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  1. MariaDB MaxScale
  2. MXS-969

use_sql_variables_in=master can break functionality of important session variables

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    Details

    • Type: Bug
    • Status: Closed (View Workflow)
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: 2.0.1
    • Fix Version/s: 2.0.2
    • Component/s: readwritesplit
    • Labels:
      None
    • Sprint:
      2016-22

      Description

      When use_sql_variables_in=master, the ReadWriteSplit router will route queries like the following only to the master:

      SET SESSION wsrep_sync_wait=1;
      

      In this specific case, it's very important that wsrep_sync_wait get set on the slaves. If the variable is only routed to the master, the application might see errors when queries don't return the expected results.

      https://mariadb.com/kb/en/mariadb/galera-cluster-system-variables/#wsrep_sync_wait

      Possible fixes:

      • Only let use_sql_variables_in affect user-defined variables, not system variables.
      • Only let use_sql_variables_in affect queries that read variables, not queries that write variables with SET.

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            Assignee:
            markus makela markus makela
            Reporter:
            GeoffMontee Geoff Montee
            Votes:
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              Updated:
              Resolved:

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