I have the need to replicate the transactions from 4 independent servers.
Each server logs transactions and needs to lookup the transaction history of
each of the other 3 servers.  I have two servers each in 2 data centers.
The reason for having 4 servers is that in the event of a problem we can
lose a server or a data center and the others can continue processing.  The
total volume of transactions across all 4 servers is less than 2 thousand
per minute.

I'm thinking of using service broker to replicate the transactions to each
of the other 3 servers.  I can live with a 5 second latency and expect it to
be much less.  I feel a simple SB application would do the replication and
gives me more flexibility in terms of recovery when things go wrong.  The
alternative is a 4 way merge replication of a table.  My biggest concern
with replication is recovery when things go wrong, and controlling the error
handling during maintenance reboots of individual servers.

One of the appealing aspects of rolling my own replication application using
service broker is that I can build a new copy from the most recent date
backwards.  The table will have a 90 day history of transactions, but 95% of
the activity will be looking at the most recent 48 hours.  So in building a
new server it can be operational after restoring just the most recent 2
days.  I don't believe I would have this flexibility using replication.  I
could start processing on the new server while the history is backfilled.

Having said all that, both of these are new technologies to me so I'm open
to hearing what people think.

Regards, JP