[
https://issues.apache.org/jira/browse/HBASE-23887?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17135251#comment-17135251
]
Danil Lipovoy commented on HBASE-23887:
---------------------------------------
And one more test. Before there are two different tables for scan and other for
gets. Now the table was the same:
!scan_and_gets2.png!
!image-2020-06-14-20-51-11-905.png!
The ratio looks different because reading the same blocks.
evicted (MB): 0, ratio 0.0, overhead (%): -100, heavy eviction counter: 0,
current caching DataBlock (%): 100
evicted (MB): 0, ratio 0.0, overhead (%): -100, heavy eviction counter: 0,
current caching DataBlock (%): 100
evicted (MB): 2170, ratio 1.09, overhead (%): 985, heavy eviction counter: 1,
current caching DataBlock (%): 91 < start
evicted (MB): 3763, ratio 1.08, overhead (%): 1781, heavy eviction counter: 2,
current caching DataBlock (%): 76
evicted (MB): 3306, ratio 1.07, overhead (%): 1553, heavy eviction counter: 3,
current caching DataBlock (%): 61
evicted (MB): 2508, ratio 1.06, overhead (%): 1154, heavy eviction counter: 4,
current caching DataBlock (%): 50
evicted (MB): 1824, ratio 1.04, overhead (%): 812, heavy eviction counter: 5,
current caching DataBlock (%): 42
evicted (MB): 1482, ratio 1.03, overhead (%): 641, heavy eviction counter: 6,
current caching DataBlock (%): 36
evicted (MB): 1140, ratio 1.01, overhead (%): 470, heavy eviction counter: 7,
current caching DataBlock (%): 32
evicted (MB): 913, ratio 1.0, overhead (%): 356, heavy eviction counter: 8,
current caching DataBlock (%): 29
evicted (MB): 912, ratio 0.89, overhead (%): 356, heavy eviction counter: 9,
current caching DataBlock (%): 26
evicted (MB): 684, ratio 0.76, overhead (%): 242, heavy eviction counter: 10,
current caching DataBlock (%): 24
evicted (MB): 684, ratio 0.61, overhead (%): 242, heavy eviction counter: 11,
current caching DataBlock (%): 22
evicted (MB): 456, ratio 0.51, overhead (%): 128, heavy eviction counter: 12,
current caching DataBlock (%): 21
evicted (MB): 456, ratio 0.42, overhead (%): 128, heavy eviction counter: 13,
current caching DataBlock (%): 20
evicted (MB): 456, ratio 0.33, overhead (%): 128, heavy eviction counter: 14,
current caching DataBlock (%): 19
evicted (MB): 342, ratio 0.33, overhead (%): 71, heavy eviction counter: 15,
current caching DataBlock (%): 19
evicted (MB): 342, ratio 0.32, overhead (%): 71, heavy eviction counter: 16,
current caching DataBlock (%): 19
evicted (MB): 342, ratio 0.31, overhead (%): 71, heavy eviction counter: 17,
current caching DataBlock (%): 19
evicted (MB): 228, ratio 0.3, overhead (%): 14, heavy eviction counter: 18,
current caching DataBlock (%): 19
evicted (MB): 228, ratio 0.29, overhead (%): 14, heavy eviction counter: 19,
current caching DataBlock (%): 19
evicted (MB): 228, ratio 0.27, overhead (%): 14, heavy eviction counter: 20,
current caching DataBlock (%): 19
evicted (MB): 228, ratio 0.25, overhead (%): 14, heavy eviction counter: 21,
current caching DataBlock (%): 19
evicted (MB): 228, ratio 0.24, overhead (%): 14, heavy eviction counter: 22,
current caching DataBlock (%): 19
evicted (MB): 228, ratio 0.22, overhead (%): 14, heavy eviction counter: 23,
current caching DataBlock (%): 19
evicted (MB): 228, ratio 0.21, overhead (%): 14, heavy eviction counter: 24,
current caching DataBlock (%): 19
evicted (MB): 228, ratio 0.2, overhead (%): 14, heavy eviction counter: 25,
current caching DataBlock (%): 19
evicted (MB): 228, ratio 0.17, overhead (%): 14, heavy eviction counter: 26,
current caching DataBlock (%): 19
evicted (MB): 456, ratio 0.17, overhead (%): 128, heavy eviction counter: 27,
current caching DataBlock (%): 18 < added gets (but table the same)
evicted (MB): 456, ratio 0.15, overhead (%): 128, heavy eviction counter: 28,
current caching DataBlock (%): 17
evicted (MB): 342, ratio 0.13, overhead (%): 71, heavy eviction counter: 29,
current caching DataBlock (%): 17
evicted (MB): 342, ratio 0.11, overhead (%): 71, heavy eviction counter: 30,
current caching DataBlock (%): 17
evicted (MB): 342, ratio 0.09, overhead (%): 71, heavy eviction counter: 31,
current caching DataBlock (%): 17
evicted (MB): 228, ratio 0.08, overhead (%): 14, heavy eviction counter: 32,
current caching DataBlock (%): 17
evicted (MB): 228, ratio 0.07, overhead (%): 14, heavy eviction counter: 33,
current caching DataBlock (%): 17
evicted (MB): 228, ratio 0.06, overhead (%): 14, heavy eviction counter: 34,
current caching DataBlock (%): 17
evicted (MB): 228, ratio 0.05, overhead (%): 14, heavy eviction counter: 35,
current caching DataBlock (%): 17
evicted (MB): 228, ratio 0.05, overhead (%): 14, heavy eviction counter: 36,
current caching DataBlock (%): 17
evicted (MB): 228, ratio 0.04, overhead (%): 14, heavy eviction counter: 37,
current caching DataBlock (%): 17
evicted (MB): 109, ratio 0.04, overhead (%): -46, heavy eviction counter: 37,
current caching DataBlock (%): 22 < back pressure
evicted (MB): 798, ratio 0.24, overhead (%): 299, heavy eviction counter: 38,
current caching DataBlock (%): 20
evicted (MB): 798, ratio 0.29, overhead (%): 299, heavy eviction counter: 39,
current caching DataBlock (%): 18
evicted (MB): 570, ratio 0.27, overhead (%): 185, heavy eviction counter: 40,
current caching DataBlock (%): 17
evicted (MB): 456, ratio 0.22, overhead (%): 128, heavy eviction counter: 41,
current caching DataBlock (%): 16
evicted (MB): 342, ratio 0.16, overhead (%): 71, heavy eviction counter: 42,
current caching DataBlock (%): 16
evicted (MB): 342, ratio 0.11, overhead (%): 71, heavy eviction counter: 43,
current caching DataBlock (%): 16
evicted (MB): 228, ratio 0.09, overhead (%): 14, heavy eviction counter: 44,
current caching DataBlock (%): 16
evicted (MB): 228, ratio 0.07, overhead (%): 14, heavy eviction counter: 45,
current caching DataBlock (%): 16
evicted (MB): 228, ratio 0.05, overhead (%): 14, heavy eviction counter: 46,
current caching DataBlock (%): 16
evicted (MB): 222, ratio 0.04, overhead (%): 11, heavy eviction counter: 47,
current caching DataBlock (%): 16
evicted (MB): 104, ratio 0.03, overhead (%): -48, heavy eviction counter: 47,
current caching DataBlock (%): 21 < interrupt gets
evicted (MB): 684, ratio 0.2, overhead (%): 242, heavy eviction counter: 48,
current caching DataBlock (%): 19
evicted (MB): 570, ratio 0.23, overhead (%): 185, heavy eviction counter: 49,
current caching DataBlock (%): 18
evicted (MB): 342, ratio 0.22, overhead (%): 71, heavy eviction counter: 50,
current caching DataBlock (%): 18
evicted (MB): 228, ratio 0.21, overhead (%): 14, heavy eviction counter: 51,
current caching DataBlock (%): 18
evicted (MB): 228, ratio 0.2, overhead (%): 14, heavy eviction counter: 52,
current caching DataBlock (%): 18
evicted (MB): 228, ratio 0.18, overhead (%): 14, heavy eviction counter: 53,
current caching DataBlock (%): 18
evicted (MB): 228, ratio 0.16, overhead (%): 14, heavy eviction counter: 54,
current caching DataBlock (%): 18
evicted (MB): 228, ratio 0.14, overhead (%): 14, heavy eviction counter: 55,
current caching DataBlock (%): 18
evicted (MB): 112, ratio 0.14, overhead (%): -44, heavy eviction counter: 55,
current caching DataBlock (%): 23 < back pressure
evicted (MB): 456, ratio 0.26, overhead (%): 128, heavy eviction counter: 56,
current caching DataBlock (%): 22
evicted (MB): 342, ratio 0.31, overhead (%): 71, heavy eviction counter: 57,
current caching DataBlock (%): 22
evicted (MB): 342, ratio 0.33, overhead (%): 71, heavy eviction counter: 58,
current caching DataBlock (%): 22
evicted (MB): 342, ratio 0.33, overhead (%): 71, heavy eviction counter: 59,
current caching DataBlock (%): 22
evicted (MB): 342, ratio 0.33, overhead (%): 71, heavy eviction counter: 60,
current caching DataBlock (%): 22
evicted (MB): 342, ratio 0.33, overhead (%): 71, heavy eviction counter: 61,
current caching DataBlock (%): 22
evicted (MB): 342, ratio 0.33, overhead (%): 71, heavy eviction counter: 62,
current caching DataBlock (%): 22
evicted (MB): 342, ratio 0.33, overhead (%): 71, heavy eviction counter: 63,
current caching DataBlock (%): 22
evicted (MB): 342, ratio 0.32, overhead (%): 71, heavy eviction counter: 64,
current caching DataBlock (%): 22
evicted (MB): 342, ratio 0.33, overhead (%): 71, heavy eviction counter: 65,
current caching DataBlock (%): 22
evicted (MB): 342, ratio 0.33, overhead (%): 71, heavy eviction counter: 66,
current caching DataBlock (%): 22
evicted (MB): 342, ratio 0.32, overhead (%): 71, heavy eviction counter: 67,
current caching DataBlock (%): 22
evicted (MB): 342, ratio 0.33, overhead (%): 71, heavy eviction counter: 68,
current caching DataBlock (%): 22
evicted (MB): 342, ratio 0.32, overhead (%): 71, heavy eviction counter: 69,
current caching DataBlock (%): 22
evicted (MB): 342, ratio 0.32, overhead (%): 71, heavy eviction counter: 70,
current caching DataBlock (%): 22
evicted (MB): 342, ratio 0.33, overhead (%): 71, heavy eviction counter: 71,
current caching DataBlock (%): 22
evicted (MB): 342, ratio 0.33, overhead (%): 71, heavy eviction counter: 72,
current caching DataBlock (%): 22
evicted (MB): 342, ratio 0.33, overhead (%): 71, heavy eviction counter: 73,
current caching DataBlock (%): 22
evicted (MB): 342, ratio 0.33, overhead (%): 71, heavy eviction counter: 74,
current caching DataBlock (%): 22
evicted (MB): 342, ratio 0.33, overhead (%): 71, heavy eviction counter: 75,
current caching DataBlock (%): 22
evicted (MB): 342, ratio 0.33, overhead (%): 71, heavy eviction counter: 76,
current caching DataBlock (%): 22
evicted (MB): 21, ratio 0.33, overhead (%): -90, heavy eviction counter: 76,
current caching DataBlock (%): 32
evicted (MB): 0, ratio 0.0, overhead (%): -100, heavy eviction counter: 0,
current caching DataBlock (%): 100
evicted (MB): 0, ratio 0.0, overhead (%): -100, heavy eviction counter: 0,
current caching DataBlock (%): 100
!ratio2.png!
> BlockCache performance improve by reduce eviction rate
> ------------------------------------------------------
>
> Key: HBASE-23887
> URL: https://issues.apache.org/jira/browse/HBASE-23887
> Project: HBase
> Issue Type: Improvement
> Components: BlockCache, Performance
> Reporter: Danil Lipovoy
> Assignee: Danil Lipovoy
> Priority: Minor
> Attachments: 1582787018434_rs_metrics.jpg,
> 1582801838065_rs_metrics_new.png, BC_LongRun.png,
> BlockCacheEvictionProcess.gif, cmp.png, evict_BC100_vs_BC23.png,
> eviction_100p.png, eviction_100p.png, eviction_100p.png, gc_100p.png,
> graph.png, image-2020-06-07-08-11-11-929.png,
> image-2020-06-07-08-19-00-922.png, image-2020-06-07-12-07-24-903.png,
> image-2020-06-07-12-07-30-307.png, image-2020-06-08-17-38-45-159.png,
> image-2020-06-08-17-38-52-579.png, image-2020-06-08-18-35-48-366.png,
> image-2020-06-14-20-51-11-905.png, ratio.png, ratio2.png,
> read_requests_100pBC_vs_23pBC.png, requests_100p.png, requests_100p.png,
> requests_new2_100p.png, requests_new_100p.png, scan.png, scan_and_gets.png,
> scan_and_gets2.png, wave.png
>
>
> Hi!
> I first time here, correct me please if something wrong.
> All latest information is here:
> [https://docs.google.com/document/d/1X8jVnK_3lp9ibpX6lnISf_He-6xrHZL0jQQ7hoTV0-g/edit?usp=sharing]
> 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.
> Sometimes we have more data than can fit into BlockCache and it is cause a
> high rate of evictions. In this case we can skip cache a block N and insted
> cache the N+1th block. Anyway we would evict N block quite soon and that why
> that skipping good for performance.
> ---
> Some information below isn't actual
> ---
>
>
> Example:
> Imagine we have little cache, just can fit only 1 block and we are trying to
> read 3 blocks with offsets:
> 124
> 198
> 223
> Current way - we put the block 124, then put 198, evict 124, put 223, evict
> 198. A lot of work (5 actions).
> With the feature - last few digits evenly distributed from 0 to 99. When we
> divide by modulus we got:
> 124 -> 24
> 198 -> 98
> 223 -> 23
> It helps to sort them. Some part, for example below 50 (if we set
> *hbase.lru.cache.data.block.percent* = 50) go into the cache. And skip
> others. It means we will not try to handle the block 198 and save CPU for
> other job. In the result - we put block 124, then put 223, evict 124 (3
> actions).
> 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 1-99, 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}
>
> Other parameters help to control when this logic will be enabled. It means it
> will work only while heavy reading going on.
> hbase.lru.cache.heavy.eviction.count.limit - set how many times have to run
> eviction process that start to avoid of putting data to BlockCache
> hbase.lru.cache.heavy.eviction.bytes.size.limit - set how many bytes have to
> evicted each time that start to avoid of putting data to BlockCache
> By default: if 10 times (100 secunds) evicted more than 10 MB (each time)
> then we start to skip 50% of data blocks.
> When heavy evitions process end then new logic off and will put into
> BlockCache all blocks again.
>
> Descriptions of the test:
> 4 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)
