How the InnoDB master thread works

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void Master_thread () {goto loop;loop: for(intI=0;i<Ten; i++) {Thread_sleep (1)//Sleep 1 second--> per second (load is delayed in case)     DoLog buffer flush to disk//redo log buffers are flushed to disk, even if the transaction is not committed (always)    if(Last_ten_second_ios <5% innodb_io_capacity)//if the current number of 10 times is less than (5% * 200=10) (innodb_io_capacity default value is $)         DoMerger5% innodb_io_capacity Insert Buffer//perform 10 Merge Insert buffering operations (5% * 200=10)    if(buf_get_modified_ratio_pct > innodb_max_dirty_pages_pct)//if the dirty page ratio in the buffer pool is greater than innodb_max_dirty_pages_pct (default is 75 o'clock)         DoBuffer Pool Plush -% innodb_io_capacity Dirty page//Refresh 200 dirty pages to disk    Else ifEnable Adaptive flush//If you open an account, adaptive refresh         DoBuffer pool Flush Desired Amount Dirty page//determine the most appropriate number of dirty pages to refresh by judging the speed at which the redo log is generated    if(No user activity)//If there is currently no user activityGoto Backgroud Loop//Skip to Background loop}//operations performed every 10 secondsif(Last_ten_second_ios < innodb_io_capacity)//if the number of disk IO times in the past 10 is less than the set innodb_io_capacity value (by default)     DoBuffer Pool Flush -% innodb_io_capacity Dirty page//refreshes the number of dirty pages as innodb_io_capacity (by default) DoMerger5% innodb_io_capacity Insert Buffer//Merge Insert buffer is innodb_io_capacity 5% (10) (always) DoLog buffer flush to disk//redo log buffers are flushed to disk, even if the transaction is not committed (always) DoFull purge//Delete useless undo page (always)if(Buf_get_modified_ratio_pct > -%)//if the ratio of WINS pages in the buffer pool is greater than 70%     DoBuffer Pool Flush -% innodb_io_capacity Dirty page//Refresh 200 dirty pages to diskElse     DoBuffer Pool FlushTen% innodb_io_capacity Dirty page//Otherwise refresh 20 dirty pages to diskgoto Loopbackgroud Loop://Background Loop DoFull purge//Delete useless undo page (always) DoMerger5% innodb_io_capacity Insert Buffer//Merge Insert buffer is innodb_io_capacity 5% (10) (always)ifNot idle://if it is not idle, jump back to the main loop, and if idle, jump into the flush loopGoto Loop://Skip to main loopElse: Goto flush Loopflush Loop://Refresh Loop Dobuf_get_modified_ratio_pct Pool Flush -% innodb_io_capacity Dirty page//Refresh 200 dirty pages to diskif(buf_get_modified_ratio_pct > innodb_max_dirty_pages_pct)//if the dirty page ratio in the buffer pool is greater than the value of innodb_max_dirty_pages_pct (default 75%)Goto Flush Loop//skip to refresh cycle, refresh dirty pages continuously until eligibleGoto Suspend Loop//after completing the task of refreshing the dirty page, jump into the suspend loopsuspend Loop:suspend_thread ()//master thread hangs, waits for event to occurwaiting Eventgoto Loop;}

How the InnoDB master thread works