Commit graph

4 commits

Author SHA1 Message Date
Aliaksandr Valialkin
c38a10e143
app/vmselect/netstorage: eliminate memory allocation for sortBlocksHeap arg when calling mergeSortBlocks() 2023-01-09 21:08:51 -08:00
Aliaksandr Valialkin
1f9d605988
app/vmselect/netstorage: consistently select the sample with the biggest value out of samples with identical timestamps
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3333

This fix is based on https://github.com/VictoriaMetrics/VictoriaMetrics/pull/3620 ,
but doesn't slow down the common case with merging replicated data blocks so significantly.

Benchmark results:

Before the change:

BenchmarkMergeSortBlocks/replicationFactor-1-4         	   13968	     85643 ns/op	 956.53 MB/s	    1700 B/op	       1 allocs/op
BenchmarkMergeSortBlocks/replicationFactor-2-4         	   10806	    109171 ns/op	1500.77 MB/s	    2191 B/op	       1 allocs/op
BenchmarkMergeSortBlocks/replicationFactor-3-4         	    8887	    130623 ns/op	1881.45 MB/s	    2660 B/op	       1 allocs/op
BenchmarkMergeSortBlocks/replicationFactor-4-4         	    7440	    157348 ns/op	2082.52 MB/s	    3174 B/op	       1 allocs/op
BenchmarkMergeSortBlocks/replicationFactor-5-4         	    6534	    184473 ns/op	2220.38 MB/s	    3612 B/op	       1 allocs/op
BenchmarkMergeSortBlocks/overlapped-blocks-bestcase-4  	   13419	     85205 ns/op	 961.44 MB/s	    2213 B/op	       1 allocs/op
BenchmarkMergeSortBlocks/overlapped-blocks-worstcase-4 	     579	   1894900 ns/op	  43.23 MB/s	   46760 B/op	       1 allocs/op

After the change:

BenchmarkMergeSortBlocks/replicationFactor-1-4         	   13832	     85298 ns/op	 960.40 MB/s	    1716 B/op	       1 allocs/op
BenchmarkMergeSortBlocks/replicationFactor-2-4         	    8833	    134222 ns/op	1220.66 MB/s	    2675 B/op	       1 allocs/op
BenchmarkMergeSortBlocks/replicationFactor-3-4         	    6487	    184830 ns/op	1329.65 MB/s	    3636 B/op	       1 allocs/op
BenchmarkMergeSortBlocks/replicationFactor-4-4         	    4977	    236318 ns/op	1386.61 MB/s	    4733 B/op	       1 allocs/op
BenchmarkMergeSortBlocks/replicationFactor-5-4         	    4088	    296734 ns/op	1380.36 MB/s	    5761 B/op	       1 allocs/op
BenchmarkMergeSortBlocks/overlapped-blocks-bestcase-4  	   14083	     84067 ns/op	 974.47 MB/s	    2110 B/op	       1 allocs/op
BenchmarkMergeSortBlocks/overlapped-blocks-worstcase-4 	     536	   2043534 ns/op	  40.09 MB/s	   50511 B/op	       1 allocs/op
2023-01-09 13:01:48 -08:00
Roman Khavronenko
7c0ae3a86a
lib/storage: keep sample with the biggest value on timestamp conflict (#3421)
The change leaves raw sample with the biggest value for identical
timestamps per each `-dedup.minScrapeInterval` discrete interval
when the deduplication is enabled.

```
benchstat old.txt new.txt
name                                         old time/op    new time/op    delta
DeduplicateSamples/minScrapeInterval=1s-10      817ns ± 2%     832ns ± 3%      ~     (p=0.052 n=10+10)
DeduplicateSamples/minScrapeInterval=2s-10     1.56µs ± 1%    2.12µs ± 0%   +35.19%  (p=0.000 n=9+7)
DeduplicateSamples/minScrapeInterval=5s-10     1.32µs ± 3%    1.65µs ± 2%   +25.57%  (p=0.000 n=10+10)
DeduplicateSamples/minScrapeInterval=10s-10    1.13µs ± 2%    1.50µs ± 1%   +32.85%  (p=0.000 n=10+10)

name                                         old speed      new speed      delta
DeduplicateSamples/minScrapeInterval=1s-10   10.0GB/s ± 2%   9.9GB/s ± 3%      ~     (p=0.052 n=10+10)
DeduplicateSamples/minScrapeInterval=2s-10   5.24GB/s ± 1%  3.87GB/s ± 0%   -26.03%  (p=0.000 n=9+7)
DeduplicateSamples/minScrapeInterval=5s-10   6.22GB/s ± 3%  4.96GB/s ± 2%   -20.37%  (p=0.000 n=10+10)
DeduplicateSamples/minScrapeInterval=10s-10  7.28GB/s ± 2%  5.48GB/s ± 1%   -24.74%  (p=0.000 n=10+10)
```

https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3333
Signed-off-by: hagen1778 <roman@victoriametrics.com>

Signed-off-by: hagen1778 <roman@victoriametrics.com>
2022-12-08 18:06:11 -08:00
Aliaksandr Valialkin
743ff84863
app/vmselect/netstorage: optimize mergeSortBlocks function
- Use binary search instead of linear scan when locating the run of smallest timestamps
  in blocks with intersected time ranges. This should improve performance
  when merging blocks with big number of samples

- Skip samples with duplicate timestamps. This should increase query performance
  in cluster version of VictoriaMetrics with the enabled replication.
2022-07-09 00:34:42 +03:00