The holy grail of TM1: the TM1s.cfg file


The TM1s.cfg file is about as close as it gets to the holy grail of your IBM Cognos TM1 server. Strictly speaking only two parameters need to be configured and those are:

  • AdminHost and
  • DataBaseDirectory

These parameters tell what TM1 server to use and where to store the files.

But a quick count learns that in the latest TM1 version (IBM Cognos TM1 10.1.1) there are in total 93 parameters available to configure in the tm1s.cfg file. Many of these parameters can drastically impact the behavior, performance and capabilities of your server. Some of them are not used by default and only in cases where they actually become required. E.g. when you use TM1 in combination with IBM Cognos BI or e.g. when you want to use SSL security. However the majority of the parameters is used, but when not defined by you in the tm1s.cfg file, the default settings are loaded. These default settings are in many cases and environments just fine and do not require changing. But as not a single solution is alike, there are ample opportunities where you just might configure parameters specifically.

So it is absolutely worth it to at least be aware of this and the potential possibilities it brings to optimization and tuning your environment.

TM1s.cfg Parameter Context

The majority of the parameters in the TM1s.cfg file relate to the following topic areas:

  • Configuration and administration
  • Performance
  • Calculation behavior
  • Connectivity
  • Logging
  • End-User capabilities

Especially the performance related parameters are very interesting. The challenge however is that although changing them is really easy, observing in a factual and objective way is not. A closed system in lab conditions that you control completely by yourself is a dream of many.

Each parameter is either required or optional. By default only two parameters are required, it is only when you deviate from a standard setup that more parameters might become required as well, but the majority is optional.

Next to that each parameter is is either dynamic or static. Dynamic simply means that you can change the parameter on the fly while the server is running, the new value will be picked up by the server within 60 seconds after changing it. A static parameter requires you to shut down the server, change or add the parameter and restart the server.

Each version of IBM Cognos TM1 thus far uses a TM1s.cfg file to configure each TM1 server. However, how the TM1s.cfg file looks by default depends a bit on the version of TM1. Below 2 examples, the first is a default TM1s.cfg file from a server running IBM Cognos TM1 version 10.1.1, the second is the default TM1s.cfg file from an IBM Cognos Express version 10.1 server.

View in new window: Default TM1s.cfg file for IBM Cognos TM1 10.1.1 and default TM1s.cfg file for IBM Cognos Express version 10.1 .

TM1s - IBM Cognos TM1 10.1.1 tm1s.cfg

TM1s - IBM Cognos Express 10.1 tm1s.cfg

At the bottom of his article a complete list of all the tm1s.cfg parameters is compiled for your enjoyment … or to stress out about. Either way, the list is compiled as an Excel file for easy browsing. Please note that the content is 99% based on the related IBM material. So how you use it or what you do with it is completely up to you.

For the remainder of this article we will briefly discuss a couple of parameters that might be worth configuring in any more or less default installation. Just to give you an idea what it is about.

Interesting Parameters

Two areas that are always interesting in a TM1 environment, are performance and logging. Below a couple of parameters that are worth looking at.


– The first thing I to do is to change the directory of the log files. By default they are stored in the data directory. If you save them on another location this is more neat and when you would like to perform some manual checks it also reduces the risk that you manipulate by accident another file in the data directory. Parameters:

  • LoggingDirectory
  • RawStoreDirectory

– When you decide to enable logging, you can also play a bit with how fast you can manipulate and consult the data. So if you just need to capture a small set of events, you can play with the how often data is written to the final log files and how often a new file is created. Parameters:

  • AuditLogOn
  • AuditLogMaxFileSize
  • AuditLogMaxTempFileSize 
  • AuditLogUpdateInterval

– Don’t forget that you can also create a server log with the security activity data. Parameters:

  • ServerLogging


– By default TM1 will always check a cube first for standard consolidations and then for rule-based calculations. When you have a large cubes with many consolidations and all consolidations are rule-based, you can skip the check for standard consolidations. Parameter:

  • AllRuleCalcStargateOptimization

– TM1 uses either an ARRAY or TREE method to perform consolidation optimization. ARRAY is used by default and is optimal when you have dimensions with many consolidations and with little sparse data. The TREE method may be more optimal when you have many leaf elements that contain sparse data and little consolidations. One to try out. Parameter:

  • ViewConsolidationOptimizationMethod
  • ViewConsolidationOptimization

– By default TM1 locks subsets when used for other pending requests. You can change this behaviour so TM1 will release locks for other requests. This can work well when many users access the same subset and the subset has many elements. Parameter:

  • SubsetElementBreatherCount

– When you use a 64-bit Windows OS on your server, Windows will perform memory optimization in such a way that memory blocks that are inactive for a long time are paged to disk. In many cases this will generate undesired waiting times for users as user behavior in many TM1 application areas is of a non continuous nature. Parameter:

  • LockPagesInMemory

The Complete Parameter List

This file contains the complete list of all parameters and info that can be configured in the tm1s.cfg file of an IBM Cognos TM1 10.1.1 server. You can download an Excel version here and a *.pdf version here. The file contains the following information about each parameter:

  • Parameter name
  • Dynamic or static
  • Optional or not
  • Default value (if any)
  • Parameter format
  • A short description

All info is based on the official TM1 documentation, however it can still contain some inconsistencies, if you find some, please let us know.

TM1s.cfg parameter list in Excel for IBM Cognos TM1 10.1.1

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