High number of queries to domain controllers

Hello,

We have a strange issue where we encountered millions of queries are going to the specific domain controllers. These queries to domain controllers came from only 1 isilon cluster, however we have many other isilon clusters which uses the same DC for authentication.

Note: Object level auditing is enabled AD end.

Of the 1 million queries(that were actually recorded), 998,875 were for event 4662 'An operation was performed on an object'.

The queries were split pretty evenly among 2-3 domain controllers

As per vendor EMC, Isilon should use tokens to store credentials once initially authenticated, it's not clear why repeat calls to domain controllers were being made.  We need to understand the cause of Cluster sending a high number of queries to domain controllers.

Please refer the events snap below and kindly help me to understand the cause and the fix.

Current OneFS: 8.0.0.4, however the issue was same when we were in OneFS 7.2.X

Thanks in advance

Regards,

guru