Using Transaction – Percentile Graph
Posted: October 24th, 2008 | Author: TnT Admin | Filed under: How-Tos | Tags: Analyze, Graphs | 6 Comments »In LoadRunner, the percentile graph is a great graph for understanding how well the system is performing in terms of transaction response time from an overall perspective in a load test. How is the percentile graph derived? The mathematical explanation/formula can be found in Wiki, Percentile rank.
90% percentile allows us to know that for a certain amount of transactions are performing at a certain amount of duration. Of course it’s a really abstract description but anyway how is it useful? Example, if the 90th Percentile is 10secs, what it literally means is that 90% of all transactions are performing at or under 10secs. While the remaining 10% are performing more than 10secs. If you have a SLA or performance requirements that is based on 90% of the transactions to perform under 8secs, you have pass this criteria.
The Percentile can also tell you how the system is performing, such that if there is a higher percentage of slow response time transaction and what is the percentage that is performing higher than the expected transaction response time. In a typical average transaction response time graph, you can see how the (passed) transactions are performing during the entire load test period over time. However, the Percentile graph illustrates the (passed) transactions and their percentage with respect to the overall transactions.
In the below example taken from the Analysis User Guide, at the 60th Percentile, tr_amazon_help is at about 4secs, which means 60% and less of tr_amazon_help is responding at 4secs less. While at the 90th Percentile, 90% of all tr_cnn_weather transactions are responding at 20secs or less.
what documented: While the remaining 10secs are performing more than 10secs. What should be: While the remaining 10% are performing more than 10secs.
Thanks Kannan, I’ve got to admit, I’ve made quite a few mistakes in my recent posts. Thanks for pointing out!
Hi, I have to test a web based .net application with the following details: Databse : Oracle 9i Communication protocol : http So can i use HTML/HTTP protocol…. also, I have to load 2500 vusers, so how many loadgenerators do i need to use?I mean that what should be the approximate umber of vuser that should be loaded on loadgenerators. Load generators are located at client side..whereas VUGen and Controller are installed on our system. Please suggest.
Protocol used is Web (HTTP/HTML) as you’ve mentioned. Controller can be anywhere. Refer to the following resources to understand how to setup an environment for load testing.
* What’s LoadRunner?
* 4 points to note for scenario execution
* What happens when the scenario is executed?
* How does the monitoring work in LoadRunner?
* 4 Monitoring Implementation Models
The above should help you with a lot on the basics of load test environment setup.
The number of load generators is dependent on the number of vusers that it should be generating and the amount of memory it consumes during the load test. Another thing to note is the bandwidth of the Network Interface Card that may also be a probable bottleneck in load generation. Ensure the NIC has sufficient bandwidth to generate/receive load.
how can i know about anaysis and monitoring? will u please explain to me?
As mentioned in previous comments,refer to our section of Analyze