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Ted Yu commented on HBASE-7404: ------------------------------- @Chunhui: This is an important feature. Please fill out Release Notes so that users know how to use it. > Bucket Cache:A solution about CMS,Heap Fragment and Big Cache on HBASE > ---------------------------------------------------------------------- > > Key: HBASE-7404 > URL: https://issues.apache.org/jira/browse/HBASE-7404 > Project: HBase > Issue Type: New Feature > Affects Versions: 0.94.3 > Reporter: chunhui shen > Assignee: chunhui shen > Fix For: 0.96.0, 0.94.5 > > Attachments: 7404-trunk-v10.patch, 7404-trunk-v11.patch, > 7404-trunk-v12.patch, 7404-trunk-v13.patch, 7404-trunk-v13.txt, > 7404-trunk-v14.patch, BucketCache.pdf, hbase-7404-94v2.patch, > hbase-7404-trunkv2.patch, hbase-7404-trunkv9.patch, Introduction of Bucket > Cache.pdf > > > First, thanks @neil from Fusion-IO share the source code. > What's Bucket Cache? > It could greatly decrease CMS and heap fragment by GC > It support a large cache space for High Read Performance by using high speed > disk like Fusion-io > 1.An implementation of block cache like LruBlockCache > 2.Self manage blocks' storage position through Bucket Allocator > 3.The cached blocks could be stored in the memory or file system > 4.Bucket Cache could be used as a mainly block cache(see CombinedBlockCache), > combined with LruBlockCache to decrease CMS and fragment by GC. > 5.BucketCache also could be used as a secondary cache(e.g. using Fusionio to > store block) to enlarge cache space > How about SlabCache? > We have studied and test SlabCache first, but the result is bad, because: > 1.SlabCache use SingleSizeCache, its use ratio of memory is low because kinds > of block size, especially using DataBlockEncoding > 2.SlabCache is uesd in DoubleBlockCache, block is cached both in SlabCache > and LruBlockCache, put the block to LruBlockCache again if hit in SlabCache , > it causes CMS and heap fragment don't get any better > 3.Direct heap performance is not good as heap, and maybe cause OOM, so we > recommend using "heap" engine > See more in the attachment and in the patch -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira