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Incidents/2022-09-08 codfw api-https api appserver appserver parsoid degradation: Difference between revisions

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imported>Clément Goubert
(Additional timeline information)
 
imported>Clément Goubert
 
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{{irdoc|status=draft}}
#REDIRECT [[Incidents/2022-09-08 codfw appservers degradation]]
 
==Summary==
{{Incident scorecard
| task = T317340
| paged-num = 1
| responders-num = 3
| coordinators = claime
| start = 2022-09-08 15:18:18
| end = 2022-09-08 15:51:18
| metrics = Response time and 5xx rate
| impact = For 2 minutes, api-https, api_appserver and appserver in codfw were in a degraded state
For 16 minutes, parsoid in codfw was in a degraded state
}}
 
An nginx server restart (RC) triggered an etcdmirror outage during a wikimedia-config deployment. When etcdmirror was restarted, a wrong state was synchronized which depooled a part of api-https api appserver appserver and parsoid servers.
 
{{TOC|align=right}}
 
==Timeline==
<mark>Write a step by step outline of what happened to cause the incident, and how it was remedied.  Include the lead-up to the incident, and any epilogue.</mark>
 
<mark>Consider including a graphs of the error rate or other surrogate.</mark>
 
<mark>Link to a specific offset in SAL using the SAL tool at https://sal.toolforge.org/ ([https://sal.toolforge.org/production?q=synchronized&d=2012-01-01 example])</mark>
 
''All times in UTC.''
 
https://grafana.wikimedia.org/d/RIA1lzDZk/application-servers-red?orgId=1&var-site=codfw&var-cluster=api_appserver&var-method=GET&var-code=200&var-php_version=All&from=1662651131187&to=1662651531187
https://grafana.wikimedia.org/d/RIA1lzDZk/application-servers-red?orgId=1&var-site=codfw&var-cluster=appserver&var-method=GET&var-code=200&var-php_version=All&from=1662651131187&to=1662651531187
https://grafana.wikimedia.org/d/RIA1lzDZk/application-servers-red?orgId=1&var-site=codfw&var-cluster=parsoid&var-method=GET&var-code=200&var-php_version=All&from=1662651131187&to=1662651531187
 
*??? : moritzm updates nginx, causing a restart
*15:17:24 : conf2005 systemd[1]: etcdmirror-conftool-eqiad-wmnet.service crashes
*15:18:18 : claime launches scap sync-file and notices errors
*15:22:02: irc alert | PROBLEM - etcdmirror-conftool-eqiad-wmnet service on conf2005 is CRITICAL: CRITICAL - Expecting active but unit etcdmirror-conftool-eqiad-wmnet is failed
*15:28:36 : jayme notices issues with conf2005/etcdmirror
*15:33:29 : akosiaris restarts etcdmirror
*15:34:00~: User-visible degradation begins
*15:34:42 : _joe_  notices https://config-master.wikimedia.org/pybal/codfw/api-https
*15:35:36 : _joe_ repools api-https
*15:36:32 : _joe_ repools api_appserver
*15:36:42 : _joe_ repools appserver
*15:36:42~: User-visible degradation ends
*15:50:32 : claime repools parsoid
 
==Detection==
<mark>Write how the issue was first detected.  Was automated monitoring first to detect it? Or a human reporting an error?</mark>
 
claime reports errors during scap sync-file
 
<mark>Copy the relevant alerts that fired in this section.</mark>
 
15:22:02  +icinga-wm | PROBLEM - etcdmirror-conftool-eqiad-wmnet service on conf2005 is CRITICAL: CRITICAL - Expecting active but unit etcdmirror-conftool-eqiad-wmnet is failed
 
<mark>Did the appropriate alert(s) fire? Was the alert volume manageable? Did they point to the problem with as much accuracy as possible?</mark>
 
Alert fired but (no page)?
 
<mark>TODO: If human only, an actionable should probably be to "add alerting".</mark>
 
==Conclusions==
 
<mark>OPTIONAL: General conclusions (bullet points or narrative)</mark>
 
===What went well?===
 
*…
 
<mark>OPTIONAL: (Use bullet points) for example: automated monitoring detected the incident, outage was root-caused quickly, etc</mark>
 
===What went poorly?===
 
*…
 
<mark>OPTIONAL: (Use bullet points) for example: documentation on the affected service was unhelpful, communication difficulties, etc</mark>
 
===Where did we get lucky?===
 
*…
 
<mark>OPTIONAL: (Use bullet points) for example: user's error report was exceptionally detailed, incident occurred when the most people were online to assist, etc</mark>
 
==Links to relevant documentation==
 
*…
 
<mark>Add links to information that someone responding to this alert should have (runbook, plus supporting docs). If that documentation does not exist, add an action item to create it.</mark>
 
==Actionables==
 
*…
 
<mark>Create a list of action items that will help prevent this from happening again as much as possible. Link to or create a Phabricator task for every step.</mark>
 
<mark>Add the [[phab:project/view/4758/|#Sustainability (Incident Followup)]] and the [[phab:project/profile/4626/|#SRE-OnFIRE (Pending Review & Scorecard)]]  Phabricator tag to these tasks.</mark>
 
==Scorecard==
 
 
{| class="wikitable"
|+[[Incident Scorecard|Incident Engagement  ScoreCard]]
!
!Question
!Answer
(yes/no)
!Notes
|-
! rowspan="5" |People
|Were the people responding to this incident sufficiently different than the previous five incidents?
|
|
|-
|Were the people who responded prepared enough to respond effectively
|
|
|-
|Were fewer than five people paged?
|
|
|-
|Were pages routed to the correct sub-team(s)?
|
|
|-
|Were pages routed to online (business hours) engineers?  ''Answer “no” if engineers were paged after business hours.''
|
|
|-
! rowspan="5" |Process
|Was the incident status section actively updated during the incident?
|
|
|-
|Was the public status page updated?
|
|
|-
|Is there a phabricator task for the incident?
|
|
|-
|Are the documented action items assigned?
|
|
|-
|Is this incident sufficiently different from earlier incidents so as not to be a repeat occurrence?
|
|
|-
! rowspan="5" |Tooling
|To the best of your knowledge was the open task queue free of any tasks that would have prevented this incident? ''Answer “no” if there are''
''open tasks that would prevent this incident or make mitigation easier if implemented.''
|
|
|-
|Were the people responding able to communicate effectively during the incident with the existing tooling?
|
|
|-
|Did existing monitoring notify the initial responders?
|
|
|-
|Were the engineering tools that were to be used during the incident, available and in service?
|
|
|-
|Were the steps taken to mitigate guided by an existing runbook?
|
|
|-
! colspan="2" align="right" |Total score (count of all “yes” answers above)
|
|
|}

Latest revision as of 14:44, 9 September 2022