Prevent query from deadlocking when task output buffer is full #14948
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When query is of shape:
SourceStage
\
PartitionedStage(broadcast output buffer)
/ \
ProbeStage BuildStage
Then it might happen that task output buffer for
PartitionedStage gets full blocking upstream stages
(ProbeStage and BuildStage).
Previously, phased scheduled did not schedule SourceStage
in such situation because PartitionedStage was already considered
completed.
This commit makes PhasedExecutionSchedule#unblockStagesWithFullOutputBuffer
check to be run for all stages (including scheduled, but running stages).
losipiuk
reviewed
Nov 8, 2022
core/trino-main/src/main/java/io/trino/execution/scheduler/policy/PhasedExecutionSchedule.java
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losipiuk
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Nov 8, 2022
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When query is of shape:
Then it might happen that task output buffer for
PartitionedStagegets full blocking upstream stages (ProbeStageandBuildStage).Previously, phased scheduled did not schedule
SourceStagein such situation becausePartitionedStagewas already considered completed.This commit makes
PhasedExecutionSchedule#unblockStagesWithFullOutputBuffercheck to be run for all stages (including scheduled, but running stages).