Provided by: slony1-doc_1.2.21-1_all bug

NAME

       FAILOVER - Fail a broken replication set over to a backup node

SYNOPSIS

       FAILOVER (options);

DESCRIPTION

       The  FAILOVER command causes the backup node to take over all sets that
       currently originate on the failed node. slonik will contact  all  other
       direct  subscribers  of the failed node to determine which node has the
       highest sync status for each set. If another node  has  a  higher  sync
       status  than  the backup node, the replication will first be redirected
       so that the backup node replicates  against  that  other  node,  before
       assuming the origin role and allowing update activity.

       After  successful failover, all former direct subscribers of the failed
       node become direct subscribers of the backup node. The failed  node  is
       abandoned,  and  can  and should be removed from the configuration with
       SLONIK DROP NODE(7).

       ID = ival
              ID of the failed node

       BACKUP NODE = ival
              Node ID of the node that will take over all sets originating  on
              the failed node

       This uses “schemadocfailednode( integer, integer )” [not available as a
       man page].

EXAMPLE

       FAILOVER (
          ID = 1,
          BACKUP NODE = 2
       );

LOCKING BEHAVIOUR

       Exclusive locks on each replicated table will be taken out on both  the
       new origin node as replication triggers are changed.  If the new origin
       was not completely up to date, and replication data must be drawn  from
       some other node that is more up to date, the new origin will not become
       usable until those updates are complete.

DANGEROUS/UNINTUITIVE BEHAVIOUR

       This command will abandon the status of the failed node.  There  is  no
       possibility  to  let  the  failed  node  join the cluster again without
       rebuilding it from scratch as a slave. If at all  possible,  you  would
       likely  prefer  to  use  SLONIK  MOVE  SET(7) instead, as that does not
       abandon the failed node.

       If there are many nodes in a cluster, and  failover  includes  dropping
       out additional nodes (e.g. when it is necessary to treat all nodes at a
       site including an origin as well  as  subscribers  as  failed),  it  is
       necessary to carefully sequence the actions, as described in “ Failover
       With Complex Node Set ” [not available as a man page].

VERSION INFORMATION

       This command was introduced in Slony-I 1.0

       In version 2.0, the default BACKUP NODE value of 1 was removed,  so  it
       is mandatory to provide a value for this parameter.

                                  12 May 2010               SLONIK FAILOVER(7)