is it problematic to cluster across two datacenters w/aag?

All we need is an easy explanation of the problem, so here it is.

In general is it problematic to cluster across two datacenters that are up to 15-miles apart?

For this one particular project the approach is the following?

  • 2-Node Failover Cluster across two datacenters, one node per datacenter
  • local SAN disks, no shared disks
  • ‘Node and FileShare Majority’ at third location on-campus
  • employ AAG, failover will be manual; asynchronous mode

Is anyone implementing something like this with success??!?

Thanks so much for the help!!

How to solve :

I know you bored from this bug, So we are here to help you! Take a deep breath and look at the explanation of your problem. We have many solutions to this problem, But we recommend you to use the first method because it is tested & true method that will 100% work for you.

Method 1

PASQLDBA it depends really on how much data is being written to the database and the link between these two DC’s and also how far out of sync you can tolerate the two servers keeping your RTO/RPO in mind.

This is by no means any indication of what your milage may be but we have the following setup running quite well.

  • 2 Node Cluster, 1 node in each DC
  • DC’s are a good 20 – 30kms apart
  • Fiber link between the DC’s
  • Local SAN disks
  • Node and File Share Majority
  • Availability Groups setup, auto failover with synchronous commit

This houses multiple AG’s with ~50 databases with no noticeable performance hit over the single instance it was on before.

Hope this helps.

Note: Use and implement method 1 because this method fully tested our system.
Thank you 🙂

All methods was sourced from or, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0

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