materialized views fast refresh jobs are running from which instance of the the RAC

Hi,

We had several read-only materialized views on a database named MV_DB. These materialized views are fast refreshing from a database named MASTER_DB.

Both these databases were 10.2.0.4 single-instance databases.

We just convert these databases into 2 nodes RAC. So now we have MV_DB1, MV_DB2 and MASTER_DB1 , MASTER_DB2.

My quesiton is:

How can we know the materialized views are now fast refreshing from which instances MV_DB1 or MV_DB2.

In other words, which instance is firing the fast refresh jobs . I have tried to identify with :

select sid,job,instance from  dba_jobs_running.

But the column instance always returned 0.