For your query tests, are they all from a single thread? Have you tried reading from multiple threads/processes in parallel - that sounds more like your use case.
-chris On Apr 25, 2011, at 10:04 PM, Weihua JIANG <[email protected]> wrote: > The query is all random read. The scenario is that a user want to > query his own monthly bill report, e.g. to query what happened on his > bill in March, or Feb, etc. Since every user may want to do so, we > can't predict who will be the next to ask for such monthly bill > report. > > 2011/4/26 Stack <[email protected]>: >>> Currently, to store bill records, we can achieve about 30K record/second. >>> >> >> Can you use bulk load? See http://hbase.apache.org/bulk-loads.html >> >>> However, the query performance is quite poor. We can only achieve >>> about 600~700 month_report/second. That is, each region server can >>> only serve query for about 100 row/second. Block cache hit ratio is >>> about 20%. >>> >> >> This is random accesses? Why random accesses and not scans? >> >> >>> Do you have any advice on how to improve the query performance? >>> >> >> See above cited performance section from website book. >> >> >>> Below is some metrics info reported by region server: >>> 2011-04-26T10:56:12 hbase.regionserver: >>> RegionServer=regionserver50820, blockCacheCount=40969, >>> blockCacheEvictedCount=216359, blockCacheFree=671152504, >>> blockCacheHitCachingRatio=20, blockCacheHitCount=67936, >>> blockCacheHitRatio=20, blockCacheMissCount=257675, >>> blockCacheSize=2743351688, compactionQueueSize=0, >>> compactionSize_avg_time=0, compactionSize_num_ops=7, >>> compactionTime_avg_time=0, compactionTime_num_ops=7, flushQueueSize=0, >>> flushSize_avg_time=0, flushSize_num_ops=0, flushTime_avg_time=0, >>> flushTime_num_ops=0, fsReadLatency_avg_time=46, >>> fsReadLatency_num_ops=257905, fsSyncLatency_avg_time=0, >>> fsSyncLatency_num_ops=1726, fsWriteLatency_avg_time=0, >>> fsWriteLatency_num_ops=0, memstoreSizeMB=0, regions=169, >>> requests=82.1, storefileIndexSizeMB=188, storefiles=343, stores=169 >>> 2011-04-26T10:56:22 hbase.regionserver: >>> RegionServer=regionserver50820, blockCacheCount=42500, >>> blockCacheEvictedCount=216359, blockCacheFree=569659040, >>> blockCacheHitCachingRatio=20, blockCacheHitCount=68418, >>> blockCacheHitRatio=20, blockCacheMissCount=259206, >>> blockCacheSize=2844845152, compactionQueueSize=0, >>> compactionSize_avg_time=0, compactionSize_num_ops=7, >>> compactionTime_avg_time=0, compactionTime_num_ops=7, flushQueueSize=0, >>> flushSize_avg_time=0, flushSize_num_ops=0, flushTime_avg_time=0, >>> flushTime_num_ops=0, fsReadLatency_avg_time=44, >>> fsReadLatency_num_ops=259547, fsSyncLatency_avg_time=0, >>> fsSyncLatency_num_ops=1736, fsWriteLatency_avg_time=0, >>> fsWriteLatency_num_ops=0, memstoreSizeMB=0, regions=169, >>> requests=92.2, storefileIndexSizeMB=188, storefiles=343, stores=169 >>> 2011-04-26T10:56:32 hbase.regionserver: >>> RegionServer=regionserver50820, blockCacheCount=39238, >>> blockCacheEvictedCount=221509, blockCacheFree=785944072, >>> blockCacheHitCachingRatio=20, blockCacheHitCount=69043, >>> blockCacheHitRatio=20, blockCacheMissCount=261095, >>> blockCacheSize=2628560120, compactionQueueSize=0, >>> compactionSize_avg_time=0, compactionSize_num_ops=7, >>> compactionTime_avg_time=0, compactionTime_num_ops=7, flushQueueSize=0, >>> flushSize_avg_time=0, flushSize_num_ops=0, flushTime_avg_time=0, >>> flushTime_num_ops=0, fsReadLatency_avg_time=39, >>> fsReadLatency_num_ops=261070, fsSyncLatency_avg_time=0, >>> fsSyncLatency_num_ops=1746, fsWriteLatency_avg_time=0, >>> fsWriteLatency_num_ops=0, memstoreSizeMB=0, regions=169, >>> requests=128.77777, storefileIndexSizeMB=188, storefiles=343, >>> stores=169 >>> >> >> This is hard to read but I don't see anything obnoxious. >> >> >>> >>> And we also tried to disable block cache, it seems the performance is >>> even a little bit better. And it we use the configuration 6 DN servers >>> + 3 RS servers, we can get better throughput at about 1000 >>> month_report/second. I am confused. Can any one explain the reason? >>> >> >> Sounds like you are doing all random reads? Do you have to? >> >> St.Ack >>
