jiang hongyu [https://community.jboss.org/people/aquila_bj] created the discussion "Urgent problem: jboss as 5.1 offten happened time out exception" To view the discussion, visit: https://community.jboss.org/message/731223#731223 -------------------------------------------------------------- helllo every one, I have some urgent problem about JBOSS db pool with mysql database(5.1.41). I offen found my sql exception from jboss as server. Does anybody find the same error problem before, how to fix this problem. Can anybody help to find what's root cause about this? 2012-04-20 11:29:17,189 WARN  [org.jboss.resource.connectionmanager.JBossManagedConnectionPool] Unable to fill pool org.jboss.resource.JBossResourceException: Could not create connection; - nested throwable: (com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The last packet successfully received from the server was 6,128 milliseconds ago.  The last packet sent successfully to the server was 6,127 milliseconds ago.)         at org.jboss.resource.adapter.jdbc.xa.XAManagedConnectionFactory.getXAManagedConnection(XAManagedConnectionFactory.java:465)         at org.jboss.resource.adapter.jdbc.xa.XAManagedConnectionFactory.createManagedConnection(XAManagedConnectionFactory.java:409)         at org.jboss.resource.connectionmanager.InternalManagedConnectionPool.createConnectionEventListener(InternalManagedConnectionPool.java:633)         at org.jboss.resource.connectionmanager.InternalManagedConnectionPool.fillToMin(InternalManagedConnectionPool.java:541)         at org.jboss.resource.connectionmanager.PoolFiller.run(PoolFiller.java:74)         at java.lang.Thread.run(Thread.java:619) Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The last packet successfully received from the server was 6,128 milliseconds ago.  The last packet sent successfully to the server was 6,127 milliseconds ago.         at sun.reflect.GeneratedConstructorAccessor219.newInstance(Unknown Source)         at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)         at java.lang.reflect.Constructor.newInstance(Constructor.java:513)         at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)         at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1116)         at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3591)         at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3480)         at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4021)         at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:951)         at com.mysql.jdbc.MysqlIO.secureAuth411(MysqlIO.java:4602)         at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1328)         at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2389)         at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2422)         at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2207)         at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:797)         at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)         at sun.reflect.GeneratedConstructorAccessor125.newInstance(Unknown Source)         at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)         at java.lang.reflect.Constructor.newInstance(Constructor.java:513)         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 com.mysql.jdbc.jdbc2.optional.MysqlDataSource.getConnection(MysqlDataSource.java:440)         at com.mysql.jdbc.jdbc2.optional.MysqlDataSource.getConnection(MysqlDataSource.java:138)         at com.mysql.jdbc.jdbc2.optional.MysqlDataSource.getConnection(MysqlDataSource.java:108)         at com.mysql.jdbc.jdbc2.optional.MysqlXADataSource.getXAConnection(MysqlXADataSource.java:48)         at org.jboss.resource.adapter.jdbc.xa.XAManagedConnectionFactory.getXAManagedConnection(XAManagedConnectionFactory.java:449)         ... 5 more 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:3041)         at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3491)         ... 26 more -------------------------------------------------------------- Reply to this message by going to Community [https://community.jboss.org/message/731223#731223] Start a new discussion in Datasource Configuration at Community [https://community.jboss.org/choose-container!input.jspa?contentType=1&...]