Prevent CPU spike in task supervisor when heartbeat timeout exceeded #51023
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closes apache#50507 When the task supervisor's heartbeat timeout is exceeded, the `max_wait_time` calculation can become 0 or negative, causing `selector.select(timeout=0)` to run in a tight non-blocking loop that consumes 100% CPU as explained in the GitHub issue. Add minimum timeout of 0.01s in `_service_subprocess` to prevent this issue while maintaining responsive task monitoring. **Root Cause:** The issue occurs in the `_monitor_subprocess` method when: 1. `last_heartbeat_ago` becomes very large e.g., 100+ seconds due to bugs like network issues or due to bugs like apache#50500 2. The calculation `HEARTBEAT_TIMEOUT - last_heartbeat_ago * 0.75` becomes negative 3. `max(0, negative_value)` results in 0 4. `selector.select(timeout=0)` runs in a non-blocking tight loop
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…ut exceeded (apache#51023) (cherry picked from commit beb7b62) Co-authored-by: Kaxil Naik <kaxilnaik@gmail.com>
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…ut exceeded (apache#51023) (cherry picked from commit beb7b62) Co-authored-by: Kaxil Naik <kaxilnaik@gmail.com>
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closes #50507
When the task supervisor's heartbeat timeout is exceeded, the
max_wait_timecalculation can become 0 or negative, causingselector.select(timeout=0)to run in a tight non-blocking loop that consumes 100% CPU as explained in the GitHub issue.Add minimum timeout of 0.01s in
_service_subprocessto prevent this issue while maintaining responsive task monitoring.Root Cause:
The issue occurs in the
_monitor_subprocessmethod when:last_heartbeat_agobecomes very large e.g., 100+ seconds due to bugs like network issues or due to bugs like The task supervisor continues running indefinitely, even after the associated task process has completed #50500HEARTBEAT_TIMEOUT - last_heartbeat_ago * 0.75becomes negativemax(0, negative_value)results in 0selector.select(timeout=0)runs in a non-blocking tight loop^ Add meaningful description above
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