I am using Selenium grid to scrape thousands of pages since all the pages are heavily populated by Javascript.
I found this tutorial which gave me a pretty good idea of how to set up Selenium grid and run script in parallel. However, my situation is a little different.
(1) I only want one type of browser, like Chrome(or Firefox), but I want to run as many as possible.
(2) To make sure this solution scale, I probably will use some Cloud service where the code will be running in Linux environment.
So here is my question:
Do I have to use TestNG/Junit frame work to run the code in parallel? If I run the code in multiple processes, all making requests to the same hub, will the hub coordinate them out of box?
(1) I only want one type of browser, like Chrome(or Firefox), but I
want to run as many as possible.
You should be running not as many possible, but a heuristic number, that just works for you. The reason being is, running like 30 chrome browsers at a time can give you unpredictable results.
(2) To make sure this solution scale, I probably will use some Cloud
service where the code will be running in Linux environment.
You can look at BrowserStack
Do I have to use TestNG/Junit frame work to run the code in parallel?
Thats upto you. As far as your creating the driver in multiple threads your fine. If your using your own FW, then you can create Thread pool and start creating the driver from each thread pool.
If I run the code in multiple processes, all making requests to the
same hub, will the hub coordinate them out of box?
Yes Selenium Hub will be co-ordinating this for you, out of the box. You no need to worry about anything here.
Related
I am trying to build an instagram bot with selenium. So far I have managed to get it work with 1 chrome window and 1 account, it auto follows, likes etc. with the given http requests on my express server. However when I try it with 2 different accounts on 2 different selenium instances or windows, the first one stops executing the function(or maybe it starts executing on the second chrome window, I dont know whats happening). So can anyone explain me if and how its possible to continue execution on multiple windows? Note: I don't want to switch between instances.
You can use the Selenium Grid to implement the scenario.
Generally, Hub & Node Structure is generally used to run parallel Tests.
https://www.guru99.com/introduction-to-selenium-grid.html
Above link will help you to get the concept of Grid.
I have a large suite of SpecFlow tests executing against a selenium grid running locally. The grid has a single host configured for max 10 firefox instances. The tests are run from NUnit serially, so I would only expect to require a single session at a time.
However, when approximately half of the test cases have been run, the console window reporting output from the hub starts reporting
INFO: Node host [url] has no free slots
Why?
All the test cases are associated with a TearDown method that closes and disposes the WebDriver, although I haven't verified that absolutely every test gets to this method without failing. I would expect a maximum of one session to be active at once. How can I find out what is stopping the host from recycling those sessions?
edit #1:
I think I've narrowed down the cause of the issue - it is indeed to do with not closing the WebDriver. There are [AfterScenario] attributes on the teardown methods that are meant to do this, but they only match a subset of scenarios as they have parameters on them. Removing the parameter so that the teardown associates with every scenario fixes the session exhaustion (or seems to) but there are some tests that expect to reacquire an existing session, so I'll have to fix them separately.
A bit of background: This test suite was inherited as part of a 'complete' solution and it's been left untouched and never run since delivery. I'm putting it back into service and have had to discover its quirks as I go - I didn't write any of this. I've had brief encounters with both Selenium and SpecFlow but never used the two together.
The issue turned out to be a facepalm-level fail - mostly in the sense that I didn't spot it. Some logging code was trying to write to a file that wasn't there, the thrown exception bypassed the call to Dispose() on the WebDriver, and was then swallowed with no error reporting. Therefore the sessions were hanging around. Removing the logging code fixed the session exhaustion.
Look on the node (remote desktop) and see what is happening on the box. It does sound like your test isn't closing out it's session properly.
I'm trying to simulate a firefox load testing situation. I want my to test how 10 simultaneous logins would play out on my system. I already have a connected selenium grid hub and 10 open nodes.
So far, I know I can write the test case and run it 10 times which isn't what I need because it isn't automated. I also know that I can use invocation count on the test to make it run as many times as i want but this only works on the same browser node.
Does anyone have any ideas on how to automatically distribute the same test case to multiple instances of the same driver profile?
i.e. Run a login case test times on the same firefox profile open in 10 different nodes in parallel.
Gracias!
P.S. I built my tests using testNG if that matters.
Basically selenium and testNG is not for such requiurement. You should use some dedicated tool for that like jmeter.
However you can run n methods parrallel let say if you want to login with 10 dif user in 10 thread/browser you can create test data driven and configure to run method in parrallel. Make sure you are providing proper value of parrallel thread count.
How about combining threadpoolsize with invocationcount. - http://testng.org/doc/documentation-main.html#parallel-running
Grid would take care to distribute on the 10 nodes.
use headless browser like GHOST and then invoke multiple threads as ghost has no UI so it would work in your case
I have multiple similar sites (same layout, just different data), and each of them has drop down menu on mouse over (and disappears on mouse out).
I am using Selenium 2 and WebDriver, and I have one selenium test case that basically do the mouse over and make sure each of the link in the drop down menu works.
I am using selenium grid, so I have a hub and few test machines.
Because I have many sites (few hundred) to test, so I am thinking of making each machine to run the test case against multiple sites in parallel.
My concern is because there can be only one active browser at a time, will it cause issue if web driver tries to perform Action.moveToElement() on multiple browsers at roughly the same time? Will only the active browser performs Action.moveToElement() properly and other browsers fail? If there will be an issue, is there any workaround?
I have tried it using JUnitCore.runClasses(ParallelComputer.classes(), SomeClass1.class, SomeClass2.class, SomeClass3.class);, it decreased the passed tests percentage from 100% to about 67% when running three tests on a machine. Not good =/.
The good part - firefox actually can do it in parallel. If the FF instances are delayed between each other so they don't do the same thing at the same time, it works better. Some of the failures happened during a Firefox bootup - so if you can minimize closing and opening windows, do it. But still, sometimes it just fails for no reason.
If you really would use the saved time, then go for it, log all failed tests and run them again after the first round - this time one at a time.
You could also solve this, depending on your ultimate goal of testing, by not using the Action class with the mouse-movement click, but instead use the WebDriver findBy-click method or Javascript executor method. It would probably be less contentious when running multiple windows at the same time. If the Action class, when defining a mouse movement, uses native calls at all, such as "move to Point", then one browser over the top of another, then I would guess it's possible that the movement point could be masked by another window. I am really not sure about this, just giving you another idea to try.
I'd like to run tests that simulate users modifying certain data at the same time for a grails application.
Are there any plug-ins / tools / mechanisms I can use to do this efficiently? They don't have to be grails specific. It should be possible to fire multiple actions in parallel.
I'd prefer to run the tests on functional level (so far I'm using Selenium for other tests) to see the results from the user perspective. Of course this can be done in addition to integration testing if you'd recommend to run concurrent modification tests on integration level as well.
I have used Geb (http://grails.org/plugin/geb/) for this recently. It is a layer on top of WebDriver and Selenium etc.. Its very easy to write a Grails script to act as a user in your app and then just run several instances on different consoles. Geb uses a jQuery style syntax for locating stuff in the DOM which is very cool:
import geb.Browser
import geb.Configuration
includeTargets << grailsScript("_GrailsInit")
target(main: "Do stuff as fast as possible") {
Configuration cfg = new Configuration(baseUrl: "http://localhost:8080/your_app/")
Browser.drive(cfg) {
go "user/login"
$("#login form").with {
email = "someone#somewhere.com"
password = "secret"
_action_Login().click()
}
...
}
}
setDefaultTarget(main)
Just put your script in scripts/YourScript.groovy and then you can do "Grails YourScript" to run it. I tracked down some concurrency issues by just running several of these at full speed. You do need to build a war and deploy it properly as Grails in dev mode is very slow and runs out of permgen space quite quickly.
Just an idea: it seems difficult to make client starts at the same time, but can they wait for each other just before modifying data?
Such as, a client keeps logging its process: "Client x access DATA", "Client x editing DATA" in a file. They also keep looking this log file, to see other clients' progress. Then don't permit a client complete editing a DATA until another client comes in to edit that DATA.
I've found Grinder to be an excellent tool for heavy load testing. Running multiple instances performing the same tests at one time can often uncover concurrency issues in your app that you wouldn't find with normal tests.
If you want to do this within Unit Tests or in-code Integration Tests, you could always spin up multiple threads in code and have them perform the task you're trying to test.
Are you primarily interested in load testing multiple active users, as opposed to those who just have a HttpSession? Solid load testing is predicated on really really good func. testing however. How are your functional tests organized and executed to-day? Grails has a plug-in* for that, too, and it appears to be in the Top of the Pops at the plug-in portal.
Are you attempting to test out how the optimistic locking mechanism performs under load?
If the former use case is the one that means more, it sounds like you may be looking for JUnitPerf. Here is the --> download
*functional-test <1.2.7> -- Functional Testing
WebTest is built on Ant which provides the parallel task. You might be able to use this in conjuction with the Webtest plugin to run some actions in parallel. I've never tried it though.
Have a look at MultithreadedTC. It looks like it could be used to exercise certain interleaving cases where multiple threads are executing your code in ways you consider potentially risky.
I doubt you'll find a convenient way to test specific multithreaded interleaving cases with Selenium because Selenium controls a browser which sends requests to your server. I haven't heard of a way to instrument code for multithreaded interleaving tests when the threads are started as real web requests to a running web server.