What To Install Where? – 7 Considerations
What Do I Install Where – The 7 Considerations
What drives the decision – the answer – to the what goes where question?
The What Goes Where Question
The set of middleware application services installed on any environment is an application cluster. The question is simple – what goes where?
Even on a cloud (like the Amazon EC2 Cloud), you must decide which services to install on which Virtual Machines.
Why Now (To Ask What Goes Where)?
Gone are the days where we had 1 production server. Or the simple – mail server, web server, database server and application server. Today an organisation will depend on up to 10, 20, even 100 middleware services. All this begs the question of what services go where?
The What Goes Where Answer
The answer is also simple. Pick one of the7 considerations – that one that best applies to your situation – and cluster your applications accordingly.
What Packages Do I Install on This Server?
The answer is divided into 8 parts – You can cluster applications in an environment because of
- similar production needs – infrastructure needs like CPU Speed, RAM, RAID needs, Failure Intolerance
- similar admministration needs – the people that maintain the services (engineers and administrators)
- similar consumption needs – a cluster of apps needing a data warehouse, or responding to similar events
- similar purpose – like enterprise integration – queue processors, web Services Endpoints, XML messaging
- similar producers – those that create like software developers, architects
- similar consumers – services consumed by “business users” or “project administrators”
- similar security requirements – what do objects in a bank safe have in common, objects in a safe at home, people in the green zone in Baghdad (why are all those people in the one place instead of being scattered around the city?).
- similar interactions – think about messaging, queues, communications and relationships
Why Build a Factory Here?
Think of building a factory. Why build the factory right here? Why not over there?
– the land is flat – its near the sea,
– skilled personnel are available here – as opposed to there
– a big freshwater lake that is vital, port access for exporting our products
– our supply chain is located nearby
– our consumers are nearby
The question Why Cluster these Apps In This (Instead of That) Environment boils down to which of the 7 categories you feel best suits your needs. You can never be 100% correct. And things will change with time.
You cannot have a right first time solution to this problem. What you can have though, is a good starting point.