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Showing posts from October, 2014

Common list of Bottlenecks

Common list of Bottlenecks:
CPU: CPU overloadContext switches -> too many threads on a core, bad luck with the linux scheduler too many system calls, etc...IO waits -> all CPUs wait at the same speedCPU Caches: Caching data is a fine grained process, in order to find the right balance between having multiple instances with different values for data and heavy synchronization to keep the cached data consistent.Backplane throughput
Network: NIC maxed out, IRQ saturation, soft interrupts taking up 100% CPUDNS lookupsDropped packetsUnexpected routes with in the networkNetwork disk accessShared SANsServer failure -> no answer anymore from the serverMemory: Out of memory -> kills process, go into swap & grind to a haltOut of memory causing Disk Thrashing (related to swap)Memory library overheadMemory fragmentation In Java requires GC pausesIn C, malloc's start taking foreverDatabase:Working size exceeds available RAMLong &…