Re: Moving Towards Slony-I 1.1

On Mar 11, 2005, at 11:03 AM, Jan Wieck wrote:

> We have recently discovered that MOVE_SET has a race condition. If for 
> example one has nodes 1, 2 and 3. 1 being origin, 2 and 3 being 
> subscribers. If one now does a MOVE_SET to transfer the origin to node 
> 2 there is a possibility that node 2 processes that MOVE_SET, opens up 
> for business and generates SYNC's (so far this is what we want).
>

Is there a possibility that a similar race exists for when you move a 
node's origin?

When I brought on a new server, I had done it where origin node 2 fed 
replica node 1 which fed replica node 3:

2 -> 1 -> 3

then I moved it so 3 fed right from 2:

2 -> 1
2 -> 3

I waited a while to make sure all replicas were "up to date" (ie, no 
events backlogged according to sl_status).  Then I went to remove node 
1, and it seems that it all stopped since the listen paths were 
reconfigured in seemingly the wrong order (ie, old listens removed 
before new listens were added).

This is when I had to go into the event table on the origin and remove