Microsoft Exchange Performance Counters

Microsoft Exchange Client Access Server Client Access Server counters

The following table shows some common Client Access server counters for determining load on your servers.

Counter Name	Description
MSExchange ActiveSync\Ping Commands Pending
MSExchange ActiveSync\Requests/sec	Shows the number of HTTP requests received from the client via ASP.NET per second. Used only to determine current user load.
MSExchange ActiveSync\Requests/sec	Shows the number of HTTP requests received from the client via ASP.NET per second. Determines the current Exchange ActiveSync request rate.
MSExchange ActiveSync\Sync Commands/sec	Shows the number of sync commands processed per second. Clients use this command to synchronize items within a folder.
MSExchange Availability Service\Availability Requests (sec)	Shows the number of requests serviced per second. The request can be only for free/ busy information or include suggestions. One request may contain multiple mailboxes. Determines the rate at which Availability service requests are occurring.
MSExchange OWA\Current Unique Users	Shows the number of unique users currently logged on to Outlook Web App. This value monitors the number of unique active user sessions, so that users are only removed from this counter after they log off or their session times out. Determines current user load.
MSExchange OWA\Requests/sec	Shows the number of requests handled by Outlook Web App per second. Determines current user load.
MSExchangeAutodiscover\Requests/sec	Shows the number of Autodiscover service requests processed each second. Determines current user load.
MSExchangeWS\Requests/sec	Shows the number of requests processed each second. Determines current user load.
Web Service(_Total)\Current Connections	Shows the current number of connections established with the Web service. Determines current user load.
Web Service(_Total)\ISAPI Extension Requests/sec	Shows the rate that Internet Server API (ISAPI) extension requests are received by the Web service. Determines current user load. Outlook Anywhere clients make use of this ISAPI extension for RPC over HTTP requests on servers running Windows Server 2003. For Windows Server 2008 counters, see "RPC/HTTP Proxy Counters (Windows Server 2008 Only)" earlier in this topic.
Web Service(_Total)\Other Request Methods/sec	Shows the rate HTTP requests are made that don't use the OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, MOVE, COPY, MKCOL, PROPFIND, PROPPATCH, SEARCH, LOCK, or UNLOCK methods. Determines current user load.
WebService(_Total)\Connection Attempts/sec	Shows the rate that connections to the Web service are being attempted. Determines current user load.