Counter data can be viewed in Performance Monitor, in third-party client software, or in a custom application that uses one of the two protocols that allow you to access performance counters. The two protocols are Simple Network Management Protocol (SNMP) and Performance Data Helper (PDH), compared in the table below. Protocol helper files must not be edited. If you choose to write your own custom application to access performance counters, the helper files are there for you as a reference. The interfaces for both protocols are documented in the MSDN Online library.
| Protocol | PDH | SNMP |
|---|---|---|
| Used by | Performance Monitor (or a custom application). | Third-party client software, sometimes called MIB Browsers (or a custom application). |
| Setup | Installed by default. | It must be selected under Management and Monitoring Tools during Windows installation or from Add/Remove Programs. |
| IIS Helper Files | Ftpctrs.ini W3ctrs.ini Infoctrs.ini Axperf.ini |
Ftp.mib Inetsrv.mib Http.mib |
| Helper Files Contain | Identifier names, counter names, descriptions. | Identifier names, counter names, descriptions, unique object identification numbers (OIDs), other attributes such as accessibility and status. |
| Advantages | Easier programming interface. More stable and robust since Microsoft software uses it. Accessible from WMI. | SNMP is familiar to users of other operating systems. Accessible from WMI. Although all IIS counters are read-only, SNMP is a management protocol, allowing you to write values where possible. |
| Disadvantages | PDH is a monitoring protocol more than a management protocol; you cannot write values. | The helper files rely heavily on ordering and OIDs, so it is hard to add counters. |
The Web and FTP Service object counters installed with Internet Information Server monitor file transfer rates, bandwidth usage, connection rates, errors and numbers & types of users. You can view performance data for all instances of this object (using the _Total instance) or for specific instances, such as the Default Web/FTP Site or Administration Web Site instances. The IIS Global object counters report performance data for all IIS services. The Active Server Pages object counters monitor connection activity for scripts including runtime errors, requests, sessions, templates, and transactions.
The IIS performance counters are arranged below by job type. The counter names match those in the PDH helper files. All IIS counters are read-only. To see an alphabetic listing of counters and their descriptions, click any counter name below. To read more about Performance Monitor, see About Performance Tuning.
| Objects | Counter |
|---|---|
| IIS Global, Web | Current Blocked Async I/O Requests |
| IIS Global, Web | Measured Async I/O Bandwidth usage |
| IIS Global, Web | Total Allowed Async I/O Requests |
| IIS Global, Web | Total Blocked Async I/O Requests |
| IIS Global, Web | Total Rejected Async I/O Requests |
| Objects | Counter |
|---|---|
| Web, FTP | Bytes Received/sec |
| Web, FTP | Bytes Sent/sec |
| Web, FTP | Bytes Total/sec |
| Web | Files/sec |
| Web | Files Received/sec |
| Web | Files Sent/sec |
| Web, FTP | Total Files Received |
| Web, FTP | Total Files Sent |
| Web, FTP | Total Files Transferred |
| Objects | Counter |
|---|---|
| Web | Anonymous Users/sec |
| Web | Connection Attempts/sec |
| Web, FTP | Current Anonymous Users |
| Web, FTP | Current CAL Count for Authenticated Users |
| Web, FTP | Current CAL Count for SSL connections |
| Web, FTP | Current Connections |
| Web, FTP | Current NonAnonymous Users |
| Web, FTP | Logon Attempts/sec |
| Web, FTP | Maximum Anonymous Users |
| Web, FTP | Maximum CAL Count for Authenticated Users |
| Web, FTP | Maximum CAL Count for SSL connections |
| Web, FTP | Maximum Connections |
| Web, FTP | Maximum NonAnonymous Users |
| Web, FTP | Nonanonymous Users/sec |
| Web, FTP | Total Anonymous Users |
| Web, FTP | Total Connection Attempts |
| Web, FTP | Total Count of failed CAL Requests for Authenticated Users |
| Web, FTP | Total Count of failed CAL Requests for SSL connections |
| Web, FTP | Total Logon Attempts |
| Web, FTP | Total NonAnonymous Users |
| Objects | Counter |
|---|---|
| IIS Global | Active Flushed Entries |
| IIS Global | BLOB Cache Flushes |
| IIS Global | BLOB Cache Hits |
| IIS Global | BLOB Cache Hits % |
| IIS Global | BLOB Cache Misses |
| IIS Global | Current BLOBs Cached |
| IIS Global | Current File Cache Memory Usage |
| IIS Global | Current Files Cached |
| IIS Global | Current URIs Cached |
| IIS Global | File Cache Flushes |
| IIS Global | File Cache Hits |
| IIS Global | File Cache Hits % |
| IIS Global | File Cache Misses |
| ASP | In Memory Cache Hit Rate |
| ASP | In Memory Templates Cached |
| IIS Global | Maximum File Cache Memory Usage |
| ASP | Memory Allocated |
| ASP | Script Engines Cached |
| ASP | Templates Cached |
| ASP | Template Cache Hit Rate |
| ASP | Template Notifications |
| IIS Global | Total BLOBs Cached |
| IIS Global | Total Files Cached |
| IIS Global | Total Flushed BLOBs |
| IIS Global | Total Flushed Files |
| IIS Global | Total Flushed URIs |
| IIS Global | Total URIs Cached |
| IIS Global | URI Cache Flushes |
| IIS Global | URI Cache Hits |
| IIS Global | URI Cache Hits % |
| IIS Global | URI Cache Misses |
| Objects | Counter |
|---|---|
| ASP | Session Duration |
| ASP | Sessions Current |
| ASP | Sessions Timed Out |
| ASP | Sessions Total |
| Objects | Counter |
|---|---|
| ASP | Transactions Aborted |
| ASP | Transactions Committed |
| ASP | Transactions Pending |
| ASP | Transactions Total |
| ASP | Transactions/sec |
| Objects | Counter |
|---|---|
| Web, FTP | (FTP) Service Uptime |