TM1 Forum

I have been searching the forum and have had no luck finding an answer to my question. I guess this must have been discussed before so bear with me (or please give me a link).

We are running TM1 10.2.2 FP2 at the moment with one TM1 server instance (production environment) and we are not quite sure what road to follow going forward. We have a requirement where we will need to implement a new model which is very much like one we already have but there are some distinct differences (data sources/processes, key dimensions are not the same, data flows between cubes are not the same, ...).

It is very tempting to create a new TM1 server instance with a copy of the existing model and then modify it. That would be much more easy compared to building the model on the existing server.

What are the pros and cons of having one or multiple TM1 server instances (in the production environment)?

Having multiple models in one TM1 server instance
Pros:
Dimension reuse
Security groups can be reused
Optimal use of server resources (cores, memory)?

Cons:
Difficult to clone models
Server instance cannot be restarted without affecting other TM1 models


Having multiple TM1 server instances with only one model (or few models)
Pros:
Models with common features can easily be copied to new server instance and be modified there
Restart of server without affecting other models

Cons:
Need to maintain a number of dimensions in more than one place
Server resource overhead (memory, CPU)?


Or course "it depends" - but what would you recommend as a general best practice and why?

Thank you in advance.

This is a good question. I'm sure it would have been asked here before and has certainly been discussed during many projects.

Firstly DO check your licensing. There are still many licensing variants which have a per instance charge as well as a per user charge. The newest ones are based on user count only and don't limit the number of instances but you don't want to fall foul of an IBM audit.

To keep my answer short and to the point I would advise to keep the new application on the same tm1 instance unless you have a really compelling reason not to, say the user community of each application is completely non-overlapping or you have memory or disk resource constraints necessitating separate hardware or severe performance issues.

If metadata is shared and should be consistent it is going to be much less ongoing maintenance to have a single instance.