F5 to load balance MS Sql Servers

Chenna,

 

 

While load balancing SQL servers does in fact work, and we have customers who have implemented it, it's important to uderstand some of the challenges associated with SQL LBing.

 

 

One of the most challenging aspects of load balancing SQL servers is managing reads vs. writes, and making sure the changes get replicated amongst the SQL servers fast enough. If a 'user' is load balanced to one server and makes a record write, the SQL synchronization technology you are using (most likely log shipping or mirroring), must be able to replicate that change to the other SQL servers before the next 'user' requests that data, as they may have been sent to a different SQL server in the farm.

 

 

More often than not, when I hear that the BIG-IP is being used to load balance a SQL farm, the farm is either built of read-only servers, or the BIG-IP is actually being used to 'load balance' active-passive SQL clusters.

 

 

I'm not sure what your specific requirements are for this deployment, however I thinks its important to weigh the benefits and drawbacks of clustering vs. load balancing in this case. With SQL, a lot of times clustering is the technology that makes sense.

 

 

-Ryan