I recently installed a DX3650 for a betting company. They are typically having ~4.500 concurrent (SSL) connections. I configured clusters with client IP transparency and SSL on the Listen Side. At 4.500 ccs the DX is at ~18-22% CPU load, which is a lot I think. If the connections go down to 1.000 in the morning hours the DX is at 8-10%. For me it seems a high CPU load for a small number of ccs. The memory is more or less constant at 38%.
So my question is till which watermark is CPU usage normal on a DX3650 / and 3680 as we soon going to replace the 3650? And at which level do I need to worry about?
There is no official number for "normal" CPU. Some things are memory intensive, others are CPU intensive. 4500 simultaneous connections is fairly low. On the 3650 only the SSL handshakes are done in hardware. You should take a look at the number of requests per second. Easy way is to clear cluster stats and "show server stats 1". One of the columns is Total Requests, you can see the difference between each entry. 22% CPU is very low. DX can run fine well into the 90's% with no issue. Performance for all users will be the same until CPU reaches 100%. The great thing about DX is ActiveN will allow you to scale linearly across N boxes if you need the capacity.
This is not an exhaustive list...
Uses Memory: Connection count SLB ActiveN FWLB
Uses CPU: Cluster transactions AppRules New SSL handshakes in xx00 boxes Bulk encryption in xx50 boxes New Proxy connections (cluster/forwarder)
DJ Skillman Manager, Technical Marketing DX Application Acceleration and Load Balancing