Aaron Randall wrote:

>For example, does Slony use two-phase commit/have a set Master buffer 
>size/a recommended minimum delay time for Slony to work successfully?
>  
>
There is no two phase commit involved...

Slony-I is an *asynchronous* replication system, meaning that changes
are recorded at the origin, and then applied to the subscribers some
time later.  "Some time later" can be fairly arbitrarily later.

We're running Slony-I across some across-the-continent links, which
doesn't require any kind of special Slony-I configuration.  Slony-I
doesn't use any special network protocol; it merely connects as Yet
Another PostgreSQL client via libpq and the concommittant network
protocol used by psql and other "ordinary" PostgreSQL clients.

High bandwidth across that distance is pretty expensive, so there is
likely to be the compromise that you've got limited bandwidth.  That
will make it take a long time to get a new subscriber set up across the
WAN link.  But once it is subscribed, we commonly see that the "very
distant" node is only a second or two behind.

There is an indirect notion of "buffer size" in terms of the "sync
grouping" (the -g parameter to slon); in version 1.2, there will be a
buffer size used to manage MEMORY consumption.  But that's all more
about memory management than network management.