Broken Pipe in Hibernate application

Question

I have an application in Tomcat 8 Engine which have both: JDBC and Hibernate connections to two different databases. The Hibernate connection fails after 3-4 hours of user inactivity also I have c3p0 properties in hibernate.cfg.xml

hibernate.c3p0.min_size 1

hibernate.c3p0.idle_test_period 100

the exception stacktrace:

STACKTRACE:

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:109)
at java.net.SocketOutputStream.write(SocketOutputStream.java:153)
at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140)
at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:2637)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1554)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1665)
at com.mysql.jdbc.Connection.execSQL(Connection.java:3176)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1153)
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1266)
at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeQuery(NewProxyPreparedStatement.java:116)
at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.extract(ResultSetReturnImpl.java:80)
at org.hibernate.loader.Loader.getResultSet(Loader.java:2065)
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1862)
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1838)
at org.hibernate.loader.Loader.doQuery(Loader.java:909)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:354)
at org.hibernate.loader.Loader.doList(Loader.java:2551)
at org.hibernate.loader.Loader.doList(Loader.java:2537)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2367)
at org.hibernate.loader.Loader.list(Loader.java:2362)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:496)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:387)
at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:229)
at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1260)
at org.hibernate.internal.QueryImpl.list(QueryImpl.java:103)
at DAO.CarsDAOimpl.getData(CarsDAOimpl.java:121)

does anybody has an idea what is going on and how to fix that? UPD: here is about memory state: Runtime runtime = Runtime.getRuntime(); long freeMemory = runtime.freeMemory(); ... free memory: 183787192

Answer 1

Yes, I have had the same problem. Try to add a validationQuery to your DataSource.

Here is how I have defined mine:

<Resource auth="Container"
          type="javax.sql.DataSource"
          name="jdbc/mydb"
          driverClassName="com.mysql.jdbc.Driver"
          url="jdbc:mysql://localhost/mydb"
          maxActive="10"
          maxIdle="5"
          validationQuery="SELECT 1"
          testOnBorrow="true"
          testWhileIdle="true"
          timeBetweenEvictionRunsMillis="10000"
          minEvictableIdleTimeMillis="60000"
          username="..." password="..."/>