2021-11-16 The sshServices SLI of the frontend service (`main` stage) has an apdex violating SLO

Current Status

Update 2021-11-16 11:30:00

We decided to create a silence for two weeks and to open an infradev issue about timing out connections waiting in the Gitaly queue for more than 10s.

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Update 2021-11-16 10:30:00

Our current hypothesis is that a single user is sending a lot of ssh requests to a single project. It is then being rate limited by Gitaly and that translates to connections waiting to be served by Gitaly. That additional waiting time translates to higher latency which then has an impact on our SLI.

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Apdex has been slightly degraded for about 3 hours now, and we've hit a slow-burn threshold:

This is a slight performance issue, not errors, and may be already recovering, although it'll take a few minutes to confirm that.

Timeline

Recent Events (available internally only):

• Deployments
• Feature Flag Changes
• Infrastructure Configurations
• GCP Events (e.g. host failure)

All times UTC.

2021-11-16

• 04:53 - @cmiskell declares incident in Slack.
• 08:06 - @sean_carroll incident is being investigated by groupsource code

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