Client Access Server Counters

[This topic is in progress.]

The following table shows an Outlook Web App counter.

Counter Description Threshold Troubleshooting

MSExchange OWA\Average Search Time

Shows the average time that elapsed while waiting for a search to complete.

Should be less than 5,000 ms at all times.

The following table shows ASP.NET counters.

Counter Description Threshold Troubleshooting

ASP.NET\Application Restarts

Shows the number of times the application has been restarted during the Web server's lifetime.

Should be 0 at all times.

ASP.NET\Worker Process Restarts

Shows the number of times a worker process has restarted on the computer.

Should be 0 at all times.

ASP.NET\Request Wait Time

Shows the number of milliseconds the most recent request was waiting in the queue.

Should be 0 at all times.

Values greater than this should be investigated.

ASP.NET Applications(*)\Requests In Application Queue

Shows the number of requests in the application request queue.

Should be 0 at all times.

Values greater than this should be investigated.

The following table shows an availability service counter.

Counter Description Threshold Troubleshooting

MSExchange Availability Service\Average Time to Process a Free Busy Request

Shows the average time to process a free/busy request in seconds. One request may contain multiple mailboxes. Free/busy responses do not have meeting suggestions.

Should always be less than 5.

The following table shows ActiveSync service counters.

Counter Description Threshold Troubleshooting

MSExchange ActiveSync\Ping Commands Pending

Ping Commands Pending is the number of Ping commands that are currently pending on the server.

Ping Commands Pending and Sync Commands Pending are the number of hanging requests, which should be almost equal to the number of Direct Push and Hanging sync users.

MSExchange ActiveSync\Sync Commands Pending

Sync Commands Pending is the number of Sync commands that are currently pending on the server.

Ping Commands Pending and Sync Commands Pending are the number of hanging requests, which should be almost equal to the number of Direct Push and Hanging sync users.

MSExchange ActiveSync\Requests Queued

Requests Queued is the number of HTTP requests that are waiting to be assigned to a thread.

Average of 50-100.

The following table shows Windows Server 2008 only RPC/HTTP Proxy counter.

Counter Description Threshold Troubleshooting

RPC/HTTP Proxy\Number of Failed Back-End Connection attempts per Second

Shows the rate at which the RPC proxy attempts are occurring but fail to establish a connection to a back-end server.

Should be 0 at all times.

RPC/HTTP Proxy\Current Number of Incoming RPC over HTTP Connections

Shows the current number of front-end HTTP connections. Determines current user load.

Not applicable.

RPC/HTTP Proxy\Current Number of Unique Users

Shows the number of unique users currently connected to a back-end server via RPC/HTTP. Determines current user load.

Not applicable.

RPC/HTTP Proxy\RPC/HTTP Requests per Second

Shows the rate of RPC/HTTP requests sent to the back-end servers. Determines current Outlook Anywhere load.

Not applicable.

The following table shows RPC Client Access counters.

Counter Description Threshold Troubleshooting

MSExchange RpcClientAccess\RPC Averaged Latency

RPC Averaged Latency is the latency, in milliseconds, averaged for the past 1024 packets.

Should be below 250ms.

MSExchange RpcClientAccess\RPC Operations/sec

RPC Operations/sec is the rate at which RPC operations occur, per second.

MSExchange RpcClientAccess\RPC Requests

RPC Requests is the number of client requests that are currently being processed by the RPC Client Access service.

Should not be over 40.

The following table shows Exchange 2010 address book service counters.

Counter Description Threshold Troubleshooting

MSExchangeAB\NSPI RPC Browse Requests Average Latency

NSPI RPC Browse Requests Average Latency is the average time, in milliseconds, that NSPI browse requests took to complete during the sampling period.

Should be below 1000ms.

MSExchangeAB\NSPI RPC Requests Average Latency

NSPI RPC Requests Average Latency is the average time, in milliseconds, that NSPI requests took to complete during the sampling period.

Should be below 1000ms.

MSExchangeAB\Referral RPC Requests Average Latency

Referral RPC Requests Average Latency is the average time, in milliseconds, that referral requests took to complete during the sampling period.

Should be below 1000ms.

The following table shows Exchange 2010 Control Panel counters.

Counter Description Threshold Troubleshooting

MSExchange Control Panel\Outbound Proxy Requests - Average Response Time

Outbound Proxy Requests - Average Response Time is the average time (in milliseconds) that requests sent to a secondary Client Access server took to complete during the sampling period.

The average should be under 6000ms.

MSExchange Control Panel\Requests - Average Response Time

Requests - Average Response Time is the average time (in milliseconds) the Exchange Control Panel took to respond to a request during the sampling period.

The average should be under 6000ms.

The following table shows Client Access Server Offline Address Book (OAB) download counters.

Counter Description Threshold Troubleshooting

MSExchangeFDS:OAB(*)\Download Task Queued

Should be 0 at all times.

Values greater than 0 indicate a failure to copy OAB data files from Mailbox servers.

MSExchangeFDS:OAB(*)\Download Tasks Completed

Shows the number of OAB download tasks completed since the File Distribution service started. The default value is every 480 minutes or 8 hours.

Should be less than or equal to 3 per day.

Values greater than 3 per day indicate the schedule for the Client Access server to download updated OAB files is not a default schedule.

The following table shows client activity counters.

Counter Description Threshold

MSExchangeIS\RPC Client Backoff/sec

Indicates the rate at which client backoffs are occurring. Higher values may indicate that the server may be incurring a higher load resulting in an increase in overall averaged RPC latencies, causing client throttling to occur. This can also occur when certain client user actions are being performed. Depending on what the client is doing and the rate at which RPC operations are occurring, it may be normal to see backoffs occurring.

Not applicable

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

Counter Description Threshold Troubleshooting

MSExchange ActiveSync\Requests/sec

Shows the number of HTTP requests that are received from the client via ASP.NET per second. Determines the current Exchange ActiveSync request rate.

Not applicable.

MSExchange ActiveSync\Ping Commands Pending

Shows the number of ping commands that are currently pending in the queue. Determines current ping commands pending in the queue.

Not applicable.

MSExchange ActiveSync\Requests/sec

Shows the number of HTTP requests that are received from the client via ASP.NET per second. Stats Only to determine current user load.

Not applicable.

MSExchange ActiveSync\Sync Commands/sec

Shows the number of Sync commands that are processed per second. Clients use this command to synchronize items within a folder. Stats Only to determine current user load.

Not applicable.

MSExchange Availability Service\Availability Requests (sec)

Shows the number of requests serviced per second. The request can be only for free and busy or include suggestions. One request may contain multiple mailboxes. Determines the rate at which Availability service requests are occurring.

Not applicable.

MSExchange OWA\Current Unique Users

Shows the number of unique users currently logged on to Outlook Web Access. 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.

Not applicable.

MSExchange OWA\Requests/sec

Shows the number of requests handled by Outlook Web Access per second. Determines current user load.

Not applicable.

MSExchangeAutodiscover\Requests/sec

Shows the number of Autodiscover service requests that have been processed each second. Determines current user load.

Not applicable.

MSExchangeWS\Requests/sec

Shows the number of requests processed each second. Determines current user load.

Not applicable.

Web Service(_Total)\Current Connections

Shows the current number of connections established with the Web service. Determines current user load.

Not applicable.

WebService(_Total)\Connection Attempts/sec

Shows the rate that connections to the Web service are being attempted. Determines current user load.

Not applicable.

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.

Not applicable.

Web Service(_Total)\Other Request Methods/sec

Shows the rate HTTP requests are made that do not use the OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, MOVE, COPY, MKCOL, PROPFIND, PROPPATCH, SEARCH, LOCK or UNLOCK methods. Determines current user load.

Not applicable.

The following table shows Exchange 2010 Control Panel load counters.

Counter Description Threshold Troubleshooting

MSExchange Control Panel\ASP.Net Request Failures/sec

ASP.Net Request Failures/sec is the number of failures per second detected by ASP.Net in the Exchange Control Panel.

MSExchange Control Panel\Explicit Sign-On Inbound Proxy Requests/sec

Explicit Sign-On Inbound Proxy Requests/sec is the number of Explicit Sign-On requests received from a primary Client Access server per second.

MSExchange Control Panel\Explicit Sign-On Inbound Proxy Sessions/sec

Explicit Sign-On Inbound Proxy Sessions/sec is the number of Explicit Sign-On Inbound Proxy sessions that are loaded per second in the Exchange Control Panel.

MSExchange Control Panel\Explicit Sign-On Outbound Proxy Requests/sec

Explicit Sign-On Outbound Proxy Requests/sec is the number of Explicit Sign-On requests sent to a secondary Client Access server per second.

MSExchange Control Panel\Explicit Sign-On Outbound Session Requests/sec

Explicit Sign-On Outbound Proxy Sessions/sec is the number of Explicit Sign-On Outbound Proxy sessions that are loaded per second in the Exchange Control Panel.

MSExchange Control Panel\Explicit Sign-On Standard RBAC Requests/sec

Explicit Sign-On Standard RBAC Requests/sec is the number of requests received per second by an Explicit Sign-On Standard RBAC session.

MSExchange Control Panel\Explicit Sign-On Standard RBAC Sessions/sec

Explicit Sign-On Standard RBAC Sessions/sec is the number of Explicit Sign-On Standard RBAC sessions that are loaded per second in the Exchange Control Panel.

MSExchange Control Panel\Inbound Proxy Requests/sec

Inbound Proxy Requests/sec is the number of requests received from a primary Client Access server per second.

MSExchange Control Panel\Inbound Proxy Sessions/sec

Inbound Proxy Sessions/sec is the number of Inbound Proxy sessions that are loaded per second in the Exchange Control Panel.

MSExchange Control Panel\Outbound Proxy Requests - Average Response Time

Outbound Proxy Requests - Average Response Time is the average time (in milliseconds) that requests sent to a secondary Client Access server took to complete during the sampling period.

Should be under 6000ms.

MSExchange Control Panel\Outbound Proxy Requests/sec

Outbound Proxy Requests/sec is the number of requests sent to a secondary Client Access server per second.

MSExchange Control Panel\Outbound Proxy Sessions/sec

Outbound Proxy Sessions/sec is the number of Outbound Proxy sessions that are loaded per second in the Exchange Control Panel.

MSExchange Control Panel\PowerShell Runspaces - Activations/sec

PowerShell Runspaces - Activations/sec is the number of Windows PowerShell runspaces that are activated per second in the Exchange Control Panel.

MSExchange Control Panel\PowerShell Runspaces - Average Active Time

PowerShell Runspaces - Average Active Time is the average time (in seconds) that a Windows PowerShell runspace stays active while executing cmdlets in the Exchange Control Panel during the sampling period.

MSExchange Control Panel\PowerShell Runspaces/sec

PowerShell Runspaces/sec is the number of Windows PowerShell runspaces that are created per second in the Exchange Control Panel.

MSExchange Control Panel\RBAC Sessions/sec

RBAC Sessions/sec is the number of RBAC sessions that are loaded per second in the Exchange Control Panel.

MSExchange Control Panel\Requests - Activations/sec

Requests - Activations/sec is the number of requests that are activated per second in the Exchange Control Panel.

MSExchange Control Panel\Requests - Average Response Time

Requests - Average Response Time is the average time (in milliseconds) the Exchange Control Panel took to respond to a request during the sampling period.

Should be under 6000ms.

The following table shows an availability service load counter.

Counter Description Threshold Troubleshooting

MSExchange Availability Service\Availability Requests (sec)

Shows the number of requests serviced per second. The request can be only for free/busy or include suggestions. One request may contain multiple mailboxes. Determines the rate at which Availability service requests are occurring.

The following table shows RPC Client Access load counters.

Counter Description Threshold Troubleshooting

MSExchange RpcClientAccess\Active User Count

Active User Count is the number of unique users that have shown some activity in the last 2 minutes.

MSExchange RpcClientAccess\Connection Count

Connection Count is the total number of client connections maintained.

MSExchange RpcClientAccess\RPC Operations/sec

RPC Operations/sec is the rate at which RPC operations occur, per second.

MSExchange RpcClientAccess\User Count

User Count is the number of users that are connected to the service.

The following table shows Exchange Address Book load counters.

Counter Description Threshold Troubleshooting

MSExchangeAB\NSPI Connections Current

NSPI Connections Current is the number of NSPI clients that are currently connected to the server.

MSExchangeAB\NSPI Connections/sec

NSPI Connections/sec is the number of NSPI client connections that are established to the server each second.

MSExchangeAB\NSPI RPC Requests/sec

NSPI RPC Requests/sec is the rate at which NSPI requests occur each second.

MSExchangeAB\Referral RPC Requests/sec

Referral RPC Requests/sec is the rate at which referral requests occur each second.