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  1. MariaDB Server
  2. MDEV-32663

mariadb filesystem size increasing for wp_options.ibd files

Details

    • Bug
    • Status: Open (View Workflow)
    • Major
    • Resolution: Unresolved
    • 10.6.15, 10.6.16, 10.6.17
    • 10.6
    • None
    • Ubuntu 20.04

    Description

      I'm in a situation with a wordpress site where a table wp_options keeps increasing in filesystem size really fast even though it only has 10000 records and we have to constantly optimize it to reduce the usage.

      It's my understanding that when records are constantly deleted / inserted they are not actually deleted from the ibd file but they're kind of soft-deleted.

      Thus the filesystem size on the file actually increases constantly reaching even 500G within 2 days.

      In order to fix the issue I need to actually see what is being written / deleted from the table constantly to find possible plugins that might be affecting it.

      I can safely assume it's wordpress transients however I can't say with certainty which type of transient is causing this bloat without examining the data.

      So in order to find this out I'm looking for ways to read the soft-deleted data from the bloated ibd file.

      I've tried a couple of tools like undrop-for-innodb but it's not yielding any results.

      Any ideas how I can read the mass of deleted data that's occupying the filesystem space?

      I also think that there should be a limit to the expansion of the table with deleted data. Like, why would a table of 20MBs in size need 500GB of deleted data in the filesystem?

      Attachments

        1. blob.zip
          11 kB
        2. historylenth.zip
          90 kB
        3. historylenth-1.zip
          301 kB
        4. history-list-length.zip
          842 kB
        5. sample.zip
          152 kB

        Issue Links

          Activity

            ioweb.gr Gabriel Tziotzis created issue -
            ioweb.gr Gabriel Tziotzis made changes -
            Field Original Value New Value
            Description I'm in a situation with a wordpress site where a table wp_options keeps increasing in filesystem size really fast even though it only has 10000 records and we have to constantly optimize it to reduce the usage.

            It's my understanding that when records are constantly deleted / inserted they are not actually deleted from the ibd file but they're kind of soft-deleted.

            Thus the filesystem size on the file actually increases constantly reaching even 500G within 2 days.

            In order to fix the issue I need to actually see what is being written / deleted from the table constantly to find possible plugins that might be affecting it.

            I can safely assume it's wordpress transients however I can't say with certainty which type of transient is causing this bloat without examining the data.

            So in order to find this out I'm looking for ways to read the soft-deleted data from the bloated ibd file.

            I've tried a couple of tools like undrop-for-innodb but it's not yielding any results.

            Any ideas how I can read the mass of deleted data that's occupying the filesystem space?
            I'm in a situation with a wordpress site where a table wp_options keeps increasing in filesystem size really fast even though it only has 10000 records and we have to constantly optimize it to reduce the usage.

            It's my understanding that when records are constantly deleted / inserted they are not actually deleted from the ibd file but they're kind of soft-deleted.

            Thus the filesystem size on the file actually increases constantly reaching even 500G within 2 days.

            In order to fix the issue I need to actually see what is being written / deleted from the table constantly to find possible plugins that might be affecting it.

            I can safely assume it's wordpress transients however I can't say with certainty which type of transient is causing this bloat without examining the data.

            So in order to find this out I'm looking for ways to read the soft-deleted data from the bloated ibd file.

            I've tried a couple of tools like undrop-for-innodb but it's not yielding any results.

            Any ideas how I can read the mass of deleted data that's occupying the filesystem space?

            I also think that there should be a limit to the expansion of the table with deleted data. Like, why would a table of 20MBs in size need 500GB of deleted data in the filesystem?
            marko Marko Mäkelä made changes -
            Status Open [ 1 ] Needs Feedback [ 10501 ]
            danblack Daniel Black made changes -
            ioweb.gr Gabriel Tziotzis made changes -
            Attachment blob.zip [ 72600 ]
            marko Marko Mäkelä made changes -
            Component/s Storage Engine - InnoDB [ 10129 ]
            Component/s N/A [ 14411 ]
            marko Marko Mäkelä made changes -
            Assignee Marko Mäkelä [ marko ]
            marko Marko Mäkelä made changes -
            marko Marko Mäkelä made changes -
            Affects Version/s 10.6.17 [ 29518 ]
            Affects Version/s 10.6.16 [ 29014 ]
            ioweb.gr Gabriel Tziotzis made changes -
            Attachment historylenth.zip [ 73186 ]
            ioweb.gr Gabriel Tziotzis made changes -
            Attachment historylenth-1.zip [ 73201 ]
            marko Marko Mäkelä made changes -
            Assignee Marko Mäkelä [ marko ] Thirunarayanan Balathandayuthapani [ thiru ]
            Status Needs Feedback [ 10501 ] Open [ 1 ]
            marko Marko Mäkelä made changes -
            Status Open [ 1 ] Needs Feedback [ 10501 ]
            marko Marko Mäkelä made changes -
            marko Marko Mäkelä made changes -
            serg Sergei Golubchik made changes -
            serg Sergei Golubchik made changes -
            Status Needs Feedback [ 10501 ] Open [ 1 ]
            ioweb.gr Gabriel Tziotzis made changes -
            Attachment history-list-length.zip [ 73985 ]
            serg Sergei Golubchik made changes -
            Fix Version/s 10.6 [ 24028 ]
            ioweb.gr Gabriel Tziotzis made changes -
            Attachment sample.zip [ 74185 ]
            marko Marko Mäkelä made changes -
            Assignee Thirunarayanan Balathandayuthapani [ thiru ] Marko Mäkelä [ marko ]
            Status Open [ 1 ] Needs Feedback [ 10501 ]
            marko Marko Mäkelä made changes -
            marko Marko Mäkelä made changes -
            Status Needs Feedback [ 10501 ] Open [ 1 ]
            marko Marko Mäkelä made changes -
            Assignee Marko Mäkelä [ marko ] Steve Shaw [ JIRAUSER56063 ]
            Steve Shaw Steve Shaw made changes -
            Assignee Steve Shaw [ JIRAUSER56063 ] Axel Schwenke [ axel ]

            People

              axel Axel Schwenke
              ioweb.gr Gabriel Tziotzis
              Votes:
              1 Vote for this issue
              Watchers:
              8 Start watching this issue

              Dates

                Created:
                Updated:

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