Hi Steve,

Below is the scenario I want to achieve.

Master  ------------------------------------------------ DR-Master
    |    Replication built on  Slony 2.1.

Given is actually setup of production, master/slave replication with log
archive shipping using slony 2.1. And, Master with DR setup on same data
center as DR-Master with Warm Standby configuration running fine with
minimal lag.

Q: What I want to achieve ?
A:  Swap the Masters. Means, now slave should receive events from DR-Master
once it get promoted to Master as shown below

Master   DR Master

    |            |
   X           |    Replication built on  Slony 2.1.

    |            |

   V            |

Slave <------|

I believed, the DR-Master will have the same _slonyschema except the
primary hostname. So, I have changed on both DR-Master & Slave of sl_path
of primary hostname as fix.
Assuming that, I have tested on my local box with below steps.

1. Stop slony between master,slave.
2. Take the _slonyschema dump of Master (In case any problem).
3. Promote the DR-Master.
4. update the _slonyschem.sl_path of column pa_conninfo with primary
hostname on DR-Master & Slave.
5. Start slony daemons on DR-Master & Slave.

Above steps won't work all the time, I did many times, very few times I
could able to send events from DR-master to Slave with proper numbering of
.SQL files.(log archives).
I would request to recommend the correct procedure for swapping providers.

Blog: htt://raghavt.blogspot.com/
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