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  1. MariaDB Server
  2. MDEV-6206

wsrep_slave_threads subtracts from max_connections

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    Description

      my.cnf:

      max_connections=200
      		 
      wsrep_slave_threads=400
      		 

      # /etc/init.d/mysql restart ;  mysql -u openquery 
       * Stopping MariaDB database server mysqld                                                                                          [ OK ] 
       * Starting MariaDB database server mysqld                                                                                          [ OK ] 
       * Checking for corrupt, not cleanly closed and upgrade needing tables.
      		 
      ERROR 1040 (HY000): Too many connections
      		 
      # ERROR 1040 (HY000): Too many connections

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          elenst Elena Stepanova added a comment -

          I'm not sure it's actually wrong, assigning to nirbhay_c to decide.

          elenst Elena Stepanova added a comment - I'm not sure it's actually wrong, assigning to nirbhay_c to decide.
          danblack Daniel Black added a comment -

          My basis for the bug report is the max_connections definition:

          https://mariadb.com/kb/en/server-system-variables/#max_connections
          max_connections Description: The maximum number of simultaneous client connections

          Though a wsrep_slave_threads shows up in the process list its not actually a client connection.

          I see the wsrep_slave_threads also affects the status threads_connected.

          Variable_name Value
          Threads_connected 66

          I appreciate that even async replication took two "connections" as a slave and 1 per slave as a master however it seems wsrep_slave_threads can make much more of an impact into the max_connections.

          I'm in favour of preserving the definition of max_connections as client connections but alter the statusThreads_connected definition to include systems threads.

          danblack Daniel Black added a comment - My basis for the bug report is the max_connections definition: https://mariadb.com/kb/en/server-system-variables/#max_connections max_connections Description: The maximum number of simultaneous client connections Though a wsrep_slave_threads shows up in the process list its not actually a client connection. I see the wsrep_slave_threads also affects the status threads_connected. Variable_name Value Threads_connected 66 I appreciate that even async replication took two "connections" as a slave and 1 per slave as a master however it seems wsrep_slave_threads can make much more of an impact into the max_connections. I'm in favour of preserving the definition of max_connections as client connections but alter the statusThreads_connected definition to include systems threads.
          nirbhay_c Nirbhay Choubey (Inactive) added a comment -

          Hi Daniel,
          I too think "system" threads should not be included under "connection" threads. However,
          I do not feel like changing the definition of Threads_connected, would rather introduce a
          new status variable representing wsrep thread count. Thanks!

          nirbhay_c Nirbhay Choubey (Inactive) added a comment - Hi Daniel, I too think "system" threads should not be included under "connection" threads. However, I do not feel like changing the definition of Threads_connected, would rather introduce a new status variable representing wsrep thread count. Thanks!
          danblack Daniel Black added a comment -

          > I too think "system" threads should not be included under "connection" threads.

          Thank you. I hoped you see it that way too.

          > However,I do not feel like changing the definition of Threads_connected, would rather introduce a
          new status variable representing wsrep thread count.

          works for me.

          danblack Daniel Black added a comment - > I too think "system" threads should not be included under "connection" threads. Thank you. I hoped you see it that way too. > However,I do not feel like changing the definition of Threads_connected, would rather introduce a new status variable representing wsrep thread count. works for me.
          nirbhay_c Nirbhay Choubey (Inactive) added a comment -

          Fix pushed to maria-5.5-galera.

          nirbhay_c Nirbhay Choubey (Inactive) added a comment - Fix pushed to maria-5.5-galera.
          danblack Daniel Black added a comment -

          thank you.

          http://bazaar.launchpad.net/~maria-captains/maria/maria-5.5-galera/revision/3492

          danblack Daniel Black added a comment - thank you. http://bazaar.launchpad.net/~maria-captains/maria/maria-5.5-galera/revision/3492

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            nirbhay_c Nirbhay Choubey (Inactive)
            danblack Daniel Black
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              Resolved:

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