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  1. MariaDB MaxScale
  2. MXS-189

FAILOVER and SWITCHOVER admin command to call external script

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    Details

    • Type: New Feature
    • Status: Closed (View Workflow)
    • Priority: Major
    • Resolution: Won't Do
    • Affects Version/s: None
    • Fix Version/s: N/A
    • Component/s: maxadmin
    • Labels:
      None

      Description

      Calling external scripts on monitoring event is a good first step for failover.

      It need additional feature to make the failover a 2 steps procedure:

      • Many users would flavor a 2 step scenario
      • Can be deliver to clients as default setup
      • Removing ownership for failover tricky decision
      • State = dead_master is subject to many false positive.

      First reason to proceed like that is that switchover is most requested feature from users

      • Potentially more frequently triggered when comparing it to hardware failure
      • To upgrade hardware and software
      • For rolling blocking database operations

      Switchover is not control by monitoring but it's a user decision.

      I would suggest that our first monitoring external script just send an email that :

      • Warn the user to double check the reason the master is un-joinable
      • Describe maxadmin command to failover
      • List the current state of all backend
      • Propose the best candidate for failover

      This been done we need to map maxadmin cmd to external scripts

      SWITCHOVER TO <backend_name>
      FAILOVER TO <backend_name>

      Following command pick the best candidate for the command
      AUTO SWITCHOVER
      AUTO FAILOVER

      We need to add options in maxscale config file

      for each backend
      condidate_master=0 means the server can not be elected as potential master

      General section
      cmd_failover_slave_election_script=
      cmd_failover_multi_master_script=

      cmd_switchover_slave_election_script=
      cmd_switchover_multi_master_script =

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              Assignee:
              Unassigned
              Reporter:
              stephane@skysql.com VAROQUI Stephane
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              1 Vote for this issue
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                Dates

                Created:
                Updated:
                Resolved: