How to analyze a JMeter summary report?

问题:

I get the following result when I run a load test. Can any one help me to read the report?

the number of thread = '500 '
ramp up period = '1'

Sample      =       '500'
Avg     =       '20917'
min         =       '820'
max         =       '48158'
Std Deviation   =       '10563.178194669255'
Error %     =       '0.046'
throughput      =       '10.375381295262601'
KB/Sec          =       `247.05023046315702` 
Avg. Bytes      =       '24382.664'

回答1:

Short explanation looks like:

1. Sample - number of requests sent
2. Avg - an Arithmetic mean for all responses (sum of all times / count)
3. Minimal response time (ms)
4. Maximum response time (ms)
5. Deviation - see Standard Deviation article
6. Error rate - percentage of failed tests
7. Throughput - how many requests per second does your server handle. Larger is better.
8. KB/Sec - self expalanatory
9. Avg. Bytes - average response size

If you having troubles with interpreting results you could try BM.Sense results analysis service

回答2:

Sample: Number of requests sent.

The Throughput: is the number of requests per unit of time (seconds, minutes, hours) that are sent to your server during the test.

The Response time: is the elapsed time from the moment when a given request is sent to the server until the moment when the last bit of information has returned to the client.

The throughput is the real load processed by your server during a run but it does not tell you anything about the performance of your server during this same run. This is the reason why you need both measures in order to get a real idea about your server’s performance during a run. The response time tells you how fast your server is handling a given load.

Average: This is the Average (Arithmetic mean μ = 1/n * Σi=1…n xi) Response time of your total samples.

Min and Max are the minimum and maximum response time.

An important thing to understand is that the mean value can be very misleading as it does not show you how close (or far) your values are from the average.For this purpose, we need the Deviation value since Average value can be the Same for different response time of the samples!!

Deviation: The standard deviation (σ) measures the mean distance of the values to their average (μ).It gives you a good idea of the dispersion or variability of the measures to their mean value.

The following equation show how the standard deviation (σ) is calculated:

σ = 1/n * √ Σi=1…n (xi-μ)2

For Details, see here!!

So, if the deviation value is low compared to the mean value, it will indicate you that your measures are not dispersed (or mostly close to the mean value) and that the mean value is significant.

Kb/sec: The throughput measured in Kilobytes per second.

Error % : Percent of requests with errors.

An example is always better to understand!!! I think, this article will help you.

回答3:

The JMeter docs say the following:

The summary report creates a table row for each differently named request in your test. This is similar to the Aggregate Report , except that it uses less memory. The thoughput is calculated from the point of view of the sampler target (e.g. the remote server in the case of HTTP samples). JMeter takes into account the total time over which the requests have been generated. If other samplers and timers are in the same thread, these will increase the total time, and therefore reduce the throughput value. So two identical samplers with different names will have half the throughput of two samplers with the same name. It is important to choose the sampler labels correctly to get the best results from the Report.

• Label - The label of the sample. If "Include group name in label?" is selected, then the name of the thread group is added as a prefix. This allows identical labels from different thread groups to be collated separately if required.
• # Samples - The number of samples with the same label
• Average - The average elapsed time of a set of results
• Min - The lowest elapsed time for the samples with the same label
• Max - The longest elapsed time for the samples with the same label
• Std. Dev. - the Standard Deviation of the sample elapsed time
• Error % - Percent of requests with errors
• Throughput - the Throughput is measured in requests per second/minute/hour. The time unit is chosen so that the displayed rate is at least 1.0. When the throughput is saved to a CSV file, it is expressed in requests/second, i.e. 30.0 requests/minute is saved as 0.5.
• Kb/sec - The throughput measured in Kilobytes per second
• Avg. Bytes - average size of the sample response in bytes. (in JMeter 2.2 it wrongly showed the value in kB)

Times are in milliseconds.

回答4:

There are lots of explanation of Jmeter Summary, I have been using this tool from quite some time for generating performance testing report with relevant data. The explanation available on below link is right from the field experience:

Jmeter:Understanding Summary Report

This is one of the most useful report generated by Jmeter to undertstand the load test result.

# Label: Name of HTTP sample request send to server

# Samples : This Captures the total number of samples pushed to server. Suppose you put a Loop Controller to run it 5 times this particular request and then 2 iteration(Called Loop Count in Thread Group)is set and load test is run for 100 users, then the count that will be displayed here .... 1*5*2 * 100 =1000. Total = total number of samples send to server during entire run.

# Average : It's an average response time for a particular http request. This response time is in millisecond, and an average for 5 loops in two iteration for 100 users. Total = Average of total average of samples, means add all averages for all samples and divide by number of samples

# Min : Minmum time spend by sample requests send for this label. The total equals to the minimum time across all samples.

# Max : Maximum tie spend by sample requests send for this label The total equals to the maxmimum time across all samples.

# Std. Dev. : Knowing the standard deviation of your data set tells you how densely the data points are clustered around the mean. The smaller the standard deviation, the more consistent the data. Standard deviation should be less than or equal to half of the average time for a label. If it is more than that, then it means that something is wrong. you need to figure out the problem and fix it. https://en.wikipedia.org/wiki/Standard_deviation Total is euqals to highest deviation across all samples.

# Error: Total percentage of erros found for a particular sample request. 0.0% shows that all requests completed successfully. Total equals to percentage of errors samples in all samples (Total Samples)

# Throughput: Hits/sec, or total number of request per unit of time(sec, mins, hr) send to server during test.

endTime = lastSampleStartTime + lastSampleLoadTime
startTime = firstSampleStartTime
converstion = unit time conversion value
Throughput = Numrequests / ((endTime - startTime)*conversion)

# KB/sec : Its mesuring throughput rate in Kilobytes per second.

# Avg. Bytes: Avegare of total bytes of data downloaded from server. Totals is average bytes across all samples.

回答5:

A Jmeter Test Plan must have listener to showcase the result of performance test execution.

• Listeners capture the response coming back from Server while Jmeter runs and showcase in the form of – tree, tables, graphs and log files.

• It also allows you to save the result in a file for future reference. There are many types of listeners Jmeter provides. Some of them are: Summary Report, Aggregate Report, Aggregate Graph, View Results Tree, View Results in Table etc.

Here is the detailed understanding of each parameter in Summary report.

Label: It is the name/URL for the specific HTTP(s) Request. If you have selected “Include group name in label?” option then the name of the Thread Group is applied as the prefix to each label.

Samples: This indicates the number of virtual users per request.

Average: It is the average time taken by all the samples to execute specific label. In our case, average time for Label 1 is 942 milliseconds & total average time is 584 milliseconds.

Min: The shortest time taken by a sample for specific label. If we look at Min value for Label 1 then, out of 20 samples shortest response time one of the sample had was 584 milliseconds.

Max: The longest time taken by a sample for specific label. If we look at Max value for Label 1 then, out of 20 samples longest response time one of the sample had was 2867 milliseconds.

Std. Dev.: This shows the set of exceptional cases which were deviating from the average value of sample response time. The lesser this value more consistent the data. Standard deviation should be less than or equal to half of the average time for a label.

Error%: Percentage of Failed requests per Label.

Throughput: Throughput is the number of request that are processed per time unit(seconds, minutes, hours) by the server. This time is calculated from the start of first sample to the end of the last sample. Larger throughput is better.

KB/Sec: This indicates the amount of data downloaded from server during the performance test execution. In short, it is the Throughput measured in Kilobytes per second.