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imported>Samtar
 
imported>RhinosF1
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| task = T315350
| task = T315350
| paged-num = 0
| paged-num = 0
| responders-num = 4
| responders-num = 8
| coordinators =  
| coordinators = TheresNoTime
| start = 2022-08-16 17:57:00
| start = 2022-08-16 17:57:00
| end = 2022-08-17 00:57:00
| end = 2022-08-17 00:57:00
| metrics = No relevant SLOs exist
| metrics = beta has a best effort SLA
| impact = All sites within the Beta Cluster were unavailable, which affected CI workflows
| impact = All sites within the Beta Cluster were unavailable, which affected CI workflows
}}
}}
<!-- Reminder: No private information on this page! -->
<!-- Reminder: No private information on this page! -->


After an inadvertent restart of some WMCS cloudvirts and their associated VMs, all sites within the Beta Cluster (e.g. https://meta.wikimedia.beta.wmflabs.org/wiki/Main_Page) failed to load, with ''<code>Error: 502, Next Hop Connection Failed</code>'' — this persisted post-restart of the relevant VMs.
After an inadvertent restart of some WMCS cloudvirts and their associated VMs, all sites within the Beta Cluster (e.g. https://meta.wikimedia.beta.wmflabs.org/wiki/Main_Page) failed to load, with ''<code>Error: 502, Next Hop Connection Failed</code>'' — this persisted post-restart of the relevant VMs.


Drafting: possibly an apache config/puppet failure (https://phabricator.wikimedia.org/T315350#8159826), restarting trafficserver seems to have fixed it (https://phabricator.wikimedia.org/T315350#8159954)
Drafting: possibly an apache config/puppet failure (https://phabricator.wikimedia.org/T315350#8159826), restarting trafficserver seems to have fixed it (https://phabricator.wikimedia.org/T315350#8159954)
The incident was complicated by the lack of Beta Cluster's maintenance meaning ongoing "normal" errors distracted from the cause.


<mark>Summary of what happened, in one or two paragraphs. Avoid assuming deep knowledge of the systems here, and try to differentiate between proximate causes and root causes.</mark>
<mark>Summary of what happened, in one or two paragraphs. Avoid assuming deep knowledge of the systems here, and try to differentiate between proximate causes and root causes.</mark>


'''Documentation''':
{{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.''
 
*00:00 (TODO) '''OUTAGE BEGINS'''
*00:04 (Something something)
*00:06 (Voila) '''OUTAGE ENDS'''
*00:15 (post-outage cleanup finished)
 
<!-- Reminder: No private information on this page! -->
<mark>TODO: Clearly indicate when the user-visible outage began and ended.</mark>
 
==Detection==
* User reports
* CI errors from beta sync
 
<mark>Copy the relevant alerts that fired in this section.</mark>
 
<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>
 
<mark>TODO: If human only, an actionable should probably be to "add alerting".</mark>
 
==Conclusions==
 
===What went well?===
 
* A number of volunteers were available to triage
 
 
<mark>(Use bullet points) for example: automated monitoring detected the incident, outage was root-caused quickly, etc</mark>
 
===What went poorly?===
 
* lack of fast response from people with sufficient knowledge
* beta is already broken in weird and wonderful ways
 
<mark>What weaknesses did we learn about and how can we address them?</mark>
<mark>(Use bullet points) for example: documentation on the affected service was unhelpful, communication difficulties, etc</mark>
 
===Where did we get lucky?===
 
* No deployments were affected
* Beta wasn't needed due to test/replicate production issues during the time.
 
<mark>(Use bullet points) for example: user's error report was exceptionally detailed, incident occurred when the most people were online to assist, etc</mark>
 
===How many people were involved in the remediation?===
 
* 3 Volunteers
* 2 Release Engineers
* 2 SRE - 1 Search Platform, 1 ServiceOps
* 1 WMCS admin
 
 
<mark>(Use bullet points) for example: 2 SREs and 1 software engineer troubleshooting the issue plus 1 incident commander</mark>
 
==Links to relevant documentation==
 
*…
*…


<mark>Link to relevant source code, graphs, or logs</mark>
<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==
==Actionables==


*<s>Consider monitoring the Beta Cluster</s> (?)
* [[phab:T315379|logspam watch broken on beta]] {{done}}
*[[:phab:T315394|Remove two cherry-picked reverts from deployment-puppetmaster04 (T315394)]]
* [[phab:T315394|Remove two cherry-picked reverts from deployment-puppetmaster04]]
*[[:phab:T315395|Rebase & merge or re-cherry-pick 668701 on deployment-puppetmaster04 (T315395)]]
* [[phab:T315395|Rebase & merge or re-cherry-pick 668701 on deployment-puppetmaster04]]
* [[phab:T315386|Replace certificate on deployment-elastic09.deployment-prep.eqiad1.wikimedia.cloud]]


<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>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>
<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==
==Scorecard==
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|-
|-
|Were the people who responded prepared enough to respond effectively
|Were the people who responded prepared enough to respond effectively
|yes
|no
|
|
|-
|-
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|-
|-
|Were pages routed to the correct sub-team(s)?
|Were pages routed to the correct sub-team(s)?
|no
| N/A
|
|
|-
|-
|Were pages routed to online (business hours) engineers?  ''Answer “no” if engineers were paged after business hours.''
|Were pages routed to online (business hours) engineers?  ''Answer “no” if engineers were paged after business hours.''
|no
| N/A
|
|
|-
|-
! rowspan="5" |Process
! rowspan="5" |Process
|Was the incident status section actively updated during the incident?
|Was the incident status section actively updated during the incident?
|yes
|no
|
|
|-
|-
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|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''
|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.''
''open tasks that would prevent this incident or make mitigation easier if implemented.''
|
|no
|
|
|-
|-
|Were the people responding able to communicate effectively during the incident with the existing tooling?
|Were the people responding able to communicate effectively during the incident with the existing tooling?
|
|yes
|
|
|-
|-
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|-
|-
|Were the engineering tools that were to be used during the incident, available and in service?
|Were the engineering tools that were to be used during the incident, available and in service?
|
|no
|
|
|-
|-
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|-
|-
! colspan="2" align="right" |Total score (count of all “yes” answers above)
! colspan="2" align="right" |Total score (count of all “yes” answers above)
|
|4/12
|
|
|}
|}

Revision as of 13:37, 17 August 2022

document status: draft

Summary

Incident metadata (see Incident Scorecard)
Incident ID 2022-08-16 Beta Cluster 502 Start 2022-08-16 17:57:00
Task T315350 End 2022-08-17 00:57:00
People paged 0 Responder count 8
Coordinators TheresNoTime Affected metrics/SLOs beta has a best effort SLA
Impact All sites within the Beta Cluster were unavailable, which affected CI workflows

After an inadvertent restart of some WMCS cloudvirts and their associated VMs, all sites within the Beta Cluster (e.g. https://meta.wikimedia.beta.wmflabs.org/wiki/Main_Page) failed to load, with Error: 502, Next Hop Connection Failed — this persisted post-restart of the relevant VMs.

Drafting: possibly an apache config/puppet failure (https://phabricator.wikimedia.org/T315350#8159826), restarting trafficserver seems to have fixed it (https://phabricator.wikimedia.org/T315350#8159954)

The incident was complicated by the lack of Beta Cluster's maintenance meaning ongoing "normal" errors distracted from the cause.

Summary of what happened, in one or two paragraphs. Avoid assuming deep knowledge of the systems here, and try to differentiate between proximate causes and root causes.

Timeline

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.

Consider including a graphs of the error rate or other surrogate.

Link to a specific offset in SAL using the SAL tool at https://sal.toolforge.org/ (example)

All times in UTC.

  • 00:00 (TODO) OUTAGE BEGINS
  • 00:04 (Something something)
  • 00:06 (Voila) OUTAGE ENDS
  • 00:15 (post-outage cleanup finished)

TODO: Clearly indicate when the user-visible outage began and ended.

Detection

  • User reports
  • CI errors from beta sync

Copy the relevant alerts that fired in this section.

Did the appropriate alert(s) fire? Was the alert volume manageable? Did they point to the problem with as much accuracy as possible?

TODO: If human only, an actionable should probably be to "add alerting".

Conclusions

What went well?

  • A number of volunteers were available to triage


(Use bullet points) for example: automated monitoring detected the incident, outage was root-caused quickly, etc

What went poorly?

  • lack of fast response from people with sufficient knowledge
  • beta is already broken in weird and wonderful ways

What weaknesses did we learn about and how can we address them? (Use bullet points) for example: documentation on the affected service was unhelpful, communication difficulties, etc

Where did we get lucky?

  • No deployments were affected
  • Beta wasn't needed due to test/replicate production issues during the time.

(Use bullet points) for example: user's error report was exceptionally detailed, incident occurred when the most people were online to assist, etc

How many people were involved in the remediation?

  • 3 Volunteers
  • 2 Release Engineers
  • 2 SRE - 1 Search Platform, 1 ServiceOps
  • 1 WMCS admin


(Use bullet points) for example: 2 SREs and 1 software engineer troubleshooting the issue plus 1 incident commander

Links to relevant documentation

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.

Actionables

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.

Add the #Sustainability (Incident Followup) and the #SRE-OnFIRE (Pending Review & Scorecard) Phabricator tag to these tasks.

Scorecard

Incident Engagement ScoreCard
Question Answer

(yes/no)

Notes
People Were the people responding to this incident sufficiently different than the previous five incidents? no
Were the people who responded prepared enough to respond effectively no
Were fewer than five people paged? yes
Were pages routed to the correct sub-team(s)? N/A
Were pages routed to online (business hours) engineers? Answer “no” if engineers were paged after business hours. N/A
Process Was the incident status section actively updated during the incident? no
Was the public status page updated? no
Is there a phabricator task for the incident? yes
Are the documented action items assigned? no
Is this incident sufficiently different from earlier incidents so as not to be a repeat occurrence? yes
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.

no
Were the people responding able to communicate effectively during the incident with the existing tooling? yes
Did existing monitoring notify the initial responders? no
Were the engineering tools that were to be used during the incident, available and in service? no
Were the steps taken to mitigate guided by an existing runbook? no
Total score (count of all “yes” answers above) 4/12