Hi! I've been getting this error randomly:
<openjpa-2.1.0-r422266:1071316 fatal internal error> org.apache.openjpa.util.InternalException: Multiple concurrent threads attempted to access a single broker. By default brokers are not thread safe; if you require and/or intend a broker to be accessed by more than one thread, set the openjpa.Multithreaded property to true to override the default behavior. at org.apache.openjpa.kernel.BrokerImpl.endOperation(BrokerImpl.java:1935) ... The pattern in my web app is the "entity manager per request" pattern, implemented like this: http://www.uta.fi/~th77842/PersistenceRequestListener.java http://www.uta.fi/~th77842/PersistenceManager.java Basically, I force each request to have its own EntityManager. Some persisted entities are shared between threads, but not EntityManagers. The problem only occurs when it's a Tomcat specific thread (e.g. TP-Processor) using an EntityManager. I haven't had the problem using my own agent threads or using the ThreadPoolExecutor to process jobs. The problem has happened on inserts, selects or accessing a field in a persisted entity. The servlet container I use is Tomcat 6. The database is PostgreSQL 8.1.4. JPA related libraries I use: openjpa-2.1.0.jar, geronimo-jpa_2.0_spec-1.1.jar, geronimo-jta_1.1_spec-1.1.1.jar. Persistence configuration: <properties> <property name="openjpa.jdbc.DBDictionary" value="postgres"/> <property name="openjpa.jdbc.DriverDataSource" value="dbcp"/> <property name="openjpa.ConnectionProperties" value="DriverClassName=org.postgresql.Driver, Url=jdbc:postgresql://..., MaxActive=100, MaxWait=10000, Username=test, Password=test"/> <property name="openjpa.ConnectionDriverName" value="org.apache.commons.dbcp.BasicDataSource"/> <property name="openjpa.Log" value="log4j"/> <property name="openjpa.ConnectionFactoryProperties" value="PrettyPrint=true, PrettyPrintLineLength=80, PrintParameters=true"/> <property name="openjpa.DataCache" value="false"/> <property name="openjpa.InitializeEagerly" value="true"/> <property name="openjpa.jdbc.SynchronizeMappings" value="buildSchema"/> </properties> For the life of me I can't figure out why it's still happening. I am certain it's some subtle (or not so subtle) bug in my code or in the configuration I've done. I can understand if OpenJPA throws the error on persisted entities which are shared between threads, but it shouldn't happen on simple inserts. Any help would be appreciated. Thanks!
