Exchange Availability Service Test

The Microsoft Exchange server 2007/2010 Availability service improves information workers' calendaring and meeting scheduling experience by providing secure, consistent, and up-to-date free and busy information to computers running Microsoft Office Outlook 2007. Outlook 2007 uses the Autodiscover service to obtain the URL of the Availability service. The Autodiscover service is similar to the Domain Name System (DNS) Web service for Exchange 2007/2010 Web services. Essentially, the Autodiscover service helps Outlook 2007 locate various Web services, such as the Unified Messaging (UM), Offline Address Book (OAB), and Availability services.

The following figure illustrates the process flow for the Availability service.

Figure 1 : The Availability Service

This test reports statistics indicating how healthy the Availability Service is.

Target of the test :A server configured with the Client Access Server role

Agent deploying the test : An internal agent

Outputs of the test : One set of results for the Mailbox server being monitored.

Configurable parameters for the test

Parameters	Description
Test Period	How often should the test be executed.
Host	Indicates the IP address of the Client Access server.
Port	The port number of the client access server. By default, this is 110.

Measurements made by the test

Measurement	Description	Measurement Unit	Interpretation
Availability requests to the web service	Indicates the number of requests serviced per second.	Reqs/Sec	The request can be only for free busy or include suggestions. One request may contain multiple mailboxes. A very low request servicing rate could indicate a processing bottleneck.
Avg. mailboxes processed per request	Indicates the average number of mailboxes processed per request.	Mailboxes/Req
Mailbox connection hits	Indicates the number of mailboxes opened per second without creating a new connection.	Hits/Sec	Ideally, this value should be high. A low cache hit rate could increase processing overheads.
Mailbox connection misses	Indicates the number of mailboxes opened per second, by creating a new connection, because there is no available connection in the cache.	Misses/Sec	Ideally, this measure should be low. A very high cache miss rate could indicate insufficient connections in the cache to service requests. You might want to consider resizing the cache.