Retry ECS RunTask on AGENT error which can happen as its normal operation #1723
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Problem
As described in Amazon ECS events - Amazon Elastic Container Service, the ECS container agent disconnects and reconnects several times per hour as a part of its normal operation.
So, ECS RunTask API can fail with
AGENT
reason when it's requested in the middle of the reconnection. ECS RunTask API callers should handle this situation.Currently, EcsCommandExecutor, which relies on ECS RunTask API, doesn't consider the
AGENT
error and simply fails with a RuntimeException"Submitted task could not be found"
.digdag/digdag-standards/src/main/java/io/digdag/standards/command/EcsCommandExecutor.java
Lines 135 to 148 in a1d842c
digdag/digdag-standards/src/main/java/io/digdag/standards/command/EcsCommandExecutor.java
Lines 539 to 547 in a1d842c
What this PR does
This PR tries to handle the
AGENT
error by simply retrying a RunTask API call after a few seconds.This approach has been confirmed to be effective to handle the random agent reconnections in our production environment.
On reproduction
It's difficult to establish stable steps to reproduce this issue due to its randomness but it should be easy to see what happens when RunTask failed with
AGENT
error and why it should be handled.