And apply hbase-2180 to your cluster. St.Ack
On Mon, Feb 15, 2010 at 4:16 PM, Dan Washusen <d...@reactive.org> wrote: > Maybe the block cache is thrashing? > > If you are regularly writing data to your tables then it's possible that the > block cache is no longer being effective. On the region server web UI check > the blockCacheHitRatio value. You want this value to be high (0 - 100). If > this value is low it means that HBase has to go to disk to fetch blocks of > data. You can control the amount of VM memory that HBase allocates to the > block cache using the "hfile.block.cache.size" property (default is 0.2 > (20%)). > > Cheers, > Dan > > On 16 February 2010 10:45, James Baldassari <ja...@dataxu.com> wrote: > >> Hi, >> >> Does anyone have any tips to share regarding optimization for random >> read performance? For writes I've found that setting a large write >> buffer and setting auto-flush to false on the client side significantly >> improved put performance. Are there any similar easy tweaks to improve >> random read performance? >> >> I'm using HBase 0.20.3 in a very read-heavy real-time system with 1 >> master and 3 region servers. It was working ok for a while, but today >> there was a severe degradation in read performance. Restarting Hadoop >> and HBase didn't help, are there are no errors in the logs. Read >> performance starts off around 1,000-2,000 gets/second but quickly >> (within minutes) drops to around 100 gets/second. >> >> I've already looked at the performance tuning wiki page. On the server >> side I've increased hbase.regionserver.handler.count from 10 to 100, but >> it didn't help. Maybe this is expected because I'm only using a single >> client to do reads. I'm working on implementing a client pool now, but >> I'm wondering if there are any other settings on the server or client >> side that might improve things. >> >> Thanks, >> James >> >> >> >
