Commit Graph

19 Commits

Author SHA1 Message Date
Artem Navoiev
e1005209ba
docs: mention staleNaN handling during deduplication
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5587

Signed-off-by: hagen1778 <roman@victoriametrics.com>
2024-01-16 20:11:45 +02:00
Oleksandr Redko
0e1c395609
app,lib: fix typos in comments () 2023-02-13 09:32:35 -08:00
Aliaksandr Valialkin
e56d5e1918
lib/storage: follow-up after 7c0ae3a86a
- Update docs at https://docs.victoriametrics.com/#deduplication
- Optimize the deduplication loop a bit

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3333
2022-12-08 18:18:49 -08:00
Roman Khavronenko
909cd04c55
lib/storage: keep sample with the biggest value on timestamp conflict ()
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 18:18:36 -08:00
Aliaksandr Valialkin
361b08c30e
lib/storage: leave the last sample per each discrete interval during the deduplicaton
This aligns better with staleness logic in Prometheus - https://prometheus.io/docs/prometheus/latest/querying/basics/#staleness
2022-05-02 21:59:31 +03:00
Aliaksandr Valialkin
d36fdbe537
lib/storage: deduplicate samples more thoroughly
Previously some duplicate samples may be left on disk for time series with high churn rate.
This may result in higher disk space usage.
2021-12-15 16:00:30 +02:00
Aliaksandr Valialkin
bc3923111b
lib/storage: return dedup interval in milliseconds from GetDedupInterval()
This removes duplicate .Milliseconds() calls after GetDedupInterval() calls.
2021-12-15 13:27:27 +02:00
Aliaksandr Valialkin
cdfe854c9b
lib/storage: explicitly pass dedupInterval to DeduplicateSamples() and deduplicateSamplesDuringMerge()
This improves the code readability and debuggability, since the output of these functions
stops depending on global state.
2021-12-14 20:52:29 +02:00
Aliaksandr Valialkin
ef3c58d7a3 lib/storage: properly determine when the deduplication is needed in needsDedup
Previously needsDedup() could return true if the de-duplication wasn't needed for the following case:

         d < interval
           /     \
   |        v | v        |
     interval   interval

Now it properly returns false for this case
2021-07-12 10:54:51 +03:00
Aliaksandr Valialkin
b16e19c053 lib/storage/dedup.go: go fmt 2020-04-26 14:37:36 +03:00
Aliaksandr Valialkin
a0000c3a6e lib/storage: improve deduplication algorithm
Now it leaves only the first data point on each `-dedup.minScrapeInterval` interval.

Previously it may leave two data points on the interval. This could lead to unexpected results
for `histogram_quantile(phi, sum(rate(buckets)) by (le))` query.
2020-04-26 13:10:18 +03:00
Aliaksandr Valialkin
8ed0d5471a lib/storage: correctly handle -dedup.minScrapeInterval values smaller than 8ms
Such small values may be used for removing samples with duplicate timestamps.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/409 for details.
2020-04-10 16:40:41 +03:00
Aliaksandr Valialkin
4c56acbafa lib/storage: remove duplicate data points on 7/8*minScrapeInterval interval instead of 1/2*minScrapeInterval
This should reduce storage usage and should improve deduplication accuracy
2020-04-01 15:47:04 +03:00
Aliaksandr Valialkin
cf9aee4ec3 all: properly split vm_deduplicated_samples_total among cluster components
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/345
2020-02-27 23:47:51 +02:00
Aliaksandr Valialkin
110cce24d9 lib/storage: add vm_ prefix to deduplicated_samples_total metric 2020-02-21 19:33:36 +02:00
Aliaksandr Valialkin
ea66212c93 lib/storage: move -dedup.minScrapeInterval flag outside lib/storage, so it doesnt show up in vminsert in cluster version 2020-02-10 13:07:25 +02:00
Aliaksandr Valialkin
56d6b8ed0a lib/storage: do not deduplicate blocks with less than 32 samples during merge
This should improve deduplication accuracy for blocks with higher number of samples.
2020-02-04 18:41:37 +02:00
Aliaksandr Valialkin
7cde594696 all: do not clash flag description with back-quoted flag types
See https://golang.org/pkg/flag/#PrintDefaults for more details.
2020-02-04 15:56:01 +02:00
Aliaksandr Valialkin
e3adc095bd all: add -dedup.minScrapeInterval command-line flag for data de-duplication
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/86
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/278
2020-01-31 01:18:54 +02:00