--- title: How to Record a Scenario with JMeter url: https://blog.octoperf.com/how-to-record-a-scenario-with-jmeter/ date: '2018-04-26' authors: - jloisel categories: - JMeter tags: - Recording - HTTP - Proxy - JMeter description: Learn how to use the JMeter built-in http(s) recorder to record HTTP and HTTPS traffic directly from a web browser (like Firefox or Chrome). --- # How to Record a Scenario with JMeter So you started designing a scenario using [JMeter](https://jmeter.apache.org/) manually. After working a while on this grueling task, you start wondering: **Isn't there a way to record browser interactions with JMeter?** The short answer is **yes**! [Jmeter's HTTP(s) Test Script Recorder](https://jmeter.apache.org/usermanual/component_reference.html#HTTP(S)_Test_Script_Recorder) is exactly designed to **record test scenarios**. This tutorial teaches you: - What a [Proxy](https://en.wikipedia.org/wiki/Proxy_server) is and **how the recorder works**, - **How to intercept and record HTTP Requests** automatically while using your [web browser](https://en.wikipedia.org/wiki/Web_browser), - How to record [SSL-secured](https://en.wikipedia.org/wiki/Transport_Layer_Security) (`https` requests), - **How to configure Proxy Settings** with [Google Chrome](https://www.google.com/chrome/index.html) and [Firefox](https://www.mozilla.org/), - And the most important part: **recording the script**! You'll see **there are a few caveats** but everything is well explained. We assume you already: - Have **JMeter** installed (See for [Mac Setup](https://blog.octoperf.com/how-to-install-jmeter-on-a-mac/) and [Windows Setup](https://blog.octoperf.com/how-to-install-jmeter-on-windows/)), - And know [How to use JMeter](https://blog.octoperf.com/jmeter-tutorial-for-beginners/). I know *how impatient you are*, so **let's start now**! ## Recorder Setup ### How a Proxy works ![How Proxy Works](https://blog.octoperf.com/img/blog/jmeter-recording/how-proxy-work.png "Picture showing Proxy Principle") Before we configure JMeter, let me briefly explain how the recording process works. A [Proxy](https://en.wikipedia.org/wiki/Proxy_server) is a component which **inserts between you and the remote server**. In some way, it's similar to a [Man-In-The-Middle Attack](https://en.wikipedia.org/wiki/Man-in-the-middle_attack), except you're **spying on yourself**! As **anything** between the remote server and you **goes through the Proxy**, when *JMeter* acts like a Proxy, it can record all your browser interactions (given it's [http](https://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol) or [https](https://en.wikipedia.org/wiki/HTTPS)). **How can JMeter act like a Proxy**? By using [Jmeter's HTTP(s) Test Script Recorder](https://jmeter.apache.org/usermanual/component_reference.html#HTTP(S)_Test_Script_Recorder). ### JMeter Recorder Template The easiest way to get started right away is to use the `Recorder Template`: - Launch JMeter, - Click on `Files > Templates...`, - Select `Recorder` from *Select Template* dropdown, - Then click on `Create`. ![JMeter Recording Template](https://blog.octoperf.com/img/blog/jmeter-recording/jmeter-recording-template.png "Templates panel accessible from `Files > Templates`") Once you click on *Create*, JMeter creates a bunch of elements required to properly **record http and https traffic**. Let's examine the elements being created. ![JMeter Recording Test Elements](https://blog.octoperf.com/img/blog/jmeter-recording/jmeter-recording-test-elements.png "JMeter Recording Test Elements") Your JMX project should now contain the following elements. - [User Defined Variables](https://jmeter.apache.org/usermanual/component_reference.html#User_Defined_Variables): lets you define an initial set of variables, just as in the **Test Plan**, ![User Defined Variables](https://blog.octoperf.com/img/blog/jmeter-recording/user-defined-variables.png) - [HTTP Request Defaults](https://jmeter.apache.org/usermanual/component_reference.html#HTTP_Request_Defaults): lets you set default values that your *HTTP Request* controllers use, ![HTTP Request Defaults](https://blog.octoperf.com/img/blog/jmeter-recording/http-request-defaults.png) - [HTTP Cookies Manager](https://jmeter.apache.org/usermanual/component_reference.html#HTTP_Cookie_Manager): stores and sends cookies just like a web browser, ![HTTP Cookies Manager](https://blog.octoperf.com/img/blog/jmeter-recording/http-cookies-manager.png) - [Thread Group](https://jmeter.apache.org/usermanual/component_reference.html#Thread_Group) with a [Recording Controller](https://jmeter.apache.org/usermanual/component_reference.html#Recording_Controller) inside: it will contain the request being recorded by JMeter's proxy, ![Thread Group](https://blog.octoperf.com/img/blog/jmeter-recording/thread-group.png) - And finally the [HTTP(S) Test Script Recorder](https://jmeter.apache.org/usermanual/component_reference.html#HTTP(S)_Test_Script_Recorder): controls JMeter's Proxy settings. ![Test Script Recorder](https://blog.octoperf.com/img/blog/jmeter-recording/jmeter-http-recorder.png) A few [View Results Tree](https://blog.octoperf.com/jmeter-result-analysis-the-ultimate-guide/#view-results-tree) are located here and there **for debugging purpose**. ### Test Script Recorder Settings Let's now examine the **most interesting Script Recorder Settings**: - **Global Settings** - **Port**: HTTP and HTTPS proxy port. The proxy will be running on this [TCP](https://en.wikipedia.org/wiki/Transmission_Control_Protocol) port, listening for http requests, - **HTTPS Domains**: List of domain (or host) names for HTTPS. Use this to **pre-generate certificates** for all servers you wish to record. Example: `httpbin.org`, - **Test Plan Content**: - **Target Controller**: by default, everything is recorded within `Recording Controller`. But you can change it to whatever you want (like the `Thread Group` directly), - **Grouping**: groups http request by trying to determine which requests belong to the same page, - **Capture HTTP Headers**: creates [HTTP Headers Manager](https://jmeter.apache.org/usermanual/component_reference.html#HTTP_Header_Manager) as http request child, capturing the headers sent by the web browser. **Leave checked** as most http headers are important, - **HTTP Sampler Settings**: - **Use Keep-Alive**: enable [HTTP Keep-Alive](https://en.wikipedia.org/wiki/Keepalive#HTTP_keepalive) to signal that the connection should be kept open for further messages (by default for *HTTP 1.1*). **Most sites are HTTP 1.1 compliant** now, - **Follow Redirects**: generates only a single HTTP Request when multiple [HTTP redirections](https://en.wikipedia.org/wiki/URL_redirection) are detected, and enables *Follow Redirects* on it. ![JMeter Recorder Request Filtering](https://blog.octoperf.com/img/blog/jmeter-recording/jmeter-recorder-request-filtering.png "JMeter Recorder Request Filtering") In addition to general settings, the recorder offers the ability to **filter requests**. How does it work? Based on *inclusion* and *exclusion* patterns, the **recorder chooses** if a request must be stored during the record or not. **What are filters for**? Mostly for filtering out resources like images, [CSS Stylesheets](https://www.w3.org/TR/html401/present/styles.html) and/or [Javascript](https://www.w3schools.com/js/js_whereto.asp) files. But, **that's not mandatory**. In fact, **it may be less realistic** to filter those resources since they are part of the application anyway. It's time to **record http requests** using JMeter's Proxy! ## HTTPS Setup **Recording HTTPS websites requires a bit more work** than plain HTTP websites. Let's see why. Let's start JMeter's Proxy Recorder: - Select `HTTP(s) Test Script Recorder` within the tree on the left, - Click on `Start` button: a dialog should show up asking to install [CA Root Certificate](https://en.wikipedia.org/wiki/Root_certificate). This certificate must be installed within the web browser to **support recording HTTPs traffic**. ![Root Certificate Dialog](https://blog.octoperf.com/img/blog/jmeter-recording/root-certificate-dialog.png "Root Certificate Dialog") **It may look complex at first glance**, but don't worry. Let me explain why you see this. ### Root Certificate Authority [TLS/SSL](https://en.wikipedia.org/wiki/Transport_Layer_Security) (The *S* in `HTTPS`) guarantees that there are **no spies between you and the server** you are contacting (no proxies). Normally, you use an `HTTP CONNECT` to open up a `TCP` connection through the *proxy*. In this case, the proxy will not be able to decrypt the traffic and **directly tunnel you** to the remote server. If **you want the proxy to decrypt HTTPS Traffic**, you need to take the following approach: - Client starts an `HTTPS` session, - Proxy transparently intercepts the connection and returns a generated (and weak) [SSL certificate](https://www.instantssl.com/ssl-certificate.html), signed by a CA ([Certificate Authority](https://en.wikipedia.org/wiki/Certificate_authority)) that is unconditionally trusted by the client, (we'll see how) - Proxy starts an `HTTPS` session to target, - Proxy verifies integrity of **SSL certificate**; failing if the certificate is invalid, - Finally, Proxy streams content, decrypts it and re-encrypts it with intermediate certificate. That's known as [MITM Attack](https://en.wikipedia.org/wiki/Man-in-the-middle_attack). ![MITM Attack](https://blog.octoperf.com/img/blog/jmeter-recording/mitm-attack.jpg "JMeter's Proxy is based on Man-In-The-Middle Attack to decrypt HTTPS Traffic") Said otherwise, we need to **install and trust JMeter's Root Certificate** to allow JMeter's Proxy **to decrypt HTTPS traffic**. Trust me, there is no risk unless you leak the Root certificate to a malicious third party. ![JMeter's Certificate Authority](https://blog.octoperf.com/img/blog/jmeter-recording/jmeter-root-certificate.png "JMeter's SSL Certificate Authority") JMeter generates a *Root Certificate Authority* within the `/bin` folder. You should find a file named `ApacheJMeterTemporaryRootCA.crt` in this folder. Let's see **how to install it in common web browsers**. ### Root CA Validity By default, JMeter generates a `Root CA valid only 7 days`. **That's annoying** since we need to redo the procedures below every week. But, there is a way to hack this. Open `/bin/jmeter.properties` and locate the following lines: ``` # The default validity for certificates created by JMeter #proxy.cert.validity=7 ``` For example, to have certificates valid for a year, change it to: ``` # The default validity for certificates created by JMeter proxy.cert.validity=365 ``` Remember to: - Stop JMeter, - Change the `jmeter.properties`, - Delete any existing ` / bin / ApacheJMeterTemporaryRootCA.crt`, - And restart JMeter. That should save you from repeating the **browser installation procedures** below too often. ### Firefox Setup To install JMeter's *Trusted Root Certificate Authority* in **Firefox**: - Open Firefox, ![Firefox Menu](https://blog.octoperf.com/img/blog/jmeter-recording/firefox-menu.png) - Open main menu and select `Preferences`, ![Firefox Prefs Menu](https://blog.octoperf.com/img/blog/jmeter-recording/firefox-prefs-menu.png) - Select `Privacy & Security` settings and scroll-down to the bottom of the page, ![Firefox Privacy Settings](https://blog.octoperf.com/img/blog/jmeter-recording/firefox-privacy-settings.png) - Click on `View Certificates` then click on `Import`, ![Firefox Certificates](https://blog.octoperf.com/img/blog/jmeter-recording/firefox-certificates.png) - Select the `ApacheJMeterTemporaryRootCA.crt` located in `/bin` folder. (`` is where JMeter is installed), ![Firefox Trust Certificate](https://blog.octoperf.com/img/blog/jmeter-recording/firefox-trust-certificate.png) - You should see the certificate within the *Certificate Manager*. ![JMeter Root CA Installed in Firefox](https://blog.octoperf.com/img/blog/jmeter-recording/firefox-certificate-installed.png) That's it! It should take you only a few minutes to install it. ### Google Chrome Setup Let's see now how to install JMeter's *Trusted Root Certificate Authority* in **Google Chrome**: - Open Google Chrome, - Click on main `menu`, ![Chrome Menu](https://blog.octoperf.com/img/blog/jmeter-recording/chrome-menu.png) - Then click on `Settings`, ![Chrome Menu](https://blog.octoperf.com/img/blog/jmeter-recording/chrome-settings-menu.png) - In the search field, enter `privacy` and scroll down to `Manage Certificates`, ![Chrome Privacy Settings](https://blog.octoperf.com/img/blog/jmeter-recording/chrome-privacy-settings.png) - Click on `Authorities`, then click on `Import`, - Select the `ApacheJMeterTemporaryRootCA.crt` located in `/bin` folder. (`` is where JMeter is installed), ![Chrome Import Authorities](https://blog.octoperf.com/img/blog/jmeter-recording/chrome-import-authorities.png) - Check `Trust this certificate for identifying websites`, ![Chrome Trust Certificate](https://blog.octoperf.com/img/blog/jmeter-recording/chrome-trust-certificate.png) - Finally, you should see JMeter's Root Certificate Authority installed. ![Chrome Certificate Install](https://blog.octoperf.com/img/blog/jmeter-recording/chrome-certificate-installed.png) That required quite a bit of work to compile! But we have **fully working HTTPS Recording** in both web browsers. Now, we're ready to **configure those browsers with JMeter's Proxy settings**. ## Proxy Setup ### Firefox Setup To configure JMeter's *Proxy* in **Firefox**: - Open Firefox, ![Firefox Menu](https://blog.octoperf.com/img/blog/jmeter-recording/firefox-menu.png) - Open main menu and select `Preferences`, ![Firefox Prefs Menu](https://blog.octoperf.com/img/blog/jmeter-recording/firefox-prefs-menu.png) - Select `General` section, then scroll-down to `Network Proxy`, ![Firefox General Menu](https://blog.octoperf.com/img/blog/jmeter-recording/firefox-proxy-settings.png) - Finally enter both *http* and *https* proxies with hostname `localhost` and port `8888` (default proxy port). ![Firefox Proxy Settings](https://blog.octoperf.com/img/blog/jmeter-recording/firefox-proxy-settings-set.png) - Click on `OK`. Firefox is now configured with JMeter's proxy settings and ready to record `http` and `https` requests. ### Google Chrome Setup To configure JMeter's *Proxy* in **Google Chrome**: - Open Google Chrome, - Click on main `menu`, ![Chrome Menu](https://blog.octoperf.com/img/blog/jmeter-recording/chrome-menu.png) - Then click on `Settings`, ![Chrome Menu](https://blog.octoperf.com/img/blog/jmeter-recording/chrome-settings-menu.png) - Enter `proxy` and select `Open Proxy Settings`. It should open system wide proxy settings. (depends on operating system) ![Chrome Menu](https://blog.octoperf.com/img/blog/jmeter-recording/chrome-proxy-settings.png) - Finally enter both *http* and *https* proxies with hostname `localhost` and port `8888` (default proxy port). Just beware that setting system wide proxy settings affects all applications sensitive to those settings (not just web browsers). ## Recording The Scenario We're finally reaching the most entertaining part of the tutorial: **recording the script**! If you're still there (and I won't mind if you're already sleeping), let's try to record [HTTPBin](https://httpbin.org). ![JMeter Start Recording](https://blog.octoperf.com/img/blog/jmeter-recording/jmeter-start-recording.png) Click on the `Start` button within the *HTTP(S) Test Script Recorder* to start JMeter's proxy. Click on `OK` when the Root CA dialog appears as see previously. In this example, we'll use *Firefox* because its proxy settings are confined. ![Firefox Proxy Issue](https://blog.octoperf.com/img/blog/jmeter-recording/firefox-proxy-issue.png) If you ever see the message `The proxy is refusing connections` within Firefox, please check: - You have started the *HTTP(S) Test Script Recorder* by clicking on `Start` button, - That proxy settings are properly set to the appropriate `hostname` and `port`. It usually boils down to the points described above. ![Firefox HTTPBin](https://blog.octoperf.com/img/blog/jmeter-recording/firefox-httpbin.png) Now browse to [https://httpbin.io](https://httpbin.io/). You should see requests filling in within the **Recording Controller**. ![JMeter HTTPBin Recording](https://blog.octoperf.com/img/blog/jmeter-recording/jmeter-httpbin-recording.png) Congratulations! You've just **recorded an SSL protected website using JMeter**. Once you are finished, go back to JMeter's Recorder, and click on `Stop` to stop the recording. Remember **proxy settings are still set within Firefox**. Any attempt to browse while JMeter's proxy is stopped / not running will result in the `The proxy is refusing connections` error. ## Additional resources In case you find JMeter recording too cumbersome, you may want to use the [HAR import feature of OctoPerf to get there](https://blog.octoperf.com/jmeter-vs-octoperf/). It's available even with a free account and you can export your script back as a JMX anytime. After recording it's also time to **rework the recorded script** like explained in our [JMeter REST API Testing](https://blog.octoperf.com/rest-api-testing-with-jmeter-step-by-step-guide/) guide: - Handling dynamic parameters, - making the script more realistic and random, - etc. You're **new to JMeter**? No worries. We have cooked a [JMeter Tutorial](https://blog.octoperf.com/jmeter-tutorial-for-beginners/) for beginners too.