Database Mirroring vs Log Shipping. Choose Both?
In a response to my blog entry Database Mirroring and Log Shipping. Which is better? The mysterious Reed Me said:
"Why not do both?
One is HA. One is DR.
It's a no-brainer.
Do both."
I totally agree. In fact, that is exactly what I've been working on for our external customers. Database mirroring will provide high availability inside the datacenter allowing us to forgo clustering and its expensive SAN storage while log shipping will provide DR protection between datacenters.
I would actually rather use asynchronous mirroring between datacenters as failovers are easier to manage, but as noted in my comparison post, you cannot mirror a database more than once. This is why we use log shipping for the "go long" solution. This also just happens to be the same solution that the MS SAP team uses as outlined in their ITShowcase white paper.
One thing to note is that failovers can be complicated to manage when combining mirroring and log shipping. This is because your mirroring principal server is also your log shipping primary server, however, during a mirroring failover your primary role does not automatically follow the principal role. You can either manage this manually like the MS SAP team does or you can automate. If you're like me you don't want to be playing around in SQL after a failover making automation very attractive.
Comments
Anonymous
July 30, 2007
In a previous post , I talked about how I was working on implementing mirroring inside the datacenterAnonymous
July 30, 2007
In a previous post , I talked about how I was working on implementing mirroring inside the datacenter