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Changed lock_object_storage_task_distribution_ms value to 500
Also updated settings description, and minor fix in settings history
1 parent 1baa927 commit ed68e8b

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2 files changed

+17
-3
lines changed

2 files changed

+17
-3
lines changed

src/Core/Settings.cpp

Lines changed: 12 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -6888,8 +6888,18 @@ Cache the list of objects returned by list objects calls in object storage
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DECLARE(Bool, distributed_plan_optimize_exchanges, true, R"(
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Removes unnecessary exchanges in distributed query plan. Disable it for debugging.
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)", 0) \
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DECLARE(UInt64, lock_object_storage_task_distribution_ms, 0, R"(
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In object storage distribution queries do not distibute tasks on non-prefetched nodes until prefetched node is active.
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DECLARE(UInt64, lock_object_storage_task_distribution_ms, 500, R"(
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In object storage distribution queries do not distribute tasks on non-prefetched nodes until prefetched node is active.
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Determines how long the free executor node (one that finished processing all of it assigned tasks) should wait before "stealing" tasks from queue of currently busy executor nodes.
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Possible values:
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- 0 - steal tasks immediately after freeing up.
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- >0 - wait for specified period of time before stealing tasks.
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Having this `>0` helps with cache reuse and might improve overall query time.
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Because busy node might have warmed-up caches for this specific task, while free node needs to fetch lots of data from S3.
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Which might take longer than just waiting for the busy node and generate extra traffic.
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)", EXPERIMENTAL) \
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DECLARE(String, distributed_plan_force_exchange_kind, "", R"(
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Force specified kind of Exchange operators between distributed query stages.

src/Core/SettingsChangesHistory.cpp

Lines changed: 5 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -67,7 +67,11 @@ const VersionToSettingsChangesMap & getSettingsChangesHistory()
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/// controls new feature and it's 'true' by default, use 'false' as previous_value).
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/// It's used to implement `compatibility` setting (see https://github.com/ClickHouse/ClickHouse/issues/35972)
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/// Note: please check if the key already exists to prevent duplicate entries.
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addSettingsChanges(settings_changes_history, "25.6.5.2000",
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addSettingsChanges(settings_changes_history, "25.6.5.20364",
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{
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{"lock_object_storage_task_distribution_ms", 500, 500, "Raised the value to 500 to avoid hoping tasks between executors."},
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});
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addSettingsChanges(settings_changes_history, "25.6.5.20000",
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{
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{"allow_experimental_database_iceberg", false, true, "Turned ON by default for Antalya"},
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{"allow_experimental_database_unity_catalog", false, true, "Turned ON by default for Antalya"},

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