Monitoring and Tuning Your Server
Monitoring and Tuning Your Server |
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If the bandwidth of your server is insufficient to handle its workload, it is likely that clients will be aware of it before the server is. Client requests to the server will be rejected or will time out, or the response will be delayed. On the server side, the indicators are less clear. The server will continue to establish connections, receive requests, and transmit data.
Bandwidth shortages are not uncommon. You can detect one on your server (perhaps even before clients do) by monitoring the success and failure of connections established and rejected by TCP. With ample bandwidth, the server can establish and serve connections before they time out. If it is not sufficient, the connections fail.
The counters on the TCP object are the best indicators of the success of connection requests. The counters on the Web Service and FTP Service performance objects monitor connections maintained by each IIS 5.0 service. The counters on these objects display only successful connection requests. They do not display failed attempts to connect to these IIS 5.0 services. Like all counters at the Application Layer, they do not have information about connections until the connections are established. Performance counters that display the number of simultaneous connections maintained by IIS 5.0 are discussed in the topic Preventing Processor Bottlenecks earlier in this section.
Table 5.12 lists and describes the counters that monitor the success and failure of connections to TCP.
Table 5.12 Counters for Monitoring TCP Connection Successes and Failures
| Counter | Indicates |
| TCP\ Connections Established | The number of simultaneous connections supported by TCP (at last observation). This counter displays the number of connections last observed to be in the ESTABLISHED or CLOSE-WAIT state. It displays the last observed value only; its value is not an average. |
| TCP\ Connection Failures | The number of connections that have failed since the service was started (regardless of when PerfMon was started). TCP counts a connection as having failed when it goes directly from sending (SYNC-SENT) or receiving (SYNC-RCVD) to CLOSED or from receiving (SYNC-RCVD) to listening (LISTEN). |
| TCP\ Connections Reset | The number of connections reset since the service was started (regardless of when PerfMon was started).
TCP counts a connection as having been reset when it goes directly from ESTABLISHED or CLOSE-WAIT to CLOSED. |
You can also use the HTTP Monitoring Tool or a similar tool to monitor the functioning of the server. For more information about the HTTP Monitoring Tool, see Tools in this section.