2025-12-06: rails_request error rate in ai-assisted service main stage is violating SLO

rails_request error rate in ai-assisted service main stage is violating SLO (Severity 4)

Problem: The ai-assisted service has experienced 500 errors due to database issues with certain Unicode characters in JSON data, resulting in an elevated error rate.

Impact: The ai-assisted service in the main stage had a rails_request error rate of 4.826% over the past hour, exceeding the SLO. Traffic levels are low and the AI Workflow feature continues to work as expected.

Causes: 500 errors are caused by unsupported Unicode escape sequences (\u0000 characters) in JSON data, which trigger PG::UntranslatableCharacter database errors. This is a known issue tracked in a follow-up work item.

Response strategy: We have silenced the alert until Monday since the issue is not critical, service functionality is unaffected, and a follow-up work item has been created to track this problem.

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This ticket was created to track INC-6142, by incident.io 🔥