Method 1: Connect back to original instance of interview
To enable this feature, set the DPM properties that are described in this section.
You can set default values for the properties at the DPM site level. You can then change these values for individual projects under the project’s "mrInterview" collection.
For information about how to set the properties by using DPM Explorer, see
DPM Explorer.
Also check that the IsCachedInterview property is referenced in your load balancing script to ensure that existing interviews are load balanced to their original engine. For more information, see
Default UNICOM Intelligence Interviewer load balancing script.
DPM properties
OnStartCheckForExistingInterview
True checks for existing running interviews using the same sample information when a respondent starts a new interview. If an interview already exists using that sample information, the last visited page of that interview is displayed instead of starting a new interview.
The sample management Authenticate function is skipped avoiding the requirement to wait for the original interview to timeout before restarting the interview.
OnStartMatchSampleFields
If your start URLs contain extra sample fields which are not used in sample authentication and might change between interview starts (for example, IPAddress, use this property to specify which sample fields are to be used for the existing interview check, for example:
ID, Password
If this parameter is not set, all sample fields in the start URL are used to match existing interviews.
OnStartMatchSampleValues
Controls which value for the sample field is used when matching to an existing interview.
0: Use the sample field values as returned from Sample Management AuthenticateSampleRec. This enables the “check for existing interview” feature to be used with projects that have an option to add new sample records. For example, if an ID value of blank or _ADDNEW indicates that a new sample record should be added, the value of ID post-authentication will be the newly generated ID. By keying the interview cache on the generated ID, this avoids all _ADDNEW interviews being connected to the same interview instance.
1: Use the sample field values that are specified on the start URL. Use this value when the URL parameters uniquely identify the respondent, but AuthenticateSampleRec modifies the sample field values.
The default value is 0.
Example 1
The start URL includes only the authentication sample fields, for example:
http://localhost/mrIWeb/mrIWeb.dll?I.Project=MM1&ID=MyID&Password=MyPassword
Use:
OnStartCheckForExistingInterview = True
Example 2
The start URL includes fields passed through the sample management script that are not used for authentication, but might be stored or used by the interview. These URLs are typically generated automatically and might contain information that is different on each attempt.
Use:
OnStartCheckForExistingInterview = True
OnStartMatchSampleFields = ID,Password
Example 3
The start URL includes sample fields that are passed through the sample management script and changed in the process. The matching should occur on the fields after the authentication function completes.
This includes examples like the addrecord_sample.mrs that allow URLs like:
http://localhost/mrIWeb/mrIWeb.dll?I.Project=MM1&ID=AddNew
In this case, the ID is automatically generated by the sample management script so is only valid after the authentication completes.
Use:
OnStartCheckForExistingInterview = True
OnStartMatchSampleFields = ID
OnStartMatchSampleValues = 0 (default)
Example 4
The start URL includes sample fields that are passed through the sample management script and changed in the process, but the matching should occur on the fields before the authentication function completes.
In this case, the matching check uses the sample fields before authentication.
Use:
OnStartCheckForExistingInterview = True
OnStartMatchSampleFields = ID
OnStartMatchSampleValues = 1
See also