If you choose Interview Engine as the Performance object, you have access to the following performance counters. If you have more than one instance of Interview Engine registered, you might want to monitor each instance separately.

The “per second” and “average time” values that are displayed in Performance Monitor (perfmon) are calculated by Performance Monitor every time that it updates:

Number of active threads.

Similar to the Interviewer Web Service performance object's Active Threads counter. This is the total number of threads that handle web requests. Web requests are queued upon arrival. If a thread is available in the thread pool in the Interviewer Server Web Service, a request is removed from the queue and the available thread starts handling the request. At this time, the counter value increases by 1. After the request is handled, the counter value decreases by 1.

Average time spent handling a request.

Similar to the Interviewer Web Service performance object's Average Response Time counter. The Interviewer Session Engine records the total time spent handling all requests and the total number of handled requests. The counter value is the result of the total handling time divided by the total number of handled requests.

Number of interviews completed or stopped by the Stop button per second (includes Web and Telephone interviews).

Number of interviews currently running.

The counter value increases by 1 when an interview starts or restarts, and decreases by 1 when an interview completes or times out.

Number of interviewers.

The counter value increases by 1 when the session engine creates a session for an interviewer, and decreases by 1 when the session engine closes an interviewer session.

Number of requests currently queued for processing.

Similar to the Interviewer Web Service performance object's Current Queued Requests counter. When a request arrives, the counter value increases by 1. After a thread starts handling a request, the counter value decreases by 1.

Number of supervisors who are monitoring.

The counter value increases by 1 when the session engine creates a supervisor session, and decreases by 1 when the session engine closes a supervisor session.

Number of errors generated per second.

Errors are exceptions that occur when the session engine creates a web or telephone interview, or when processing the interview's post event.

The number of cache subscriptions that failed to transfer to the database (per second).

Monitors the number of job steps that are currently queued.

Maximum time spent handling a request.

The counter uses the same data as the Average Response Time counter.

Number of page requests per second.

The number of page requests increases by 1 when the session engine returns a interview page as player XML. This happens after the session engine finishes creating a web or telephone interview, or when processing the interview's post event.

Current value of PercentLoaded (used for load balancing).

The counter value is the PercentLoaded value returned by the session engine's load balancing script. The value is updated each time the load balancing script is called. See Load balancing interviewing engines for more information.

Number of files awaiting a retry at transferring them from the Value Cache to the case data. See Value Cache for more information.

Number of files awaiting transfer from the Value Cache to the case data.

Number of interviews restarted per second. This counter only includes the number of restarts after timeout (restarts via the cache file), not restarts via sample management.

Number of requests that could not be sent to the server.

Similar to the Interviewer Web Service performance object's Server Failed Requests counter. When an error occurs during the web server’s request handling, the counter value increases by 1. In this case, the HTTP status code is typically greater than or equal to 400.

Number of requests sent to the server per second.

Number of requests sent to the server altogether. The total number of the handled requests, including the successful and failed requests.

Number of interviews started per second. This counter includes interviews being started for the first time and interviews being restarted from sample management. It does not include restarts after timeout.

Number of interview time-outs per second.

The total number of cache files that reside in the primary and secondary cache folders.

The counter value is updated after the Transfer Service scans the primary and secondary cache folders, and represents the total number of cache files (*.chj) in the folders at the time of the scan. Given that the scan occurs at different times for each interviewing engine, this counter is expected to be inconsistent across the different engines.

The primary cache folder is typically the only folder, and has a DPM site property value ofInterviewCacheUNC. The Transfer Service hosted in every session engine scans the same cache folder, resulting in the Total Cache Files counters for all engines displaying the same value. An Interview Session Engine’s counter can be monitored to track the total number of cache files residing in the cache folder.

The cache files in the cache folder may not all qualify to transfer to the database. Monitor the Queued Transfers counter to obtain the number of cache files that are ready to transfer. See Value Cache for more information.

Total number of interviews completed or stopped since the engine started (includes Web and Telephone interviews).

The total number of cache subscriptions that failed to transfer to the database.

Total number of interviews that have been started since the engine was started, including restarts due to timeout\shutdown or starts on other engines due to failover.

The total number of interviews restarted since the engine started. This olny includes restarts due to timeouts\shutdowns; it does not include failovers.

Total number of interview time-outs since the engine started.

Total number of files transferred from the Value Cache to the case data.

Number of cache files transferred per second from the Value Cache to the case data.