DB link call package within concurrent request.

Dear all,

I got one issue that I create a dblink to another system.

I also create 2 packages, 1 sysnoym. 1 package in EBS system. 1 package in other system.->use sysnonym link.

And I register one concurrent program to execute this package.

sometimes the concurrent job can complete normally. but sometimes will keep running till I terminate.

Our database is RAC environment. Is there anything I need to catch?

 thanks for your reply.