at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
at java.lang.Thread.run(Thread.java:534)
Caused by: com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception:
** BEGIN NESTED EXCEPTION **
java.net.SocketException
MESSAGE: Broken pipe
STACKTRACE:
java.net.SocketException: Broken pipe
at java.net.SocketOutputStream.socketWrite0(Native Method)
at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:92)
at java.net.SocketOutputStream.write(SocketOutputStream.java:136)
at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:66)
at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:124)
... 40 more
配置：mysql4.0.1alpha，是虚拟主机上面的mysql，具体配置不明
jdbc：mysql-connector-java-3.1.10
连接池配置：
hibernate.c3p0.timeout=1000
hibernate.c3p0.max_statements=100
hibernate.c3p0.idle_test_period=300
hibernate.c3p0.acquire_increment=5
hibernate.c3p0.validate=false
网上找到http://swforum.sun.com/jive/thread.jspa?threadID=51022&messageID=186798
其中一段：
原文：
Well, one of the key things that should be apparent to mysql users, but may not be,
be sure wait_timeout in your my.cnf file is set to a value greater than the idle_timeout set in your connection pool. (they both are seconds in units)
otherwise the server will kill the connection from behind, with the pool thinking it should still be alive, you'll get one of these here SocketException fangles.
意思是：mysql配置中的wait_timeout值一定要大于等于连接池种的idel_timeout值。否则mysql会在wait_timeout的时间后关闭连接，然而连接池还认为该连接可用，这样就会产生SocketException。
根据这种说法我把连接池的timeout值有1000改成50(暂定认为mysql中的wait_timeout值是50),看能否解决问题。
转
