2023-02-27: The shard_catchall SLI of the sidekiq service (`main` stage) has an apdex violating SLO: 92.04%

Current Status

A specific worker class was instantiated thousands of times, causing a bottleneck for other user work in an entire sidekiq processing shard.

More information will be added as we investigate the issue. For customers believed to be affected by this incident, please subscribe to this issue or monitor our status page for further updates.

📝 Summary for CMOC notice / Exec summary:

1. Customer Impact: Site wide slowness of Merge Request processing and other jobs
2. Service Impact: ServiceSidekiq
3. Impact Duration: 1815 utc - 1745 utc = about 30 minutes
4. Root cause: RootCauseNaive-Traffic RootCauseSaturation

📚 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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