Excessive PSOBJCACHE Updates After Upgrading to Tools 8.55

Hi All...

We are in the process of upgrading from Tools 8.53.15 to 8.55.06 (Campus Solutions 9). We've just started our performance testing and are finding that the system is suffering poor performance under moderate load - significantly worse than the same load prior to upgrading. Our testing uses load runner to simulate high student enrollment load. Normally we peak at 1500 concurrent users without any significant impact to user experience however after the upgrade we start to get transactions timing out at as little as 300 concurrent users.

What we've noticed is that the number of updates to PSOBJCACHE and PSOBJCACHELOCK has skyrocketed since the upgrade (more than 20 times increase in the number of updates/deletes to each record) and is causing row lock contention on the table which we believe the be the primary cause of the poor online response times. It appears to be constantly updating the cache for all of the users (OBJECTTYPENAME='UPM') however we're at a loss as to why it would be doing this.