On Tue, Apr 19, 2011 at 4:46 PM, Dmitriy Lyubimov <[email protected]> wrote: > Right now i am shooting scans returning between 3 and 40 rows and > regardless of data size, approximately 500-400 QPS. The data tables > are almost empty and in-memory, so they surely should fit in those 40% > heap dedicated to them. >
LRU in the regionserver logs its hit rate. You might check it. > As soon as i go to our 10-node cluster, the response times drop to > 25ms per scan, regardless of # of records. I set scan block cache size > to 100 (rows?), otherwise i was getting outrages numbers reaching as > far out as 300-400ms. > Otherwise you are doing an rpc per fetch. > It's my understanding the timing should be actually still much closer > to my local tests than to 25ms. > Yes. I would think so. > So... how do i attack this ? increase regionserver handler count? What > the latency should i be able to reach for extremely small data records > (<=200bytes)? > 40 rows of < 200 bytes each coming out of cache should be fast... around the times you are seeing for local. St.Ack
