chore: connection pipeline cache does not shrink #4491
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kostasrim
changed the title
| # pipeline_cache_bytes because it recycled too many messages, they won't gradually be released | ||
| # if one command (one connection out of `n` connections) dispatches async. Only 1 command out of | ||
| # n connections must be dispatched async and the pipeline won't gradually be relesed. | ||
| for i in range(30): |
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We cam drain the pipeline cache bytes once we stop dispatching async. But on large pool of connections only one command must dispatch async and then we need to internally reset the counter. If this pattern continues the size of the cache will remain constant and will not be released gradually.
Signed-off-by: kostas <[email protected]>
tests/dragonfly/connection_test.py
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| info = await good_client.info() | ||
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| # Drained | ||
| assert info["pipeline_cache_bytes"] == 0 |
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drained completely
| @@ -316,6 +314,36 @@ QueueBackpressure& GetQueueBackpressure() { | |||
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| thread_local vector<Connection::PipelineMessagePtr> Connection::pipeline_req_pool_; | |||
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| class PipelineCacheSizePaceMaker { | |||
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nit: maybe PipelineWatermarkTracker
| @@ -316,6 +314,36 @@ QueueBackpressure& GetQueueBackpressure() { | |||
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| thread_local vector<Connection::PipelineMessagePtr> Connection::pipeline_req_pool_; | |||
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| class PipelineCacheSizePaceMaker { | |||
| public: | |||
| bool WatermarkReached(size_t pipeline_sz) { | |||
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nit: maybe CheckAndUpdateWatermark
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| @dfly_args({"proactor_threads": 1}) | ||
| async def test_pipeline_cache_size(df_factory): |
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please add some comments on this test
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The main purpose of the pipeline cache is to reduce number of allocations. |
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also lets try to think when does this algorithm does not performs well |
Add test to show that pipeline cache won't shrink once it's filled if clients ping pong between async and sync dispatch
Proves #4461