[
https://issues.apache.org/jira/browse/HBASE-23887?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17043451#comment-17043451
]
Reid Chan commented on HBASE-23887:
-----------------------------------
Do you have BucketCache configured?
Your code will take effect only when:
1. have L1 only.
2. have L1 and use external L2.
But if have L1 and internal L2, it will lose its effect, since L1 serves META
only in this case, buf.getBlockType().isData() always return false.
And case 3 is a more general case in production environment....
We should cover case 3 as well, but in case 3, L2's memory are not managed by
JVM, so having no effect on GC.....
> BlockCache performance improve
> ------------------------------
>
> Key: HBASE-23887
> URL: https://issues.apache.org/jira/browse/HBASE-23887
> Project: HBase
> Issue Type: New Feature
> Reporter: Danil Lipovoy
> Priority: Minor
> Attachments: cmp.png
>
>
> Hi!
> I first time here, correct me please if something wrong.
> I want propose how to improve performance when data in HFiles much more than
> BlockChache (usual story in BigData). The idea - caching only part of DATA
> blocks. It is good becouse LruBlockCache starts to work and save huge amount
> of GC. See the picture in attachment with test below. Requests per second is
> higher, GC is lower.
>
> The key point of the code:
> Added the parameter: *hbase.lru.cache.data.block.percent* which by default =
> 100
>
> But if we set it 0-99, then will work the next logic:
>
>
> {code:java}
> public void cacheBlock(BlockCacheKey cacheKey, Cacheable buf, boolean
> inMemory) {
> if (cacheDataBlockPercent != 100 && buf.getBlockType().isData())
> if (cacheKey.getOffset() % 100 >= cacheDataBlockPercent)
> return;
> ...
> // the same code as usual
> }
> {code}
>
>
> Descriptions of the test:
> 3 nodes E5-2698 v4 @ 2.20GHz, 700 Gb Mem.
> 4 RegionServers
> 4 tables by 64 regions by 1.88 Gb data in each = 600 Gb total (only FAST_DIFF)
> Total BlockCache Size = 48 Gb (8 % of data in HFiles)
> Random read in 20 threads
>
> I am going to make Pull Request, hope it is right way to make some
> contribution in this cool product.
>
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
