feat(query): add spill backoff with sleep for low-memory queries under global pressure#19655
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dqhl76 wants to merge 5 commits intodatabendlabs:mainfrom
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feat(query): add spill backoff with sleep for low-memory queries under global pressure#19655dqhl76 wants to merge 5 commits intodatabendlabs:mainfrom
dqhl76 wants to merge 5 commits intodatabendlabs:mainfrom
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…r global pressure When global memory pressure triggers spill but the current query's memory usage is low, sleep with exponential backoff before spilling to give other queries a chance to release memory. Rename low_query_threshold to low_query_memory_bytes for clarity and add observability logging.
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Summary
When global memory pressure triggers spilling, low-memory queries can now sleep with exponential backoff before actually spilling. This gives the system time to reclaim memory from heavier queries, avoiding unnecessary spill I/O for lightweight queries that aren't major contributors to memory pressure.
Controlled by two new settings:
spill_global_backoff_max_sleep_ms— Maximum total sleep time (in milliseconds) for one spill decision under global-pressure backoff. Default:2000.min_query_memory_usage— A query is considered low-memory when its memory usage in bytes is at or below this threshold. Default:0(disabled).Backoff uses exponential sleep starting at 200ms, doubling each attempt, capped by the remaining sleep budget. Once the budget is exhausted, the query spills normally.
Tests
Type of change
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