SLONIK MOVE SET(7) Configuration and Action commands SLONIK MOVE SET(7)NAME
MOVE SET - Change origin of a Slony-I replication set
SYNOPSIS
MOVE SET (options);
DESCRIPTION
Changes the origin of a set from one node to another. The new origin
must be a current subscriber of the set. The set must currently be
locked on the old origin.
After this command, the set cannot be unlocked on the old origin any
more. The old origin will continue as a forwarding subscriber of the
set and the subscription chain from the old origin to the new origin
will be reversed, hop by hop. As soon as the new origin has finished
processing the event (that includes any outstanding sync events that
happened before, i.e. fully catching up), the new origin will take over
and open all tables in the set for client application update activity.
This is not failover, as it requires a functioning old origin node (you
needed to lock the set on the old origin). You would probably prefer
to MOVE SET instead of FAILOVER, if at all possible, as FAILOVER winds
up discarding the old origin node as being corrupted. Before MOVE SET
will function a LOCK SET is needed.
Note that this is a locking operation, which means that it can get
stuck behind other database activity.
ID = ival
ID of the set to transfer
OLD ORIGIN = ival
Node ID of the current set origin
NEW ORIGIN = ival
Node ID of the new set origin
This uses moveset(integer,integer).
EXAMPLE
LOCK SET (
ID = 1,
ORIGIN = 1
);
MOVE SET (
ID = 1,
OLD ORIGIN = 1,
NEW ORIGIN = 3
);
LOCKING BEHAVIOUR
Exclusive locks on each replicated table will be taken out on both the
old origin node and the new origin node, as replication triggers are
changed on both nodes: on the former origin, each table has two trig‐
gers (logtrigger and lockset) dropped and a denyaccess trigger added;
on the new origin, the denyaccess trigger is dropped and a logtrigger
trigger added.
SLONIK EVENT CONFIRMATION BEHAVIOUR
Slonik waits for the command submitted to the previous event node to be
confirmed on the specified event node before submitting this command.
VERSION INFORMATION
This command was introduced in Slony-I 1.0
18 January 2015 SLONIK MOVE SET(7)
