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  1. MariaDB Server
  2. MDEV-26138

innodb_flush_log_at_trx_commit=3 doesn't flush

Details

    Description

      "Since 10.2 this code was refactored to have switches in descending
      order, so value of 3 for innodb_flush_log_at_trx_commit is behaving
      the same as value of 2, that is no FSYNC is being enforced during
      COMMIT phase. The switch should however not be empty and cases 2 and 3
      should not have the identical contents."

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        Issue Links

          relates to

          Task - A task that needs to be done. MDEV-232 Remove one fsync() inside engine's commit() method

          • Major - Major loss of function.
          • Closed
          links to

          Web Link gh pr 1873

          Activity

            Ascending order - Click to sort in descending order
            marko Marko Mäkelä added a comment -

            The parameter value 3 was introduced in MDEV-232, and it has been effectively treated as innodb_flush_log_at_trx_commit=2 since the MariaDB 10.2.2 alpha release.

            Would an alternative fix be acceptable? That is, let us remove the value 3 and have the server issue a warning that the value was clamped to 2? That would basically document the status quo. Does anyone really need the innodb_flush_log_at_trx_commit=3 behaviour that was introduced in MDEV-232?

            3 (flush to disk at prepare and at commit, slower and usually redundant)

            marko Marko Mäkelä added a comment - The parameter value 3 was introduced in MDEV-232 , and it has been effectively treated as innodb_flush_log_at_trx_commit=2 since the MariaDB 10.2.2 alpha release. Would an alternative fix be acceptable? That is, let us remove the value 3 and have the server issue a warning that the value was clamped to 2? That would basically document the status quo. Does anyone really need the innodb_flush_log_at_trx_commit=3 behaviour that was introduced in MDEV-232 ? 3 (flush to disk at prepare and at commit, slower and usually redundant)
            marko Marko Mäkelä added a comment -

            Because the documentation string for innodb_flush_log_at_trx_commit implies that the value 3 is ‘stronger’ than the value 1, it would seem wrong to keep treating it in a similar way as the ‘weaker’ value 2.

            Overall, it seems to be simplest to fix the parameter to work as documented.

            marko Marko Mäkelä added a comment - Because the documentation string for innodb_flush_log_at_trx_commit implies that the value 3 is ‘stronger’ than the value 1, it would seem wrong to keep treating it in a similar way as the ‘weaker’ value 2. Overall, it seems to be simplest to fix the parameter to work as documented.

            People

              marko Marko Mäkelä
              danblack Daniel Black
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                Resolved:

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