Consider six of the most critical metrics to monitor and the value they provide.
Response Metrics
- Average response time is the time between a client’s initial request and the final byte of a server’s response, which includes the delivery of HTML, images, CSS, JavaScript, and any other resources. It is the most precise standard method of determining the actual user experience.
- Peak response time is a roundtrip time measurement for a request/response cycle, but it focuses on the longest cycle rather than an average. Rapid response times assist in identifying potentially problematic anomalies.
- Error Rate quantifies the proportion of problematic requests to total requests. While it is not uncommon for some errors to occur during periods of high load, error rates should be kept to a minimum to optimize the user experience.
Volume Metrics
- Concurrent users indicate the number of virtual users that are active at any given time. While requests per second are comparable (see below), the difference is that each concurrent user can generate a large number of requests.
- Requests per second indicate the total number of requests sent to the server each second, which may include requests for HTML pages, CSS stylesheets, XML documents, JavaScript files, and images, among other resources.
- Throughput indicates the amount of bandwidth consumed during the test in kilobytes per second. Low throughput may indicate the need for resource compression.
References: