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Diffstat (limited to 'src/mongo/db/query/query_stats/rate_limiting.h')
| -rw-r--r-- | src/mongo/db/query/query_stats/rate_limiting.h | 126 |
1 files changed, 0 insertions, 126 deletions
diff --git a/src/mongo/db/query/query_stats/rate_limiting.h b/src/mongo/db/query/query_stats/rate_limiting.h deleted file mode 100644 index 66e38d7119b..00000000000 --- a/src/mongo/db/query/query_stats/rate_limiting.h +++ /dev/null @@ -1,126 +0,0 @@ -/** - * Copyright (C) 2022-present MongoDB, Inc. - * - * This program is free software: you can redistribute it and/or modify - * it under the terms of the Server Side Public License, version 1, - * as published by MongoDB, Inc. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * Server Side Public License for more details. - * - * You should have received a copy of the Server Side Public License - * along with this program. If not, see - * <http://www.mongodb.com/licensing/server-side-public-license>. - * - * As a special exception, the copyright holders give permission to link the - * code of portions of this program with the OpenSSL library under certain - * conditions as described in each individual source file and distribute - * linked combinations including the program with the OpenSSL library. You - * must comply with the Server Side Public License in all respects for - * all of the code used other than as permitted herein. If you modify file(s) - * with this exception, you may extend this exception to your version of the - * file(s), but you are not obligated to do so. If you do not wish to do so, - * delete this exception statement from your version. If you delete this - * exception statement from all source files in the program, then also delete - * it in the license file. - */ - -#pragma once - -#include "mongo/util/clock_source.h" -#include "mongo/util/concurrency/mutex.h" -#include "mongo/util/system_clock_source.h" - -namespace mongo { - -/** - * Rate limiting is used to put a bound on the number of requests to a certain resource over a fixed - * time window. This implementation is approximate in the sense that it may permit the bound to - * exceeded. The bound is approximate as a trade off to reduce contention on internal resources. - */ -class RateLimiting { - using RequestCount = uint32_t; - -public: - /* - * Constructor for a rate limiter. Specify the number of requests you want to take place, as - * well as the time period in milliseconds. - */ - RateLimiting(RequestCount samplingRate, - Milliseconds timePeriod = Seconds{1}, - ClockSource* clockSource = nullptr); - - /* - * Getter for the sampling rate. - */ - RequestCount getSamplingRate() { - return _samplingRate.load(); - } - - /* - * Setter for the sampling rate. - */ - void setSamplingRate(RequestCount samplingRate) { - _samplingRate.store(samplingRate); - } - - /* - * A simple method for rate limiting. Returns false if we have reached the request limit for the - * current time window; otherwise, returns true and adds the request to the count for the - * current window. If we have passed the end of the previous window, the slate is wiped clean. - */ - bool handleRequestFixedWindow(); - - /* - * A method that ensures a more steady rate of requests. Rather than only looking at the current - * time block, this method simulates a sliding window to estimate how many requests occurred in - * the last full time period. Like the above, returns whether the request should be handled, and - * resets the window if enough time has passed. - */ - bool handleRequestSlidingWindow(); - -private: - /* - * Resets the current window if it has ended. Returns the current time. This must be called in - * the beginning of each handleRequest...() method. - */ - Date_t tickWindow(); - - /* - * Clock source used to track time. - */ - ClockSource* const _clockSource; - - /* - * Sampling rate is the bound on the number of requests we want to admit per window. - */ - AtomicWord<RequestCount> _samplingRate; - - /* - * Time period is the window size in ms. - */ - const Milliseconds _timePeriod; - - /* - * Window start. - */ - Date_t _windowStart; - - /* - * Count of requests handled in the previous window. - */ - RequestCount _prevCount; - - /* - * Count of requests handled in the current window. - */ - RequestCount _currentCount; - - /* - * Mutex used when reading/writing the window. - */ - SimpleMutex _windowMutex; -}; -} // namespace mongo |
