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Bug 1794616

Summary: Prometheus federation write is failing on a large scale cluster
Product: OpenShift Container Platform Reporter: Naga Ravi Chaitanya Elluri <nelluri>
Component: MonitoringAssignee: Sergiusz Urbaniak <surbania>
Status: CLOSED ERRATA QA Contact: Junqi Zhao <juzhao>
Severity: medium Docs Contact:
Priority: unspecified    
Version: 4.3.0CC: alegrand, anpicker, erooth, kakkoyun, lcosic, lseelye, mloibl, pkrupa, surbania
Target Milestone: ---   
Target Release: 4.4.0   
Hardware: Unspecified   
OS: Linux   
Whiteboard: aos-scalability-43
Fixed In Version: Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2020-05-04 11:26:35 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 1804574, 1805116    
Attachments:
Description Flags
Total time series in an 800 nodes cluster: 8301 none

Description Naga Ravi Chaitanya Elluri 2020-01-24 02:50:59 UTC 
Description of problem:
we observed bunch of errors related to "caller=federate.go:184 component=web msg="federation failed" err="write tcp 127.0.0.1:9090->127.0.0.1:36894: write: broken pipe"" ( full log attached ) on a large scale 4.3 cluster ( 800 nodes ) built using 4.3.0-rc.3 payload. Looking at the logs, increasing the scrape_timeout and scrape_interval might help avoid this at large node counts. We are not exactly sure why the federation is enabled by default.

Version-Release number of selected component (if applicable):
OpenShift build/payload version: 4.3.0-rc.3

How reproducible:
We haven't seen this error before as we didn't really scale the cluster to large number of nodes.

Steps to Reproduce:
1. Build a cluster using 4.3.0-rc.3 payload.
2. Scale the cluster to larger node counts.
3. Look at one of the prom replica logs.

Actual results:
caller=federate.go:184 component=web msg="federation failed" err="write tcp 127.0.0.1:9090->127.0.0.1:36894: write: broken pipe"

Expected results:
Metrics scraped within the scrape_timeout interval.

Additional info:
Full logs are at http://dell-r510-01.perf.lab.eng.rdu2.redhat.com/4.3/logs/prometheus_scrape/
Comment 1 Sergiusz Urbaniak 2020-01-27 14:41:46 UTC 
Created attachment 1655695 [details]
Total time series in an 800 nodes cluster: 8301
Comment 15 Junqi Zhao 2020-02-19 09:10:18 UTC 
Tested with 4.4.0-0.nightly-2020-02-17-211020,
the "up" metric is replaced by "count:up0" and "count:up1", "node_uname_info" is removed
Comment 17 errata-xmlrpc 2020-05-04 11:26:35 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, and where to find the updated
files, follow the link below.

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

https://access.redhat.com/errata/RHBA-2020:0581