I can't comment to the exact meaning of the warning, but I can say the impact of reading from multiple threads with one session is a significant concern in itself given the current implementation of Oak. Under high throughput conditions the lock contention quickly becomes a significant performance bottleneck.
-Rob -----Original Message----- From: Alexander Klimetschek [mailto:[email protected]] Sent: Tuesday, April 08, 2014 6:20 PM To: [email protected] Subject: Session concurrency warning Hi, if I get this warning below, does "another thread is concurrently writing" mean that the other threads is using session WRITE methods? Or could it happen just because a session was shared between two threads, one only READing from the session, the other writing. *WARN* org.apache.jackrabbit.oak.jcr.delegate.SessionDelegate Attempt to perform Adding node [....] while another thread is concurrently writing to session-3831. Blocking until the other thread is finished using this session. Please review your code to avoid concurrent use of a session. java.lang.Exception: Stack trace of concurrent access to session-3831 at org.apache.jackrabbit.oak.jcr.delegate.SessionDelegate.perform(SessionDelegate.java:269) at org.apache.jackrabbit.oak.jcr.session.ItemImpl.perform(ItemImpl.java:113) at org.apache.jackrabbit.oak.jcr.session.NodeImpl.addNode(NodeImpl.java:253) Cheers, Alex
