2023-05-22: RedisCacheServiceRailsRedisClientErrorSLOViolation
Customer Impact
1% of traffic.
Current Status
This appears to be a recurrence of a previous issue on May 17 regarding RedisCache client errors(2023-05-17: RedisCache Client error (#14406 - closed)). Both the web and API services were affected. An investigation was already underway to determine why Redis was becoming saturated. In an attempt to address the problem, the client connections were increased in a recent code change. However, it was discovered that the maxClients
setting was still at 40,000 instead of the intended 60,000. This discrepancy was caused by having two override_attributes
for the same attribute in different roles within the system.
📝 Summary for CMOC notice / Exec summary:
- Customer Impact: 1% of traffic
- Service Impact: ServiceRedisCache
- Impact Duration: start time UTC - end time UTC ( duration in minutes )
- Root cause: 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, Hot Patching or speeding up deployments. | 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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