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  1. MariaDB Server
  2. MDEV-6242

Some but not all slaves do character set mangling

        Details

        • Type: Bug
        • Status: Closed
        • Priority: Major
        • Resolution: Duplicate
        • Affects Version/s: 10.0.10
        • Fix Version/s: 10.0.11
        • Component/s: None
        • Labels:
          None
        • Environment:
          Linux,RHEL6

          Description

          Setup: dual master (probably not relevant), N slaves, everything MariaDB 10.0.10
          All servers essentially the same config (copies from same source with only server specifics changed)
          Binlog format MIXED
          InnoDB engine
          Parallel replication enabled
          All charset settings utf8

          Table/column utf8.

          utf8 string inserted on active master, reads back ok.
          On other master (acting as slave), incorrect (charset mangling)
          On some slaves, OK
          On other slaves, incorrect

          Which slaves get a string incorrect changes per row, so it's not always the same ones.

          Interesting isn't it?

          Verified by doing SELECT SHA1() on the affect column, to rule out any client mangling.

          SELECT string, SHA1(string) FROM t\G

          Correct:

          string: Atlético Madrid
          SHA1(string): 6dec52f694515702664a20b7660574139267a46a

          Incorrect:

          string: Atlético Madrid
          SHA1(string): db4bb2aa6aae25ce19e0dda3626d37fa356c673e

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                duplicates

                Bug - A problem which impairs or prevents the functions of the product. MDEV-6156 Parallel replication incorrectly caches charset between worker threads

                • Major - Major loss of function.
                • Closed

                  Activity

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                  arjen Arjen Lentz added a comment -

                  I realise that because of the setup this one might be tricky to reproduce.
                  At this point I'm particularly interested in possible ideas on how this issue could occur, as that might also help me devise a setup to reproduce the issue in an isolated environment.

                  Show
                  arjen Arjen Lentz added a comment - I realise that because of the setup this one might be tricky to reproduce. At this point I'm particularly interested in possible ideas on how this issue could occur, as that might also help me devise a setup to reproduce the issue in an isolated environment.
                  Hide
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                  arjen Arjen Lentz added a comment -

                  knielsen (IRC) reckons it could be a case of https://mariadb.atlassian.net/browse/MDEV-6156

                  I'll upgrade a few of the slaves to 10.0.11 to see.

                  Show
                  arjen Arjen Lentz added a comment - knielsen (IRC) reckons it could be a case of https://mariadb.atlassian.net/browse/MDEV-6156 I'll upgrade a few of the slaves to 10.0.11 to see.
                  Hide
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                  arjen Arjen Lentz added a comment -

                  Provisionally, the upgrade to 10.0.11 appears to have resolved the issue - no new discrepancies have been spotted since the upgrade. We'll keep an eye on it just to be sure.
                  So, I'll mark this issue as a dup of MDEV-6156 as it appears to have been the same bug.

                  thanks for your quick assistance, Kristian!

                  Show
                  arjen Arjen Lentz added a comment - Provisionally, the upgrade to 10.0.11 appears to have resolved the issue - no new discrepancies have been spotted since the upgrade. We'll keep an eye on it just to be sure. So, I'll mark this issue as a dup of MDEV-6156 as it appears to have been the same bug. thanks for your quick assistance, Kristian!

                    People

                    • Assignee:
                      knielsen Kristian Nielsen
                      Reporter:
                      arjen Arjen Lentz
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                      Dates

                      • Created:
                        Updated:
                        Resolved: