Unanswered: Experiencing issues with 15.7 on linux, using more than 2 cpu sockets
I'm wondering if anyone out there is getting good performance using 15.7 on a linux server with lots of engines/cpu's. We are trying to upgrade a server that experiences an extremely high transaction rate during a set timeframe, with a large number of dynamic sql queries.
When we run the database on a two physical cpu box, it performs well with low cpubusy and low spinlock contention. However, when we run it on a 8 physical cpu server, performance takes a big hit. In both cases, we configure the same number of engines. We even tested the 8 processor box with 6 processors disabled, and performance improved.
The symptoms we see are high cpubusy during the high transaction times, and 19% or higher spinlock on sysusers and sysattributes. I understand that increasing engine count can increase contention. But it seems strange that I can run the same number of engines, but see a serious change in performance for the worse if I use more than 2 multicore processors. Everytime we have more than two sockets of multicore cpu's enabled(and probably distributing the engines across cores on numerous cpu's), we see high contention and cpubusy.
We have tried both threaded and processor mode. All caches are partitioned to the max.
Is anyone using 15.7 on linux in a high transaction environment, and using more than 2 multicore processors?