Grails' save(flush:true) hangs thread in socketRead0

Question

There is a transactional=true service in Grails 2.2 where I do just the following:

...
client.save(flush: true) // it hangs here
...

If I remove flush:true, the execution passes further although it hangs calling a withTransaction later.

I have never met such a problem with my current large project before.

I have an idea to throw out some flush'es and withTransaction's but that's kinda unwanted because there are a bunch of them in the code currently. So it would be a painful change even if it will fix the problem.

Any idea how to cure / investigate that?

Grails 2.2 / Java 1.6 / Windows 7 x64 / Oracle XE

Hanged thread's stack trace:

java.net.SocketInputStream.socketRead0(Native Method)
java.net.SocketInputStream.read(SocketInputStream.java:150)
java.net.SocketInputStream.read(SocketInputStream.java:121)
oracle.net.ns.Packet.receive(Unknown Source)
oracle.net.ns.DataPacket.receive(Unknown Source)
oracle.net.ns.NetInputStream.getNextPacket(Unknown Source)
oracle.net.ns.NetInputStream.read(Unknown Source)
oracle.net.ns.NetInputStream.read(Unknown Source)
oracle.net.ns.NetInputStream.read(Unknown Source)
oracle.jdbc.driver.T4CMAREngine.unmarshalUB1(T4CMAREngine.java:971)
oracle.jdbc.driver.T4CMAREngine.unmarshalSB1(T4CMAREngine.java:941)
oracle.jdbc.driver.T4C8Oall.receive(T4C8Oall.java:432)
oracle.jdbc.driver.T4CPreparedStatement.doOall8(T4CPreparedStatement.java:181)
oracle.jdbc.driver.T4CPreparedStatement.execute_for_rows(T4CPreparedStatement.java:543)
oracle.jdbc.driver.OraclePreparedStatement.executeBatch(OraclePreparedStatement.java:8674)
   - locked oracle.jdbc.driver.T4CPreparedStatement@36df36e5
   - locked oracle.jdbc.driver.T4CConnection@788d1087
org.apache.commons.dbcp.DelegatingStatement.executeBatch(DelegatingStatement.java:297)
org.apache.commons.dbcp.DelegatingStatement.executeBatch(DelegatingStatement.java:297)
org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:70)
org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:268)
org.hibernate.jdbc.AbstractBatcher.prepareStatement(AbstractBatcher.java:114)
org.hibernate.jdbc.AbstractBatcher.prepareStatement(AbstractBatcher.java:109)
org.hibernate.jdbc.AbstractBatcher.prepareBatchStatement(AbstractBatcher.java:244)
org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2412)
org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2875)
org.hibernate.action.EntityInsertAction.execute(EntityInsertAction.java:79)
org.hibernate.engine.ActionQueue.execute(ActionQueue.java:273)
org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:265)
org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:184)
org.codehaus.groovy.grails.orm.hibernate.events.PatchedDefaultFlushEventListener.performExecutions(PatchedDefaultFlushEventListener.java:46)
org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51)
org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1216)
org.codehaus.groovy.grails.orm.hibernate.metaclass.SavePersistentMethod.flushSession(SavePersistentMethod.java:87)
org.codehaus.groovy.grails.orm.hibernate.metaclass.SavePersistentMethod$1.doInHibernate(SavePersistentMethod.java:60)
org.springframework.orm.hibernate3.HibernateTemplate.doExecute(HibernateTemplate.java:406)
org.springframework.orm.hibernate3.HibernateTemplate.execute(HibernateTemplate.java:339)
org.codehaus.groovy.grails.orm.hibernate.metaclass.SavePersistentMethod.performSave(SavePersistentMethod.java:56)
org.codehaus.groovy.grails.orm.hibernate.metaclass.AbstractSavePersistentMethod.doInvokeInternal(AbstractSavePersistentMethod.java:215)
org.codehaus.groovy.grails.orm.hibernate.metaclass.AbstractDynamicPersistentMethod.invoke(AbstractDynamicPersistentMethod.java:63)
sun.reflect.GeneratedMethodAccessor662.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:601)
org.springsource.loaded.ri.ReflectiveInterceptor.jlrMethodInvoke(ReflectiveInterceptor.java:1243)
org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite$PojoCachedMethodSite.invoke(PojoMetaMethodSite.java:189)
org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite.call(PojoMetaMethodSite.java:53)
org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:45)
org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite.call(PojoMetaMethodSite.java:55)
org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:124)
org.codehaus.groovy.grails.orm.hibernate.HibernateGormInstanceApi.save(HibernateGormEnhancer.groovy:911)
xxx.domain.Consumer.save(Consumer.groovy)
xxx.domain.Consumer$save.call(Unknown Source)
org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:45)
org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:108)
org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:116)
xxx.UserService.createUser(UserService.groovy:350)
............

Answer 1

Your stacktrace points at the likely problem:

oracle.jdbc.driver.OraclePreparedStatement.executeBatch(OraclePreparedStatement.java:8674)
   - locked oracle.jdbc.driver.T4CPreparedStatement@36df36e5
   - locked oracle.jdbc.driver.T4CConnection@788d1087

You have a stuck thread (or threads) on your database and the app is hanging waiting for the threads. You need to check your database status to see if you can determine which queries are hanging. It's all possible updating to the latest JDBC driver will help.

The reason this is happening when you use flush: true is because it's forcing your Hibernate session to flush to the database, where it encounters the stuck thread.