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      The writing of modified InnoDB data pages to data files should be overhauled. See some of the comments in MDEV-15058.

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            It appears that XtraDB used to disable the single-page flushing when using a larger buffer pool, via the Boolean-disguised-as-enum parameter innodb_empty_free_list_algorithm=BACKOFF. The logic would sometimes fail, as reported in MDEV-16339.

            I think that we should consider removing the single-page flushing nevertheless. Perhaps there could be active signaling between the page cleaner and the buf_LRU_get_free_block(), instead of passive sleeping?

            marko Marko Mäkelä added a comment - It appears that XtraDB used to disable the single-page flushing when using a larger buffer pool, via the Boolean-disguised-as-enum parameter innodb_empty_free_list_algorithm=BACKOFF . The logic would sometimes fail, as reported in MDEV-16339 . I think that we should consider removing the single-page flushing nevertheless. Perhaps there could be active signaling between the page cleaner and the buf_LRU_get_free_block() , instead of passive sleeping?

            Now that most of the work has been completed in MDEV-23399 and MDEV-23855, I think that the main work to be done will be in MDEV-12227, MDEV-23756 and possibly other tickets that have been linked as related.

            Because this is mostly an umbrella task, having an estimate is not too meaningful.

            marko Marko Mäkelä added a comment - Now that most of the work has been completed in MDEV-23399 and MDEV-23855 , I think that the main work to be done will be in MDEV-12227 , MDEV-23756 and possibly other tickets that have been linked as related. Because this is mostly an umbrella task, having an estimate is not too meaningful.

            I adjusted the priority to "Major", eventhough it is probably "minor" , for the rest of the things left there.

            wlad Vladislav Vaintroub added a comment - I adjusted the priority to "Major", eventhough it is probably "minor" , for the rest of the things left there.

            I think that most of this has already been done. One remaining tweak is MDEV-26827. We failed to observe any improvement with it; in fact, a small regression was observed. So, it will need some additional work.

            marko Marko Mäkelä added a comment - I think that most of this has already been done. One remaining tweak is MDEV-26827 . We failed to observe any improvement with it; in fact, a small regression was observed. So, it will need some additional work.

            After MDEV-26055 and MDEV-26827 have been completed, there is not much that can be improved in this area. I can only think of MDEV-11378, submitting scatter-gather write requests instead of multiple single-page write requests.

            marko Marko Mäkelä added a comment - After MDEV-26055 and MDEV-26827 have been completed, there is not much that can be improved in this area. I can only think of MDEV-11378 , submitting scatter-gather write requests instead of multiple single-page write requests.

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              marko Marko Mäkelä
              marko Marko Mäkelä
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