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Posted to user@hbase.apache.org by Ted Tuttle <te...@mentacapital.com> on 2012/11/16 19:31:11 UTC
increasing block cache size
Hello All-
We are running 5 node v0.94 cluster on machines w/ 32G of RAM. I'd like
to utilize more of our memory for block cache. So I have a couple of
questions.
Currently, we are running RSs w/ 16G heap and the following memory
settings:
hfile.block.cache.size=0.25
hbase.regionserver.global.memstore.upperLimit=0.2
hbase.regionserver.global.memstore.lowerLimit=0.15
Typically overall stats for RS are:
numberOfOnlineRegions=228, usedHeapMB=7870, maxHeapMB=16358
Used heap typically goes to ~10G then we get GC back down to about 6-8G.
So by my reckoning we have about 25% of heap unutilized.
More detailed, typical RS info:
numberOfOnlineRegions=245, numberOfStores=245, numberOfStorefiles=249,
storefileIndexSizeMB=17, rootIndexSizeKB=17688,
totalStaticIndexSizeKB=11910, totalStaticBloomSizeKB=36107,
memstoreSizeMB=361, readRequestsCount=-1829306476,
writeRequestsCount=16153099, compactionQueueSize=0, flushQueueSize=0,
usedHeapMB=11407, maxHeapMB=16358, blockCacheSizeMB=3201.95,
blockCacheFreeMB=887.66, blockCacheCount=3243,
blockCacheHitCount=2932634895, blockCacheMissCount=5223350,
blockCacheEvictedCount=678037, blockCacheHitRatio=99%,
blockCacheHitCachingRatio=99%, hdfsBlocksLocalityIndex=95
>From these stats I see my memstores are always <1G or <6% of heap.
So here are my questions:
1) Are memstore settings above relevant in v0.94 w/ off heap memstores
the default?
2) We have good locality and cache hits. I'd like to take block cache
size to 50% and increase overall heap to 24G. Any concerns about this
given stats above?
3) Any other memory recommendations?
Thanks,
Ted