Bug 1889711 - Prometheus metrics on disk take more space compared to OCP 4.5
Summary: Prometheus metrics on disk take more space compared to OCP 4.5
Alias: None
Product: OpenShift Container Platform
Classification: Red Hat
Component: Monitoring
Version: 4.6
Hardware: Unspecified
OS: Unspecified
Target Milestone: ---
: 4.6.z
Assignee: Simon Pasquier
QA Contact: Junqi Zhao
Depends On: 1889710
TreeView+ depends on / blocked
Reported: 2020-10-20 12:47 UTC by Simon Pasquier
Modified: 2020-11-30 16:45 UTC (History)
12 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
Clone Of: 1889710
Last Closed: 2020-11-30 16:45:31 UTC
Target Upstream Version:

Attachments (Terms of Use)

System ID Private Priority Status Summary Last Updated
Github openshift prometheus pull 62 0 None closed Bug 1889711: bump Prometheus to v2.22.2 2021-01-12 13:18:23 UTC
Red Hat Product Errata RHBA-2020:5115 0 None None None 2020-11-30 16:45:53 UTC

Description Simon Pasquier 2020-10-20 12:47:57 UTC
+++ This bug was initially created as a clone of Bug #1889710 +++

Description of problem:
Timers in Go >= 1.14 introduced a degradation with the compression of data on disk (see https://github.com/prometheus/prometheus/pull/7976 for details but users reported that block sizes increased up to 50% compared to previous versions). Prometheus for OCP 4.5 (and before) are built with Go 1.13 so the only affected version is OCP 4.6.

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
Run Prometheus at least 4 hours and measure the sample compression with:

rate(prometheus_tsdb_compaction_chunk_size_bytes_sum[8h]) / rate(prometheus_tsdb_compaction_chunk_samples_sum[8h])

Actual results:
More than 2 bytes on disk per sample.

Expected results:
Between 1 and 2 bytes on disk per sample.

Additional info:
See https://github.com/prometheus/prometheus/issues/7846

--- Additional comment from Simon Pasquier on 2020-10-20 12:45:35 UTC ---

Fixed in https://github.com/openshift/prometheus/pull/61 by bumping Prometheus to v2.22.0.

Comment 6 hongyan li 2020-11-23 03:24:10 UTC
already test with unmerged pr

Comment 9 errata-xmlrpc 2020-11-30 16:45:31 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (OpenShift Container Platform 4.6.6 bug fix update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.


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