Performance data from SMTP Local Queue Length counter
Topic Last Modified: 2005-11-18
The Microsoft® Exchange Server Analyzer Tool includes a performance data collection engine that is used to query performance counter objects on computers that are running Exchange 2000 Server or Exchange Server 2003. The performance data collection engine collects data from the Local Queue Length performance counter of the SMTP Server performance object to analyze performance data. The Exchange Server Analyzer reports the total number of messages found in the Simple Mail Transfer Protocol (SMTP) local queue.
The SMTP Server\Local Queue Length counter indicates the number of messages in the SMTP queue for local delivery. As a general guideline, the maximum value should be less than 1,000. The queue should remain steady near its average with a small amount of variance.
By default, the Exchange Server Analyzer retrieves a sample every 30 seconds for a two-hour period. The Exchange Server Analyzer reports the maximum value for the performance counter during the collection interval. The Exchange Server Analyzer also reports the value that is at the ninetieth percentile of all collected values.
|If you list in ascending order all the values that the Exchange Server Analyzer collected, the ninetieth percentile is the value at the ninetieth percent position in the list. The ninetieth percentile value indicates the high values of this counter during the collection interval.|
In some instances, the maximum value will be the value at a peak point in the interval. Therefore the maximum value is not representative of the whole interval. The median value does not always accurately indicate load because the median value includes idle time during the collection interval. Therefore, the Exchange Server Analyzer reports the maximum value and the ninetieth percentile value.
A buildup of messages in the Local Delivery queue indicates a performance issue or outages on the server, because the server can no longer deliver the incoming mail in a timely manner. The following conditions can cause this delay:
The Active Directory® directory service is not being consulted promptly.
Messages are not being handed off promptly for local delivery or SMTP.
Databases have been dismounted.
The information in this baseline message is for information purposes only. There is no action required.
For more information about suggested thresholds of performance counters, see Troubleshooting Exchange Server 2003 Performance (http://go.microsoft.com/fwlink/?LinkId=47588).