On Mon, Feb 28, 2011 at 10:22 AM, benchmark <zsl...@gmail.com> wrote: > Here is the vmstat 1 results. Is that a lot of context switches? this is a > box with 8 cpus and hyperthreading enabled on centOS.
Is this output with 250 threads running? When you say "8 cpus", do you mean 1 physical CPU with 4 cores with HyperThreading enabled? What's the model number of that CPU? You're seeing only ~1000 context switches per second per core, that's not completely unreasonable. Your server seems more idle than anything else... I'd suggest looking at a packet capture to see what the network latency looks like, I'm guessing you'll see that the slow responses you're seeing are indeed really slow and that the problem comes from the server-side. What's your HBase cluster like? How many nodes, what hardware, what configuration? What's you block cache hit ratio? -- Benoit "tsuna" Sigoure Software Engineer @ www.StumbleUpon.com
