MediaWiki Event Enrichment/Incidents/2023 07 19 enrich job outage
document status: in-review
Summary
| Incident ID | 2023 07 19 enrich job outage | Start | 2023-07-19 18:50:30 |
|---|---|---|---|
| Task | End | 2023-07-19 20:30:00 | |
| People paged | 0 | Responder count | 2 |
| Coordinators | GModena | Affected metrics/SLOs | Flink Taskmanager uptime, service availability. |
| Impact | The mw-page-content-change-enrich application (eqiad) has not been producing enriched events during the outage. | ||
Description
An enriched message exceeding Kafka's max.request.size caused the application's Kafka producer to crash. This in turn resulted in a Flink Taskmanager shutdown.
Full stacktrace is available at: https://logstash.wikimedia.org/app/discover#/doc/0fade920-6712-11eb-8327-370b46f9e7a5/ecs-k8s-1-1.11.0-6-2023.29?id=EeKfdIkB6U_kV85ADO_D
HA tried to restart the application but the restart strategy, failed more than restart-strategy.fixed-delay.attempts times.
A manual application restart was required. The offending message has seemingly been discarded.
A fix is proposed in task T342399
Timeline
- 20:10:38 UTC: GModena opens thread to ACK the outage in #data-platform-engineering
- 20:20:24 UTC: TChin identifies the root cause of the issue (
- 20:24:00 UTC: GModena manually restarts the application
- 20:44:00 UTC: GModena silences Kafka Consumer lag alerts while the application catches up with queues messages.
Detection
GModena and TChin reacted to alerts triggered by degrading SLIs.
Conclusions
- Application is running.
- We know what needs to be fixed.
What went well?
What went poorly?
Where did we get lucky?
Links to relevant documentation
Actionables
- increase max message size allowed by Kafka
- Filter out messages larger than the max allowed size; task T342399