Not everyone understands what a cluster is. It’s when you have 2 or more servers running your website. Something like this:
Your WordPress website would run across all the servers in the cluster.
A cluster is used for 2 mains reasons – for increased performance and increased reliability.
Usually if you want your WordPress website to go faster you try this like : a faster server, more caching, tuning, bigger server. But all these are slow and time consuming. Upgrading the server to a larger one can be disruptive.
Once you have a cluster adding an additional server is easy, quick to do and non-distruptive.
By adding another server to the cluster the faster the response for your users. The more servers the faster your WordPress website goes.
You can add extra servers for a special event you might be having, like a marketing campaign. You can also build clusters that are auto-sizing.
If any of the servers in the cluster stop working, they are removed from the cluster, but your WordPress website keeps working.
If you have a single server you’re basically waiting until it breaks, one day, then you have an emergency to deal with.
If you need to upgrade software, or upgrade the operating system, you can remove the server from the cluster first. Then you can upgrade it, and test it, before re-adding to the cluster. The end users won’t even know your doing maintenance. This gets you much closer to 100%.
At WPdone our cluster is also across multiple data centre’s and across multiple vendors.
So if any particular data centre has an issue, or a DDoS, your WordPress website can continue to run on the surviving data centre.
Without a cluster for your hosting – you have the ol’ problem of relying on 1 server, 1 internet, 1 database.
At WPdone we cluster each component. So we have multiple servers, for each component of your website.
We also cluster the load balancing servers.
And we use smart routing from each client, so it can find multiple load balancers to locate the databases and memory cache.