1 Reply Latest reply on May 30, 2011 7:09 AM by Wolf-Dieter Fink

    Database behind DefaultDS in JBoss 5.1

    Willem Noorduin Newbie

      Normally, JBoss comes with something known as HypersonicDB, which is coupled to DefaultDS and needed for transactioncontrol, JMS and stuff like that. I have managed to change this into a MySQL database (because this is more supported and more visible for administration). When I start two profiles in one cluster, let them use the same database, I see:


      wnoordui@nlptc27b09:/apps/jboss/configs$ mysql -u root -p jboss

      Welcome to the MySQL monitor.  Commands end with ; or \g.

      Your MySQL connection id is 17

      Server version: 5.0.77-log Source distribution


      Type 'help;' or '\h' for help. Type '\c' to clear the buffer.


      mysql> show tables;






      1 row in set (0.47 sec)


      mysql> select * from HILOSEQUENCES;














      1 row in set (0.19 sec)




      I am what puzzeled and have the following questions:


      • What information is written to this database during runtime.?

      • Do you have to make one database / cluster or one database / JBoss-AS node ?

      • Are there known performance issues when I move the database to another server ?




        • 1. Re: Database behind DefaultDS in JBoss 5.1
          Wolf-Dieter Fink Master

          JBossMessaging will store the messages to the db, to separate the different cluster members there is the ServerPeerId (you must set for each instance).


          You might have different DB instances for each JBoss instance, but that will not be a cluster (as I understand).

          The persistent data is not shared, e.g. JMS failover. You also do not want to have different application data DB right!?


          Normally we install the DB on a different system as the JBoss instances.

          The drawback is the network traffic and latency, but it is less. Also you separate the JBoss instances (e.g. blade systems )