Improving performance of web interviews
To improve the performance of web interviews (particularly startup time), you can configure additional sample management objects.
By default, projects create single sample management objects, and process them sequentially. If you find that this slows down web performance (because, for example, the database server is in a remote location to meet the data residency regulations), you can configure the cluster or individual projects to create multiple sample management objects, and process them simultaneously.
Configuring the entire cluster
In the registry, create an HKLM\SOFTWARE\SPSS\mrInterview\3\SampleManagement key, and then create the following values.
MaxInstances (DWORD)
Specify the maximum number of script programs and corresponding database connections for each sample management.
If an interview requires a sample management operation but the existing script program for that sample management is already executing, new script program is created. This process repeats until the MaxInstance limit of script programs is reached in which case the interview is assigned the least used script program and has to wait until other interviews which have been assigned that script program complete their operations.
The default value is 1.
The minimum value is 1.
CacheTimeout (DWORD)
Specify the timeout in minutes of an unused script program.
Each script program tracks when it was last used to execute a sample management operation. If it has not been used for the duration of the cache timeout, it is removed from memory which also releases its database connection to the sample table.
The default value is 1440 minutes (24 hours).
The minimum value is 1 minute.
Configuring individual projects
In DPM, under \SampleManagements\<SampleManagementName>\Queueing\ Queues\Properties\, set the MaxInstances property to specify the maximum number of instances for the project.
The default value is the value of the MaxInstances property in the registry; if that property is not set, the default value is 1.
See also