[Enhancement] Throttle scan to wait for topn filter #55660
+468
−8
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,108 @@ | ||
| // Copyright 2021-present StarRocks, Inc. All rights reserved. | ||
| // | ||
| // Licensed under the Apache License, Version 2.0 (the "License"); | ||
| // you may not use this file except in compliance with the License. | ||
| // You may obtain a copy of the License at | ||
| // | ||
| // https://www.apache.org/licenses/LICENSE-2.0 | ||
| // | ||
| // Unless required by applicable law or agreed to in writing, software | ||
| // distributed under the License is distributed on an "AS IS" BASIS, | ||
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | ||
| // See the License for the specific language governing permissions and | ||
| // limitations under the License. | ||
|
|
||
| #pragma once | ||
| #include <atomic> | ||
| #include <chrono> | ||
| #include <cstdint> | ||
| #include <functional> | ||
| #include <limits> | ||
|
|
||
| namespace starrocks::pipeline { | ||
| using std::chrono::milliseconds; | ||
| using std::chrono::steady_clock; | ||
| class TopnRfBackPressure { | ||
| enum Phase { PH_UNTHROTTLE, PH_THROTTLE, PH_PASS_THROUGH }; | ||
|
|
||
| template <typename T> | ||
| class ScaleGenerator { | ||
| public: | ||
| ScaleGenerator(T initial_value, T delta, double factor, std::function<bool(T)> next_cb) | ||
| : initial_value(initial_value), delta(delta), factor(factor), next_cb(next_cb), value(initial_value) {} | ||
|
|
||
| T limit() { return value; } | ||
| void next() { | ||
| value += delta; | ||
| value *= factor; | ||
| } | ||
| bool has_next() { return next_cb(value); } | ||
|
|
||
| private: | ||
| const T initial_value; | ||
| const T delta; | ||
| const double factor; | ||
| const std::function<bool(T)> next_cb; | ||
| T value; | ||
| }; | ||
|
|
||
| public: | ||
| void update_selectivity(double selectivity) { _current_selectivity = selectivity; } | ||
| void inc_num_rows(size_t num_rows) { _current_num_rows += num_rows; } | ||
|
|
||
| bool should_throttle() { | ||
| if (_phase == PH_PASS_THROUGH) { | ||
| return false; | ||
| } else if (!_round_limiter.has_next() || !_throttle_time_limiter.has_next() || !_num_rows_limiter.has_next() || | ||
| _current_selectivity <= _selectivity_lower_bound || | ||
| _current_total_throttle_time >= _throttle_time_upper_bound) { | ||
| _phase = PH_PASS_THROUGH; | ||
| return false; | ||
| } | ||
|
|
||
| if (_phase == PH_UNTHROTTLE) { | ||
| if (_current_num_rows <= _num_rows_limiter.limit()) { | ||
| return false; | ||
| } | ||
| _phase = PH_THROTTLE; | ||
| _current_throttle_deadline = duration_cast<milliseconds>(steady_clock::now().time_since_epoch()).count() + | ||
| _throttle_time_limiter.limit(); | ||
| return true; | ||
| } else { | ||
| auto now = duration_cast<milliseconds>(steady_clock::now().time_since_epoch()).count(); | ||
| if (now < _current_throttle_deadline) { | ||
| return true; | ||
| } | ||
| _phase = PH_UNTHROTTLE; | ||
| _current_num_rows = 0; | ||
| _current_total_throttle_time += _throttle_time_limiter.limit(); | ||
| _round_limiter.next(); | ||
| _throttle_time_limiter.next(); | ||
| _num_rows_limiter.next(); | ||
| return false; | ||
| } | ||
| } | ||
|
|
||
| TopnRfBackPressure(double selectivity_lower_bound, int64_t throttle_time_upper_bound, int max_rounds, | ||
| int64_t throttle_time, size_t num_rows) | ||
| : _selectivity_lower_bound(selectivity_lower_bound), | ||
| _throttle_time_upper_bound(throttle_time_upper_bound), | ||
| _round_limiter(0, 1, 1.0, [max_rounds](int r) { return r < max_rounds; }), | ||
| _throttle_time_limiter(throttle_time, 0, 1.0, [](int64_t) { return true; }), | ||
| _num_rows_limiter(num_rows, 0, 2.0, [](size_t n) { return n < std::numeric_limits<size_t>::max() / 2; }) { | ||
| } | ||
|
|
||
| private: | ||
| const double _selectivity_lower_bound; | ||
| const int64_t _throttle_time_upper_bound; | ||
| Phase _phase{PH_UNTHROTTLE}; | ||
| ScaleGenerator<int> _round_limiter; | ||
| ScaleGenerator<int64_t> _throttle_time_limiter; | ||
| ScaleGenerator<int64_t> _num_rows_limiter; | ||
| int64_t _current_throttle_deadline{-1}; | ||
| int64_t _current_total_throttle_time{0}; | ||
| size_t _current_num_rows{0}; | ||
| double _current_selectivity{1.0}; | ||
| }; | ||
|
|
||
| } // namespace starrocks::pipeline | ||
|
There was a problem hiding this comment. The most risky bug in this code is: You can modify the code like this: #include <chrono> // add this to the includes to use std::chrono_literals
if (_phase == PH_UNTHROTTLE) {
if (_current_num_rows <= _num_rows_limiter.limit()) {
return false;
}
_phase = PH_THROTTLE;
_current_throttle_deadline =
(steady_clock::now() + milliseconds(_throttle_time_limiter.limit())).time_since_epoch().count();
return true;
} |
||
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.
Oops, something went wrong.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
The most risky bug in this code is:
Potential segmentation fault due to a null pointer dereference when accessing
runtime_bloom_filters().You can modify the code like this: