Subject RE: [firebird-support] Database Replication / Shadowing
Author Alan McDonald
> We are currently looking at co-locating one of our servers with our ISP,
> our primary server will stay at our location - the problem we are
> facing is one of data synchronization between the two.
> Our main server runs FB1.5.1 and JayBird 1.5.3.
> What we are looking for is some way of (in real time) replicating the
> data to the secondary server located at the ISP.
> My question is this: With FB and database shadowing, is the access to
> the shadow database queued and run in the background or does the fb
> server block until all of the read/writing is completed. This is an
> issue as the ISP is over a 512k RF link and the database experiences
> high load bursty traffic.

the shadow is not a useable database. Nor is it possible to shadow to a
non-system drive.

> A google brought up products such as IBReplicator, we would like to have
> the database mirrored in real time however - not scheduled for
> replication every x hours.

you can replicate on event triggers - not timing schedules if you wish. Not
sure about IBReplicator but FBReplicator has this option. Or you can
replicate every 60 seconds if you wish. You are still subject to the overall
quantities of data to be replicated (ie. it could take more than 60 secs to
replicate the results of large updates).

> Are there any other techniques / applications for mirroring/replication
> of the database out there, especially if one of the db's is over a slow
> link?

You can replicate over slow links - it just takes longer :-) I don;t know of
ways to replicate 50Mb in 2 seconds no matter what the system

> Regards,
> Ryan Thomas
> TransActive Systems