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Date

Authors

James Harris Yafang Deng Jayanta Saha

Status

Jira Legacy
serverSystem JIRA
serverId4c843cd5-e5a9-329d-ae88-66091fcfe3c7
keyTIS21-4367

Summary

ndw-etl-prod task was not run on Apr 11

Impact

Caused a failure of the User Refresh job on NDW.

End users would see the stale data which were 24 hours before.

Non-technical Description

The push of TIS data to NDW was not run on Apr 11.

...

Trigger

  • Nightly data push from TIS to NDWDue to AWS capacity, we were not able to start the task.

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Detection

  • Email from NDW team in the morning of 11/04/2023

  • In #monitoring-ndw channel on Slack, no notifications found for ndw-etl-prod task:

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  • 04:03 - Since then, no more notifications had been received for the overnight ndw etl jobs.

  • 11:32 - NDW team emailed about the failure

  • 12:07 - James redirected the email that push of TIS data into NDW failed

  • 12:40 - Yafang found no logs found on ndw-etl-prod in the midnight

  • 13:02 - Andy D found the event bridge triggered the task and the service considered itself healthy, but no record for the task on prod

  • 14:26 - Yafang & Jay triggered the task ndw-etl-prod manually

  • 14:56 - The task has been run and exited on etl-prod successfully

  • 15:11 - James let Guy know and NDW started their jobs.

  • 12, 13:45 - Guy confirmed there were no subsequent issues.

...

  • We expect the ndw-etl-prod job to be triggered by the AWS eventbridge rule every day at 2am UTC.

  • From the metrics, the everntbridge rule was triggered on Apr 11, but there’re no logs found on Cloudwatch. And from the ECSStoppedTasksEvent, we can also find the ndw-etl-prod task was not started.

  • The CloudTrail event history shows the reason of failure: "Capacity is unavailable at this time. Please try again later or in a different availability zone"

  • We could ask AWS why there was no capacity. The AWS Service Status indicates there was no failure or maintenance reducing expected capacity.

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Action Items

Action Items

Comments

Owner

Monitor CloudTrail event. Once we get this error, pick up another time to restart the task.

Alert to Slack channel if runTask fails.

Yafang Deng

Change config to use a wider choice of availability zones.

Other stuff we won’t do, at least for now, given the assumption about low probability of re-occurrence:

  • Automated retries

  • A separate job to check that the ETL has run for each environment

Lessons Learned