ibatis + glassfish: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure [duplicate]

This question already has answers here: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure (51 answers) Closed 6 years ago.

I keep getting the error randomly:

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

Anyone got ideas?

ERROR: java.sql.Connection - Error calling Connection.setAutoCommit:
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet successfully received from the server was 129,064 milliseconds ago.  The last packet sent successfully to the server was 0 milliseconds ago.
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Dele开发者_如何学CgatingConstructorAccessorImpl.java:27)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:409)
    at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1118)
    at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3055)
    at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2941)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3489)

Caused by: java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.
    at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:2502)
    at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2952)
    ... 83 more

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The MySQL server does not listen on the TCP port 3306 by default. To allow (remote) TCP connections, comment the following line in /etc/mysql/my.cnf:

skip-networking