No announcement yet.

Master - Slave MySQL Replication - Which dB tables?

  • Filter
  • Time
  • Show
Clear All
new posts

  • Master - Slave MySQL Replication - Which dB tables?


    I searched the vB on-line manual and could not find any references to MySQL master-slave replication.

    We are replicating our vB database and the MySQL configuration is working fine.

    However, normally when you replicate a dB there are some tables that should not be replicated. For example, statistics and site logging tables should not be replicated unless the plan is to have distributed statistics.

    We don't have this plan, and simply want to replicate in a master (read-write) and slave (read-only) configuration.

    As I said, all is working fine, but we could not find any documentation on which tables NOT to replicate.

    Is there a HOWTO document that covers this?


  • #2
    For example, we have already learned that if you replicate your cronjob table (master-slave), your slave will stop replicating because of a duplicate key error. So we had to enter this entry in my.cnf to stop replication of the cronlog:

    replicate-ignore-table = ourvbdb.cronlog
    Of course, another solution would be to configure the slave not to use the cron.

    There must be many of the "gotcha" issues when replicating a vbulletin database, but I have googled my fingers off and cannot find any documentation on this key issues.

    Where is the documentation that discusses all these issues?



    • #3
      Also, if you search the vB 3.8 manual, for example, there is zero the topic of replication (see attachment).

      This is mentioned in config.php, but it simply leaves a hundred more questions than answers:

      // If you have multiple database backends, this is the information for your slave
      // server. If you are not 100% sure you need to fill in this information,
      // do not change any of the values here
      Where is the discussion of MySQL replication? Which tables should not be replicated? Should the vB cron be disabled on the slave? What other vB tasks should be disabled on the slave?

      For those of you who have not implemented a master-slave MySQL configuration, one of the most difficult problems is database inconsistency and duplicate primary key errors. This happens when the slave has updated a table and then the master tries to update the same table, but the primary keys are out of sync (especially in auto-incrementing tables like log files, etc.)

      Where are the details from vB on this?
      Attached Files


      widgetinstance 262 (Related Topics) skipped due to lack of content & hide_module_if_empty option.