we have made some performance tests and we've observed that panelMenu rendering is responsible of 50% CPU usage overhead.
We've used a very simple application with search screens and result list in dataTable with datascroller.
There is allways a panelMenu on the left side with about 30 entries (6 panelGroups with 5 panelMenuItems each : generated html code for that is bigger than 60kb !!)
With Jmeter, we've injected 15 hits/s :
- access to search screen,
- search with criteria (*)
- paginate on next page with dataScroller
- ... and so on
(*) We know that retrieval data isn't significant and we can reproduce it without any database access.
We've noticed about 45% CPU usage on our big server (IBM p5-595 6-cpu !).
But for the same test without panelMenu, CPU is only 30% busy !
I think it's too expensive for a so simple object present in all screens of our applications. We can't use it in high throughput environment.
any suggestions are welcome