func updateReplicationGraphForPromotedSlave(ts topo.Server, tablet *topo.TabletInfo) error {
// Remove tablet from the replication graph if this is not already the master.
if tablet.Parent.Uid != topo.NO_TABLET {
if err := topo.DeleteTabletReplicationData(ts, tablet.Tablet); err != nil && err != topo.ErrNoNode {
return err
}
}
// Update tablet regardless - trend towards consistency.
tablet.State = topo.STATE_READ_WRITE
tablet.Type = topo.TYPE_MASTER
tablet.Parent.Cell = ""
tablet.Parent.Uid = topo.NO_TABLET
tablet.Health = nil
err := topo.UpdateTablet(ts, tablet)
if err != nil {
return err
}
// NOTE(msolomon) A serving graph update is required, but in
// order for the shard to be consistent the old master must be
// scrapped first. That is externally coordinated by the
// wrangler reparent action.
// Insert the new tablet location in the replication graph now that
// we've updated the tablet.
err = topo.CreateTabletReplicationData(ts, tablet.Tablet)
if err != nil && err != topo.ErrNodeExists {
return err
}
return nil
}
// updateReplicationGraphForPromotedSlave makes sure the newly promoted slave
// is correctly represented in the replication graph
func (agent *ActionAgent) updateReplicationGraphForPromotedSlave(ctx context.Context, tablet *topo.TabletInfo) error {
// Update tablet regardless - trend towards consistency.
tablet.Type = topo.TYPE_MASTER
tablet.Health = nil
err := topo.UpdateTablet(ctx, agent.TopoServer, tablet)
if err != nil {
return err
}
// NOTE(msolomon) A serving graph update is required, but in
// order for the shard to be consistent the old master must be
// scrapped first. That is externally coordinated by the
// wrangler reparent action.
// Insert the new tablet location in the replication graph now that
// we've updated the tablet.
err = topo.UpdateTabletReplicationData(ctx, agent.TopoServer, tablet.Tablet)
if err != nil && err != topo.ErrNodeExists {
return err
}
return nil
}