OSB : weblogic datasource suspended

This is the overall story: several JMS Proxy Services (MDB) use a certain DS (datasource). Each of these Proxy has 16 MDB created by OSB.
To avoid overloading the DB with too many concurrent requests we sized the Connection Pool (CP) of this DS to 25. Evidently if there is a burst of activity (JMS) on 2 different Proxy Services, the DS will be overloaded and eventually we shall get a

weblogic.jdbc.extensions.PoolDisabledSQLException: weblogic.common.resourcepool.ResourceDisabledException: Pool BLA is Suspended, cannot allocate resources to applications...

http://egherardini.wordpress.com/2011/04/27/oracle-soa-suite-11g-datasource-has-been-suspended/
select count(*) from v$process;
select count(*) from v$session;
select * from v$parameter where name in ('sessions','processes','transactions');


The only effective workaround I see is associating the same WorkManager with a Max Threads Constraint of 25 to ALL JMS Proxy Services.