Global Server Load Balancing

Now we also have Global Server Load Balancing (GSLB). This is not a high availability feature per say; however, as the name describes, it is a load balancing feature.

GSLB works with the help of DNS. It allows us to deliver a service from different data centers spread across different geographical locations; this helps us in case of data center failures and disaster recovery.

It can also help to spread the load across different locations with its proximity feature, and allows users to be sent to the closest data center. This type of feature is already in use today is many large web services such as Google, Facebook and so on.

So, let's take a closer look at how GSLB works. First off, it is important to know how DNS functions, as this is the fundamental component in GSLB.

When a user connects to a service, for example, www.myservice.company.com, the client will send a DNS request to its DNS server, which is the NS server. The DNS server of the client will send a recursive...