29. Access log sampler Step-by-step¶

+ +

+This is a short tutorial on JMeter's access log sampler. The purpose of the Access Log Sampler +is to provide an easy way to simulate production traffic. There are several benefits to using access logs. +

+ +

Rather than guess what users are doing, the test plan is using real traffic data
As the traffic pattern changes, the access log provides a record of individual changes and general shifts in usage
Access logs contain a lot of useful data, which may provide some insight
Access logs can be minded to determine different types of users
Access logs can capture detailed session information

+ +

+The down side of using access logs for test plans is you have to configure the webserver to output the request +information. This may not be appropriate where security is an issue. For example, if the webserver dumps the post +data from each request to the access logs, users login and password would be stored in plain text. Here are some +general cases where access logs might be inappropriate. +

+ +

Security sensitive applications where the data is encrypted
The application does not allow fine grain control of which request parameters are written to the access logs
The application needs correlation between requests
The webserver cannot be configured to append the post data to the access log
The webserver is hosting multiple applications, but doesn't provide a way to log the requests of one application to a separate file

+ +

+To take advantage of access logs, the first thing is the webserver needs to be configured to use extended +log format. Links for configuring the popular containers are provided below. +

+ +

+In some cases, it may be desirable to write custom logging, so that sensitive information is not written +to the access logs. This article does not cover the techniques for writing custom logging. +

+ +

29.1 Step-by-Step¶

+ +

Start JMeter
Select Test Plan
Right click + Add → Threads (Users) → Thread Group +
Add Thread Group
+
Select Thread Group
Right click + Add → Sampler → Access Log Sampler +
Add Access Log Sampler
+
Right click on Thread Group + Add → Listener → Aggregate Report +
Add Aggregate Report
+
Select the Access Log Sampler +
Access Log Sampler
+
Enter the IP address or hostname in Server
Enter the port in Port
If you want to download the images, set Parse images to true.
Select a file for Log File Location +
Filled in Access Log Sampler
+
Select Aggregate Report
Enter results.jtl for filename +
Aggregate Report with filename
+

+ +

+At this point, the test plan is ready. Start the test with + Ctrl + R +or from the menu + Start → Run. +

+ +

26. Apache JMeter Distributed Testing Step-by-step¶

+ +

+This short tutorial explains how to use multiple systems to perform stress testing. Before we start, there are a couple of things to check. +

+ +

the firewalls on the systems are turned off or correct ports are opened.
all the clients are on the same subnet.
the server is in the same subnet, if 192.x.x.x or 10.x.x.x IP addresses are used. + If the server doesn't use 192.xx or 10.xx IP address, there shouldn't be any problems.
Make sure JMeter can access the server.
Make sure you use the same version of JMeter and Java on all the systems. Mixing versions will not work correctly.

+ +

+Once you've made sure the systems are ready, it's time to setup remote testing. The tutorial assumes you already +have JMeter installed on all the systems. The way JMeter works is one master controller initiates the test on multiple slave systems. +

+ +

In this tutorial we use GUI Mode just for demonstration. In real life you should use NON GUI mode to start your load test

+ +

+ +

26.1 Terminology¶

+ +

+Before we dive into the step-by-step instructions, it's a good idea to define the terms and make sure the definition is clear. +

+ +

Master: the system running JMeter GUI, which controls the test
Slave: the system running jmeter-server, which takes commands from + the GUI and send requests to the target system(s)
Target: the webserver we plan to stress test

+ +

+ +

26.2 Step-by-Step¶

+ +

On the slave systems, go to jmeter/bin directory and execute + jmeter-server.bat (jmeter-server on unix). +
On master system acting as the console, open windows explorer and go to + jmeter/bin directory
Open jmeter.properties in a text editor
Edit the line remote_hosts=127.0.0.1
Add the IP address. For example, if I have JMeter server running on 192.168.0.10, + …, 192.168.0.15, the entry would like like this: +
```
remote_hosts=192.168.0.10,192.168.0.11,192.168.0.12,192.168.0.13,192.168.0.14
```
+
Start JMeter.
Open the test plan you want to use

+ +

+ +

26.2 Starting the Test¶

+ +

+At this point, you are ready to start load testing. If you want to double check +the slave systems are working, open jmeter.log in your editor. You should see the following in the log. +

+ +

+Writing log file to: /XXXX/XXXXX/bin/jmeter-server.log
+Created remote object: UnicastServerRef [liveRef: [endpoint:[192.X.X.X:XXXXX](local),objID:[-6a665beb:15a2c8b9419:-7fff, 3180474504933847586]]]
+

+ +

+If you do not see this message, it means jmeter-server did not start correctly. For tips on +debugging the issue, go to the tips section. There are two ways to +initiate the test: a single system and all systems. +

+ +

26.3 Start a single clients¶

+ +

Click Run at the top
Select Remote Start
Select the IP address

+ +

+ +

26.4 Start all clients¶

+ +

Click Run at the top
Select Remote Start all or use Ctrl + Shift + R

+ +

+ +

26.5 Limitations¶

+ +

+There are some basic limitations for distributed testing. Here's the list of the known items in no specific order. +

+ +

RMI cannot communicate across subnets without a proxy; therefore neither can JMeter without a proxy.
Since version 2.9, JMeter sends all the test results stripping Response data to the controlling console, this allows + us to reduce impact on network IO. Ensure you monitor your network traffic so that this trafic does not incur contention
A single JMeter client running on a 2-3 GHz CPU (recent CPU) can handle 1000-2000 threads depending on the type of test.

+ +

26.6 Additional resources¶

+ +

+ Wiki page on remote testing +

+ +

+ Remote Testing in the user manual +

+ +

26.7 Tips¶

+ +

+In some cases, the firewall may still be blocking RMI traffic. +

+ +

Anti Virus and Firewall

+ +

Antivirus should be stopped during a Load Test as it can drastically impact timings leading to wrong results.

+Firewall needs to be stopped from windows services or at least some ports need to be opened. +

+ +

Open control panel
Open administrative tools
Double click services
Go to down to Symantec anti virus, right click and select stop

+ +

Windows firewall

+ +

Open network connections
Select the network connection
Right click and select properties
Select advanced tab
Uncheck internet connection firewall

+ +

Linux

+ +

+On Linux, iptables might be turned on by default. For instructions, please refer to the + Remote Testing in the user manual +

+ +

+On RedHat (or derivatives), iptables is turned on by default. Execute +

service iptables stop

+to stop the Linux firewall or ensure you open the correct ports. +

+ +

27. Apache JMeter HTTP(S) Test Script Recorder¶

+ +

+This tutorial attempts to explain the exact steps for recording HTTP/HTTPS. For those new to JMeter, one easy way to create a test plan is to use the Recorder. +

+ +

27.1 JMeter configuration¶

+ +

+Since JMeter 2.10, recording has been improved to better handle embedded resources and creation of certificates on the fly. +To enable these features, JMeter uses keytool utility (available in JRE/JDK) so you need to ensure your +configuration is correct, read this wiki page before starting. +

+ +

27.2 Basic Instructions¶

+ +

Go to JMETER_HOME/bin and start JMeter with jmeterw.cmd on Windows + and jmeter on Linux/Unix
Select Templates... on the menu bar

Select Recording template on the list

A complete Test Plan is generated

In the HTTP Request Defaults element: +
+
Server name
enter example.com
+
Path
leave blank
+
+
+
Return to HTTP(S) Test Script Recorder, and click the Start button at the top.

+ +

+This will start the JMeter proxy server which is used to intercept the browser requests. +A file called ApacheJMeterTemporaryRootCA.crt will be generated in jmeter/bin +folder. Install this certificate in your browser, if you don't know how to do it, +read Installing the JMeter CA certificate for HTTPS recording +

+ +

27.3 Configure your browser to use the JMeter Proxy¶

+ +

+At this point, JMeter's proxy is running. For this exercise, we will use Iceweasel/Firefox +to view some pages on the JMeter website. +

+ +

Start Iceweasel/Firefox, but do not close JMeter.
From the tool bar, click + Edit → Preferences (or + Tools → Preferences or type about:preferences#advanced + as URL). This should bring up the options. +
+
Select the Advanced tab, and Network tab
Click Settings button near the top.
On the new pop-up, check Manual proxy configuration. The address and + port fields should be enabled now. +
+
Address
enter localhost or the IP address of your system
+
Port
enter 8888.
+
+
+
Check Use this proxy server for all protocols
Click OK button. This should return you to the browser

+ +

With your browser, in the Address bar at the top, enter http://example.com/index.html (replace example.com with your websites address). + and hit the enter key.
Click on a few links on your sites pages.
Close your browser and bring up the JMeter window.

+ +

+Expand the Thread Group and there should be several samplers. At this point, the test plan can +be saved as is. +

If you forget to add default HTTP Request settings, you will have to manually +delete the server name, and port.

+ +

+In this sample, there aren't any default request parameters. If a particular request parameter +is required by all pages, the request defaults is where one would add the entries. +

+ +

Select Thread Group and change a few defaults: +
+
Number of Threads
enter 5
+
Ramp-Up Period
do not change
+
Loop Count
enter 100
+
+
+

+ +

27.5 Validate the script¶

+ +

+Now we need to validate the script before to run our test plan. Save the test plan. +

+Right click on the Thread Group + Validate +

+Check with View Results Tree element if all is ok. +

+ +

27.6 Variabilize and Correlate the script¶

+In some scripts, we will need to: +

Variabilize some input (login, password, search words...)
Correlate some data (session variable...) between two requests

+To variabilize, we can use: +

CSV Data Set Config to get input data from csv file
JMeter functions like __counter, __time...
etc.

+To correlate, we can get data from a request with Post Processors like JSON Extractor, Regular Expression Extractor... and inject it in another request. +

+To find data to correlate, the easiest way to do it is to use the Search function in View Results Tree. +

+ +

27.7 Start the test¶

+ +

+At this point, we are ready to run our test plan and see what happens. When you're +ready to run the test, there are two ways: +

With the gui, but it's not recommended to big load test.
With the command line.

+ + +

+Solution 1, with the gui, but just during debug phase, use Non GUI for your load test. +

+ Run → Start +or use the keyboard and press Ctrl + R +

+ +

+ Before you start the test, add a Summary Report element and select it. As the test runs, the statistics will change + until the test is done. At the end of the test, the summary report should look like this. +