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VictoriaMetrics/app/vmselect
Haley Wang 2b9e197cfb vmselect: use the last 20 raw samples to auto-calculate the lookbehind during range query
Previously, the first 20 raw samples were used for calculation.
But compare to the first 20 samples, the last 20 samples represent the latest state of the metrics,
so the lookbehind window calculated from them should be more accurate when applied to the most recent samples,
resulting in better query results for recent time ranges.

For example,if the scrape interval changes at day4, and the query range is set to last 7 days.
Applying the window derived from the first 20 samples(the old scrape interval) to new samples could result in consistently incorrect results from day4 through day11.
Conversely, applying the window derived from the last 20 samples (the new scrape interval) could lead to incorrect results for [day0-day4),
which are old states and generally less important.

This pull request does not address any specific bug, but change the general behavior, so there is no changelog.

Inspired by https://github.com/VictoriaMetrics/VictoriaMetrics/issues/10280, but not the fix for https://github.com/VictoriaMetrics/VictoriaMetrics/issues/10280.
2026-01-16 09:05:30 +02:00
..
2025-12-12 12:50:45 +01:00
2024-11-28 13:50:02 +01:00

vmselect performs the following tasks:

  • Splits incoming selects to tasks for vmstorage nodes and issues these tasks to all the vmstorage nodes in the cluster.

  • Merges responses from all the vmstorage nodes and returns a single response.

The vmui directory contains static contents built from app/vmui package with make vmui-update command. The vmui page is available at http://<vmselect>:8481/select/<accountID>/vmui/.