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    Add node back into galera cluster (brute force)

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    • adminA
      admin
      last edited by admin

      Here is the scenario...

      You have a 3 node galera (g1,g2,g3) cluster and there is some network maintenance which stops connectivity between the nodes causing them to lose their quorum and stop serving.

      To fix this you disable 2 nodes (g2,g3) and bring just one back (g1)...

      you should be able to bring the 1 node back with the following command:
      galera_new_cluster
      If that causes a failure, you may also need to update a line in your /var/lib/mysql/grastate.dat file.
      to do this change:
      safe_to_bootstrap: 0
      to
      safe_to_bootstrap: 1
      now run the galera_new_cluster command again and it "should" work...

      Once your network settles down and connectivity is regained you will have 2 galera nodes which will no longer gracefully start up, what do you do?

      Feel free to use the following hammer:

      On g2

      cd /var/lib/mysql
      rm grastate.dat
      rm ib_logfile*
      sudo -u mysql mysqld --wsrep_sst_donor=g1
      

      where "g1" is the wsrep_node_name of your working/primary galera node

      follow the above instructions for g3 and you should be all set...

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