2023-01-05: Redis-sidekiq sentinel loss of redundancy results in increased 500 errors
Current Status
between 07:42
and 08:12
we saw severe degradation on various operations on gitlab-com, we recovered most of the services after fixing the primary redis-sidekiq node, following that, there was a domino-like effect where some of the operations which started during the time of the incident didn't self-recover, the workaround for these issues was to recreate affected MRs, in some cases that wasn't enough, and users also needed to amend their commits or recreate their source branches.
Full recovery was made around 1150 when the remaining affected MRs were recovered to a workable state by manually enqueuing the NewMergeRequest
job for each of them, resulting in 404 errors on associated endpoints returning to a nominal rate.
📝 Summary for CMOC notice / Exec summary:
- Customer Impact: Customers received 500 errors when performing different operations on gitlab-com.
- Service Impact: ServiceAPI ServiceWeb ServiceCI Runners ServiceSidekiq ServiceRedis
- Impact Duration: 07:42 UTC - 08:12 UTC (30m)
- Root cause: RootCauseSPoF RootCauseExternal-Dependency
📚 References and helpful links
Recent Events (available internally only):
- Feature Flag Log - Chatops to toggle Feature Flags Documentation
- Infrastructure Configurations
- GCP Events (e.g. host failure)
Deployment Guidance
- Deployments Log | Gitlab.com Latest Updates
- Reach out to Release Managers for S1/S2 incidents to discuss Rollbacks and/or Hot Patching | Rollback Runbook | Hot Patch Runbook
Use the following links to create related issues to this incident if additional work needs to be completed after it is resolved:
- Corrective action ❙ Infradev
- Incident Review ❙ Infra investigation followup
- Confidential Support contact ❙ QA investigation
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