Unfortunately, this is still occurring, nearly like clockwork every 8-12 hours. I've attached two images; one of the CPU usage for the last day and week, the other for the context-switch activity during the same period.
Every 8-12 hours, there is an (as yet) unexplained increase in CPU and context-switch activity that is unrelated to traffic patterns. I've haven't noticed any unusual GC times, but I will post a GC log next time this happens in case anybody sees something I'm missing.
From looking at the stack traces repeatedly, many of which are posted above, I haven't seen anything indicative; mostly threads just waiting.
We're currently running on Ubuntu, but are considering trying Solaris. Any thoughts on whether that could help, or would be better for performance anyway?
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