Today, my Nuxeo has creshed two times.

Firstly:

2013-12-06 09:49:01,160 ERROR [org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/nuxeo].[Nuxeo WebEngine Servlet]] Servlet.service() for servlet [Nuxeo WebEngine Servlet] in context with path [/nuxeo] threw exception [java.lang.IllegalStateException: Cannot create a session after the response has been committed] with root cause
2013-12-06 09:54:40,655 DEBUG [org.nuxeo.ecm.platform.thumbnail.converter.AnyToThumbnailConverter] mimetype: application/vnd.ms-excel
2013-12-06 09:54:40,658 DEBUG [org.nuxeo.ecm.platform.thumbnail.converter.AnyToThumbnailConverter] converterName: anyToPdfToThumbnail

Secondly:

2013-12-06 15:52:38,910 INFO  [org.artofsolving.jodconverter.office.OfficeConnection] disconnected: 'socket,host=127.0.0.1,port=2003,tcpNoDelay=1'
2013-12-06 15:52:38,935 WARN  [org.artofsolving.jodconverter.office.PooledOfficeManager] connection lost unexpectedly; attempting restart
2013-12-06 15:52:38,940 INFO  [org.artofsolving.jodconverter.office.ManagedOfficeProcess] process exited with code 137
2013-12-06 15:52:39,091 DEBUG [org.nuxeo.ecm.platform.thumbnail.converter.AnyToThumbnailConverter] mimetype: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
2013-12-06 15:52:39,092 DEBUG [org.nuxeo.ecm.platform.thumbnail.converter.AnyToThumbnailConverter] converterName: anyToPdfToThumbnail
2013-12-06 15:52:39,251 INFO  [org.artofsolving.jodconverter.office.OfficeProcess] starting process with acceptString 'socket,host=127.0.0.1,port=2003,tcpNoDelay=1' and profileDir '/data2/nuxeo/tmp/.jodconverter_socket_host-127.0.0.1_port-2003_56'
2013-12-06 15:52:42,270 WARN  [org.artofsolving.jodconverter.office.OfficeProcess] Restarting OOo after code 81 ...
2013-12-06 15:52:43,302 INFO  [org.artofsolving.jodconverter.office.OfficeProcess] started process : pid = 24081
2013-12-06 15:52:43,461 INFO  [org.artofsolving.jodconverter.office.OfficeConnection] connected: 'socket,host=127.0.0.1,port=2003,tcpNoDelay=1'
2013-12-06 15:53:18,064 ERROR [org.nuxeo.runtime.transaction.TransactionHelper] Unable to commit/rollback  org.nuxeo.runtime.jtajca.NuxeoContainer$UserTransactionImpl@159171e5
javax.transaction.RollbackException: Unable to commit: Transaction timeout
at org.apache.geronimo.transaction.manager.TransactionImpl.commit(TransactionImpl.java:267)
at org.apache.geronimo.transaction.manager.TransactionManagerImpl.commit(TransactionManagerImpl.java:252)
at org.nuxeo.runtime.jtajca.NuxeoContainer$TransactionManagerWrapper.commit(NuxeoContainer.java:745)
at org.nuxeo.runtime.jtajca.NuxeoContainer$UserTransactionImpl.commit(NuxeoContainer.java:621)
at org.nuxeo.runtime.transaction.TransactionHelper.commitOrRollbackTransaction(TransactionHelper.java:289)
at org.nuxeo.ecm.core.work.WorkHolder.run(WorkHolder.java:84)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:724)

In both cases, the tomcat was removed from memory without information in other logs. It was enough to start it without any other activities.

Nuxeo: 5.8 HF02
Java(TM) SE Runtime Environment (build 1.7.0_25-b15)
Java HotSpot(TM) 64-Bit Server VM (build 23.25-b01, mixed mode)
Red Hat Enterprise Linux Server release 6.2 (Santiago) kernel 2.6.32-220.7.1.el6.x86_64