Optimize fail-fast check to avoid loading SerializedDAG
#56694
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When a task fails and ``fail_fast`` is enabled, the system needs to stop remaining tasks. Previously, this required loading the entire 5-50 MB SerializedDAG for every task failure to check the ``fail_fast`` setting. This change adds `fail_fast` column to the dag table and checks it with a simple database lookup first. The `SerializedDAG` is only loaded when `fail_fast=True` (affecting ~1% of DAGs), avoiding unnecessary memory and I/O overhead in 99% of cases.
kaxil
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amoghrajesh
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Oct 16, 2025
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Nice optimisation, I had given it a thought but didn't do it !
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When a task fails and
fail_fastis enabled, the API-server needs to stop remaining tasks. Previously, this required loading the entire 5-50 MB SerializedDAG for every task failure (although it comes from cache -- but it is likely that if multiple replicas are run -- it might not have it in local cache) to check thefail_fastsetting.This change adds
fail_fastcolumn to the dag table and checks it with a simple database lookup first. TheSerializedDAGis only loaded whenfail_fast=True(affecting ~1% of DAGs), avoiding unnecessary memory and I/O overhead in 99% of cases.^ Add meaningful description above
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