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Link: https://www.perfmatrix.com/90th-percentile-in-performance-testing/
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Nicely Explained !! Had read some other as well !! http://performance.punebids.com/?p=628
ReplyDeleteClear explanation. Thank you.
ReplyDeleteClear explanation. Thank you.
ReplyDeleteClearly explained... Nice blog
ReplyDeleteDude, it's very informative and really well explained. Keep doing the same.
ReplyDeletenicely done.
ReplyDeleteThanks Sir
ReplyDeleteNice article Gagan :)
ReplyDelete-Pratim
Thank you so much !
ReplyDeleteHi,
ReplyDeleteSometimes 90% value is greater than the Avg. Response time. what will be the reason and how to explain to the client.
Thanks,
Pawan
Hi Pawan,
Delete90th Percentile value will always be greater than average response time, because to calculate 90th Percentile you ignore 10% of the samples and consider the 90th% value, although average response time is calculated on 100% of samples. Please read one more time my above blog.
While explaining 90th percentile to the client tell her "After eliminating the 10% of high response time, the highest value among 90% is called 90th Percentile of the particular transaction".
You can also use blog's example to clarify your statement.
Hi Gagandeep,
ReplyDeleteThanks for nice explanation.
Can you please give an example for second point under why we need 90th percentile.
Let's consider the response time data set is:
ReplyDelete2,3,3,32,4,3,1,4,1,2
where a major spike had been seen at 4th interval and then system recovered. If you calculate the average of data set then you will find it is 5.5 which is higher than all the values (except spike interval), but when you calculate the 90th percentile you will get 4.
In the large data set (during load test), 0 to 8 % of transactions fall under very high response time due to spikes which may be excluded from the test result. Please note that I would recommend to investigate the root cause of very high spikes, because you can not ignore them all time. It also depends on case to case.
Hi Gagan,
ReplyDeleteCan you please explain about 90%,95% and 99% calculations in Jmeter aggregate report listener.As currently I have 5 samplers which are being executed 9 times each and i see the below result in jmeter aggregate report.
Label #SamplesAverage Median 90% Line95% Line99% LineMin Max Error % Throughput
81 9 612 545 778 808 808 508 808 0.00% 0.78768
89 9 1175 1074 1175 2577 2577 851 2577 0.00% 0.77915
91 9 983 887 1141 1346 1346 843 1346 0.00% 0.76136
95 9 1053 1102 1137 1144 1144 825 1144 0.00% 0.76394
98 9 675 619 844 889 889 606 889 0.00% 0.77929
TOTAL 45 900 864 1141 1175 2577 508 2577 0.00% 2.9758
It would be helpful if you can help me in understanding the same.
Thanks in advance.
Hi,
DeleteLet's try to understand using Transaction Name 81 (Label 81):
1. Average: 612
2. 90%: 778
3. 95%: 808
4. 99%: 808
5. Min: 508
6. Max: 808
If you had the response time of all the 9 iterations (samples) for 'Label 81' then you can easily understand the logic. But still I will try my best to show you how it was calculated using dummy response time.
Since we have Min and Max response time. It means 1st and 9th samplers have values 508 and 808 respectively.
The median is 545, hence it concludes that 5th value is 545.
1st: 508
2nd: A
3rd: B
4th: C
5th: 545
6th: D
7th: E
8th: 778
9th: 808
Now, calculate 99th percentile:
99th Percentile = (0.99 * (Number of Values – 1)) + 1
99th Percentile = (0.99 * (9-1) +1
99th Percentile = (0.99 * 8) + 1
99th Percentile = 7.92 + 1
99th Percentile = 8.92
99th Percentile = 9 (Round-off)
99th Percentile = 9th Value is = 808
Now, calculate 95th percentile:
95th Percentile = (0.95 * (Number of Values – 1)) + 1
95th Percentile = (0.95 * (9-1) +1
95th Percentile = (0.95 * 8) + 1
95th Percentile = 7.60 + 1
95th Percentile = 8.60
95th Percentile = 9 (Round-off)
95th Percentile = 9th Value is = 808
Now, calculate 90th percentile:
90th Percentile = (0.90 * (Number of Values – 1)) + 1
90th Percentile = (0.90 * (9-1) +1
90th Percentile = (0.90 * 8) + 1
90th Percentile = 7.20 + 1
90th Percentile = 8.20
90th Percentile = 8 (Round-off)
90th Percentile = 8th Value (I would assume 8th value could be 778 which you can verify if you have response time of all the samplers)
Thank you Gagan, it really helped me.
Deletevery nicely explained..thank you
ReplyDeletecan average response time and 90 th percentile value same????
ReplyDeleteNo Shivani,
DeleteBoth are different.