.java:244)

at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:257)

at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:298)

... 27 more