Maybe it depends on the driver.
Did you measured whether open connections to Informix/DB2 from a simple Java program shows the same behaviour?
thanks from your reply
I did this test , but a simple java program with jdbc connection (10 connections) get all connections very soon.
i used same informix driver as jboss
Hmm, not sure what the issue can be. My first thought was a general slowness - but this can be excluded as the DB2 works.
Maybe you use a smaler minsize or don't prefill the pool, in this case the pool will be a lazy filled after start
Thanks again Wolf-Diieter
Problem solved by modifying onconfig properties of informix.
in informix (IDS 12) default value of threads that manage connection has decreased , by increasing related parameter problem solved.