1 Reply Latest reply on Dec 21, 2007 12:00 PM by Sohil Shah

    Changing the isolation level for Portal's TreeCache

    Ed Kusnitz Newbie

      Environment: JBoss AS 4.0.5GA
      Configuration: All
      Portal version: 2.4.1
      Using jboss-portal-ha.sar in a cluster

      We are noticing that there are quite a bit of locking problems with the JBoss Portal TreeCache. Here is one example:

      read lock for /org/hibernate/cache/StandardQueryCache/sql: select userinstan0_.PK as PK16_, userinstan0_.INSTANCE_PK as INSTANCE2_16_, userinstan0_.SER_STATE as SER3_16_, userinstan0_.USER_ID as USER4_16_, userinstan0_.PORTLET_REF as PORTLET5_16_ from JBP_INSTANCE_PER_USER userinstan0_ where userinstan0_.INSTANCE_PK=? and userinstan0_.USER_ID=?; parameters: ; named parameters: {userId=jplaprise@ascentmedia.com, instanceKey=25} could not be acquired by GlobalTransaction:<ensumapp01-01:32792>:903 after 10000 ms. Locks: Read lock owners: []
      
      Write lock owner: GlobalTransaction:<ensumapp01-01:32792>:902
      
      , lock info: write owner=GlobalTransaction:<ensumapp01-01:32792>:902 (activeReaders=0, activeWriter=Thread[TP-Processor1,5,jboss], waitingReaders=0, waitingWriters=0, waitingUpgrader=0)


      We are hardly using Portal features at all and in fact plan to remove it in the next version of our application. We are not using Portal state replication or ClusteredSingleSignOn.

      My question is, we have noticed that by default Portal uses REPEATABLE_READ for the isolation level for its TreeCache. What are the implications of downgrading it to READ_COMMITTED or even lower? Would this possibly eliminate the problem?



        • 1. Re: Changing the isolation level for Portal's TreeCache
          Sohil Shah Master

          I am not sure if READ_COMMITTED will solve your issue fully.

          I would lean towards using optmistic locking instead.

          Unfortunately, optimistic locking support does not exist in 2.4. It has been fixed in 2.6 in addition to other locking issues in a clustered setup.

          We are still striving to make it even better.

          If possible, try upgrading to our latest portal release which is 2.6.3

          Thanks