LoadRunner Stuff

Transaction Response Time – Time taken for the application to complete a transaction or business process.

Objective of measuring the Transaction Response Time – to ensure that the application is working perfectly under heavy load. However, the definition of heavy load may vary from system to system. In Loadrunner by defining an initial acceptable response time, we can benchmark the application if it is performing as anticipated.

Measuring transaction response time is important as it gives an idea of how the aplication is performing in terms of time. This performance parameter can be related to the end users at the time of processing request. It helps in understanding how their application performed.

Transaction Response Time is the sum of

• Time taken for the request made to the web server
• Time taken by the web server to process
• Time taken by the application server to process
• Time taken by the database server to process
• Time taken for the procesed request to come back to the client / user through various routes
• Time taken for the request or data in the network transmission is also considered in this – Network latency between the servers and the client

Measuring Transaction Response Time in LoadRuner: It begins when the defined transaction makes a request to the application. From here, till the transaction completes before proceeding with the next subsequent request (in terms of transaction), the time is been measured and will stop when the transaction completes.

How transaction response time is different from Hits Per Seconds: Hits per Seconds is the number of hits made to the web server. These hits can be requests made to the web server for data or graphics. Hits per second measures the number of times the web server is being accessed. So, it does not represent well to users on how well their applications is performing.

Transaction Response Time helps us to find performance bottlenecks in the application. We can further drill down by correlation using other measurements such as the number of virtual users that is accessing the application at the time of measurement. Other system related metrics like CPU Utilization etc. can be used to identify the root cause.

In LoadRuner, after running a performance test, various measurements can be correlated to find trends and bottlenecks. Correlation can be done between the response time, the amount of load that was generated and the payload of all the components of the application.

Users may be unable to understand the meaning of CPU utilization or Memory usage and thus using a common language of time is ideal to convey performance related issues.