We have several ESX 3.5 clusters but are experiencing performance issues with one cluster in particular.
Memory consumption http://molcat.bl.uk/gwicks/esxmemory20100216.png
Why does the cluster memory dip by 50% every hour at 10 minutes and 25 minutes past the hour. We think this may be ESX doing some kind of memory reclaiming, but we think it's also causing the application to slow down, something we observed during our load testing.
There are 8 guests, 4CPU and 16GB Redhat 5 servers with Java apps (Lucene text search)