Service Level Monitoring

This chapter describes Service Level Monitoring, and how to configure the Traffic Manager to use Service Level Monitoring to monitor the response times on your network.

Service Level Monitoring is not available on all Traffic Manager variants. If required, it can be obtained via a software or license key upgrade.

Introducing Service Level Monitoring

Service response times are a key metric for Web services, as lower response times imply a more responsive and usable service. The response time used by Service Level Monitoring is the time in milliseconds taken from the Traffic Manager receiving a request to then sending the first byte of response data back to the client. It does not include the time taken to return the content to the client on the Internet, and generally is not affected by the speed of the remote network.

Response time includes the time taken for internal processing on the Traffic Manager (for example, running TrafficScript rules and Java Extensions), the time taken to send the request to the back-end node, the time taken for the node to generate and return the first data in the response, and the time taken to run any response rules. Response time is generally independent of the speed or latency of the client connection, so gives an accurate measure of the performance of the internal systems an application administrator can tune and optimize.

If additional data, such as HTTP POST body data, needs to be read from the client before the node returns a response, the time taken to read this data is included in the response time measurement.

Using Service Level Monitoring, the Traffic Manager can measure and react to changes in response times for your nodes, by comparing response times to a conformance value. You can obtain a graph of response times and other related information, or issue alerts or log when response times are below the conformance value. The Traffic Manager also has the ability to dynamically adjust the resources available based on response times, using TrafficScript rules.