hi folks, searched the forums and did not see this problem addressed. if it has a link would be appreciated.

i have a webapp instance, with multiple webapps being deployed and redeployed (it's a development environment). i have an application server-level (not web-app level) object ("manager") which has a reference to a singleton instance of a DAO object which is using hibernate. i was experiencing timeout problems with DBCP (well noted on these forums) and have switched to c3p0. each webapp is required to register/unregister with the manager (using a load-on-startup servlet's init/destroy methods). so,


initially (jvm startup), the manager instance is initialized in a static block. the register/unregister stuff happens fine, and as expected, when there are no webapps left shutdown gets called correctly. however, if i then redeploy without restarting the server, and try to get a new instance (which calls the Hibernate initialization code as follows:



) in registerClient(), i get the below error. note that this all works fine using DBCP, so i'm guessing i have to do something to accomodate c3p0...but i'm not sure what that might be. or is the answer to just always restart the server with a deploy (kind of a pain in development)? any ideas?

thanks in advance,
peter


Hibernate version:
hibernate 2.1,
c3p0 version 0.8.4.5


Mapping documents:

using resin, and programmatically creating a hibernate properties file to pass to configure with (jdbc connection params taken out):

<system-property hibernate.c3p0.acquire_increment="1"/>
<system-property hibernate.c3p0.idle_test_period="180"/>
<system-property hibernate.c3p0.max_size="100"/>
<system-property hibernate.c3p0.max_statements="0"/>
<system-property hibernate.c3p0.min_size="10"/>
<system-property hibernate.c3p0.timeout="100"/>

Full stack trace of any exception that occurs:
net.sf.hibernate.exception.GenericJDBCException: Cannot open connection
at net.sf.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:81)
at net.sf.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:70)
at net.sf.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:30)
at net.sf.hibernate.impl.BatcherImpl.convert(BatcherImpl.java:325)
at net.sf.hibernate.impl.BatcherImpl.openConnection(BatcherImpl.java:292)
at net.sf.hibernate.impl.SessionImpl.connect(SessionImpl.java:3361)
at net.sf.hibernate.impl.SessionImpl.connection(SessionImpl.java:3321)
at net.sf.hibernate.impl.BatcherImpl.prepareQueryStatement(BatcherImpl.java:66)
at net.sf.hibernate.loader.Loader.prepareQueryStatement(Loader.java:779)
at net.sf.hibernate.loader.Loader.doQuery(Loader.java:265)
at net.sf.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:133)
at net.sf.hibernate.loader.Loader.doList(Loader.java:1033)
at net.sf.hibernate.loader.Loader.list(Loader.java:1024)
at net.sf.hibernate.hql.QueryTranslator.list(QueryTranslator.java:854)
at net.sf.hibernate.impl.SessionImpl.find(SessionImpl.java:1553)
at net.sf.hibernate.impl.QueryImpl.list(QueryImpl.java:39)
at com.ch.qjOfferCache.DAO.hibernate.HibernateAppOfferDAO.doQuery(HibernateAppOfferDAO.java:461)
at com.ch.qjOfferCache.DAO.hibernate.HibernateAppOfferDAO.getAppDeptFromDeptClubCodes(HibernateAppOfferDAO.java:189)
at com.ch.qjOfferCache.offercache.OfferCacheManager.fetchJoinOffer(OfferCacheManager.java:459)
at com.ch.site.struts.actions.performers.ManageDBOfferCache.perform(ManageDBOfferCache.java:117)
at com.ch.site.struts.actions.LocaleAction.executePerformers(LocaleAction.java:134)
at com.ch.site.struts.actions.LocaleAction.perform(LocaleAction.java:92)
at org.apache.struts.action.Action.execute(Action.java:420)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:484)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:274)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
at com.ch.site.struts.CustomActionServlet.process(CustomActionServlet.java:29)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:525)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:165)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:103)
at com.caucho.server.http.FilterChainServlet.doFilter(FilterChainServlet.java:96)
at com.ch.site.filters.TrimLinesFilter.doFilter(TrimLinesFilter.java:48)
at com.caucho.server.http.FilterChainFilter.doFilter(FilterChainFilter.java:88)
at com.caucho.server.http.Invocation.service(Invocation.java:315)
at com.caucho.server.http.CacheInvocation.service(CacheInvocation.java:135)
at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:246)
at com.caucho.server.http.HttpRequest.handleConnection(HttpRequest.java:163)
at com.caucho.server.TcpConnection.run(TcpConnection.java:139)
at java.lang.Thread.run(Thread.java:534)
Caused by: java.sql.SQLException: com.mchange.v2.c3p0.PoolBackedDataSource@4adb34 [ connectionPoolDataSource -> com.mchange.v
2.c3p0.WrapperConnectionPoolDataSource@1ccbdf7 [ acquireIncrement -> 1, autoCommitOnClose -> false, connectionTesterClassName
-> com.mchange.v2.c3p0.impl.DefaultConnectionTester, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> fals
e, idleConnectionTestPeriod -> 180, initialPoolSize -> 10, maxIdleTime -> 100, maxPoolSize -> 100, maxStatements -> 0, minPoo
lSize -> 10, nestedDataSource -> com.mchange.v2.c3p0.DriverManagerDataSource@7d4275 [ description -> null, driverClass -> nul
l, factoryClassLocation -> null, jdbcUrl -> jdbc:informix-sqli://10.xxx.x.xx:9999/customer:INFORMIXSERVER=dbname, proper
ties -> {user=xxxxxx, password=xxxxxx} ] , propertyCycle -> 300, testConnectionOnCheckout -> false ] , factoryClassLocation -
> null, numHelperThreads -> 3 ] has been closed() -- you can no longer use it.
at com.mchange.v2.c3p0.PoolBackedDataSource.assertCpds(PoolBackedDataSource.java:129)
at com.mchange.v2.c3p0.PoolBackedDataSource.getPoolManager(PoolBackedDataSource.java:141)
at com.mchange.v2.c3p0.PoolBackedDataSource.getConnection(PoolBackedDataSource.java:58)
at net.sf.hibernate.connection.C3P0ConnectionProvider.getConnection(C3P0ConnectionProvider.java:33)
at net.sf.hibernate.impl.BatcherImpl.openConnection(BatcherImpl.java:289)
... 34 more

Name and version of the database you are using:
informix

ptptpt,

I'm not positive, but I have a guess about your problem, and if I'm right, your problem should go away if you upgrade to a recent c3p0-0.8.5-preX release. Can you give that a try, and drop a note if that resolves the problem?

If my guess is right, the issue is this: JNDI-based resources can be looked up withing a single JVM, or across JVM boundaries, via deserialization or derefencing. To deal with this, c3p0 adopts a one connection-pool-manager per DataSource per JVM policy. When c3p0 deserializes or unreferences a datasource, it looks up the appropriate connection-pool-manager and uses it, rather than blindly creating a new set of threads and pools. Prior to c3p0-0.8.5, this lookup was insufficiently precise, and two unrelated DataSources of identical configuration would find the same set of pools. If the connection-pool-manager had already been closed, well... it's a problem. Newer c3p0s retain a token representing the identity of the original DataSource, and only "finds" a connection-pool-manager if in fact the new DataSource was deserialized/dereferenced from the same original.

Note that even if your app has no truck with JNDI whatsoever, this problem can bite you, because prior to c3p0-0.8.5, two identically configured pooled DataSources shared the same resources, regardless of the fact that they were unrelated. c3p0-0.8.5 resolves this issue.

I hope this helps!

Steve (c3p0-maintainer)

steve,

thanks for the thoughtful reply. i did try c3p0-0.8.5-pre9.jar, but it did not seem to resolve the problem i was experiencing. since i really only needed to shutdown the connection pool when the jvm was shutdown, i wound up solving the problem by implementing a solution along the lines suggested here:

http://www.devx.com/getHelpOn/10MinuteSolution/20459

again thanks much for the suggestion and for c3p0!

cheers,
peter