DTM is an abbreviation for Data Transformation Model. It identifies the area of memory where a mapping and its metadata are loaded. Normally, once the mapping has finished, this memory is discarded. In the case of web services, you can instruct your Informatica installation not to destroy this memory and make it available if another request is received.

The DTM Keep Alive Time value defines how long to keep the DTM running after it has dealt with a request. Configure the keep alive time as high as the available resources permit.

When a web service request is received and no DTM is available, Data Quality initializes a new DTM to deal with the request. The initialization process may mean loading reference tables, address reference data, or probabilistic models into memory. The process may take seconds to complete and considerably increase the response time. If all the above are preloaded to the DTM, the response time will be milliseconds as opposed to seconds.

You can configure the DTM Keep Alive Time value as a Data Integration Service property in the Administrator tool.

The following image shows the DTM Keep Alive Time property on the Data Integration Service:

You can also set a web service-specific keep alive time. This value takes priority over the value set on the Data Integration Service. To set the value, browse to the web service under the Applications tab of the Data Integration Service in the Administrator tool.

The following image shows the DTM Keep Alive Time property on the web service:

The Maximum Execution Pool Size property defines the maximum number of mappings that can run concurrently in the Data Integration Service. The larger the number, the more resources the Data Integration Service will require.

The Max Concurrent Requests property defines the maximum number of concurrent HTTP or HTTPS requests that the Data Integration Service process can accept. The larger the number, the more resources the Data Integration Service will require.

The Max Backlog Requests property defines the maximum number of HTTP or HTTPS requests that can reside on the queue for the Data Integration Service process before the requests are rejected.