fix: avoid flush too many small sst file #1003
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MichaelLeeHZ
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ShiKaiWi
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Jun 20, 2023
ShiKaiWi
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Jun 20, 2023
MichaelLeeHZ
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MichaelLeeHZ
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ShiKaiWi
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Jun 27, 2023
dust1
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Aug 9, 2023
## Rationale Currently, we attempt to flush the table that consumes the maximum memory when the system memory usage limit is reached for either `space_write_buffer_size` or `db_write_buffer_size`. However, if the target table is currently undergoing flushing, its memory usage will not be released, causing the `preprocess_flush` (freeze small memtables) function to be repeatedly triggered. This can result in the creation of many small SST files, potentially causing query issues. ## Detailed Changes * Move `preprocess_flush` into `flush_job` * Split `swith_memtables_or_suggest_duration` into 2 methods, and make `swith_memtables` return maxium sequence number. ## Test Plan
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tanruixiang
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Dec 21, 2023
## Rationale #1003 tries to avoid frequent flush requests which may generate massive small ssts, but the write stall is also removed in the normal write path. ## Detailed Changes Introduce the `min_flush_interval` to avoid frequent flush requests and recover the write stall mechanism. ## Test Plan Add unit tests for the frequent flush check.
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Rationale
Currently, we attempt to flush the table that consumes the maximum memory when the system memory usage limit is reached for either
space_write_buffer_sizeordb_write_buffer_size. However, if the target table is currently undergoing flushing, its memory usage will not be released, causing thepreprocess_flush(freeze small memtables) function to be repeatedly triggered. This can result in the creation of many small SST files, potentially causing query issues.Detailed Changes
preprocess_flushintoflush_jobswith_memtables_or_suggest_durationinto 2 methods, and makeswith_memtablesreturn maxium sequence number.Test Plan