From 22902521196eef5f38afa5474dc782551ceafd78 Mon Sep 17 00:00:00 2001 From: Zakhar Bessarab Date: Thu, 3 Aug 2023 19:04:19 +0400 Subject: [PATCH] docs: make phrase about dedup and evaluation interval relation less obscure (#4781) Value of `-dedup.minScrapeInterval` comand-line flag must be higher than `evaluation_interval` in order to make sure that only one sample on each evaluation will be left after deduplication. Moreover, value of `-dedup.minScrapeInterval` must be a multiple of vmalert's `evaluation_interval` in order to make sure that samples will be aligned between deduplication window periods. See: https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4774#issuecomment-1663940811 Signed-off-by: Zakhar Bessarab --- app/vmalert/README.md | 2 +- docs/vmalert.md | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/app/vmalert/README.md b/app/vmalert/README.md index 72077ebef5..f37fe962a0 100644 --- a/app/vmalert/README.md +++ b/app/vmalert/README.md @@ -519,7 +519,7 @@ Alertmanagers. To avoid recording rules results and alerts state duplication in VictoriaMetrics server don't forget to configure [deduplication](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#deduplication). -The recommended value for `-dedup.minScrapeInterval` must be greater or equal to vmalert `evaluation_interval`. +The recommended value for `-dedup.minScrapeInterval` must be multiple of vmalert's `evaluation_interval`. If you observe inconsistent or "jumping" values in series produced by vmalert, try disabling `-datasource.queryTimeAlignment` command line flag. Because of alignment, two or more vmalert HA pairs will produce results with the same timestamps. But due of backfilling (data delivered to the datasource with some delay) values of such results may differ, diff --git a/docs/vmalert.md b/docs/vmalert.md index d941caf0c4..cef7fb4ca6 100644 --- a/docs/vmalert.md +++ b/docs/vmalert.md @@ -530,7 +530,7 @@ Alertmanagers. To avoid recording rules results and alerts state duplication in VictoriaMetrics server don't forget to configure [deduplication](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#deduplication). -The recommended value for `-dedup.minScrapeInterval` must be greater or equal to vmalert `evaluation_interval`. +The recommended value for `-dedup.minScrapeInterval` must be multiple of vmalert's `evaluation_interval`. If you observe inconsistent or "jumping" values in series produced by vmalert, try disabling `-datasource.queryTimeAlignment` command line flag. Because of alignment, two or more vmalert HA pairs will produce results with the same timestamps. But due of backfilling (data delivered to the datasource with some delay) values of such results may differ,