Looking for performance improvement in IBM Cognos TM1?  IBM added a new configuration in TM1 9.5.2 to improve write performance called Parallel Interaction in TM1.

What does Parallel Interaction in TM1 do?

Parallel Interaction is a server configuration that improves writer response times by removing lock contention resulting from concurrent cube data access (readers or writers). When enabled, Parallel Interaction changes the TM1 Object Locking model so that write operations are not blocked by concurrent data read or data write operations to the same cube (or dependent cubes based on rules). Read operations will always include the most current write activity as of the time the read operation begins.

When Parallel Interaction is turned on, performance can be improved.  But note the default is that Parallel Interaction is turned off.  So you will need to modify the config file.

How to turn on Parallel Interaction in TM1 9.5.2?

To turn on Parallel Interaction in 9.5.2 (not available in earlier releases), which by default is off, modify the server configuration tm1s.cfg file by adding:
ParallelInteraction=T
You will need to restart the server after changing the setting for it to be activated.
*Note: IBM changed the name of this feature so watch out some of the documentation may be incorrect.

When to use Parallel Interaction:
IBM recommends using Parallel Interaction for any TM1 application involving writeback activity. Realizing the benefit of Parallel Interaction is dependent upon having sufficient server CPU cores to process the greater throughput of concurrent read and write operations and ensuring that any remaining ‘blocking’ activity resulting from meta data maintenance does not interfere with writer performance.

Turn on Parallel Interaction if you are looking for immediate writer response times under the following situations:
• Support concurrent writers executing high level data spreading input
• Support high user counts for readers demanding instantaneous access to freshly entered data
• Keep TM1 environments ‘fresh’ with Intra-Day cube data loads
• Execute Turbo Integrator Data Allocation Processes sourcing data from Input Cubes
• Execute Turbo Integrator Data Manipulation Processes to incrementally build Reader Cubes sourcing data from Input Cubes

When to NOT to use Parallel Interaction:
1. Read Only Applications:
Parallel Interaction does not improve query performance, so therefore is not recommended for TM1 read-only applications.

2. Deficient CPU:
Customers will observe significantly higher CPU utilization when using TM1 9.5.2 Parallel Interaction during periods of high read/write concurrency as compared to previous versions of TM1. Insufficient TM1 server core capacity may negatively impact the potential performance advantages of Parallel Interaction. TM1 customers upgrading to TM1 9.5.2 from prior versions are advised to monitor TM1 server CPU utilization when operating with Parallel Interaction to ensure that server cores are not ‘saturated’ – evident by > 80% server utilization for moderate to long periods of time.

If use of TM1 9.5.2 PI is resulting in TM1 Server core ‘saturation’, IBM recommends customers add additional cores to the server as available or consider a server with more available cores.