Can we run multiple instances simultaneously with Selenium WebDriver

Question

I'm trying to use Selenium to automate file uploading and I've already written a program with Selenium WebDriver that works. The problem is, there are thousands of files which need to be uploaded, I'd like to run multiple browser instances simultaneously to speed up the automation. So I tried something like this:

upload i = 0;
while (i < 10) {
    i++;
    upload driver = new webdriver.Builder()
            .forBrowser('firefox')
            .build();

    // login and upload files......
}

While I expected this to create 10 browser instances simultaneously, and upload it parallelly, the above code actually creates browser instance 'one by one' which means, it won't create another instance until the previous one finishes. I'v also tried executing the program in multiple shell instances, that will fire up multiple browser instances for me, but it doesn't work...

Answer 1

A better option is to create multiple threads instead of looping. You can start each upload in parallel threads instead of using selenium grid to achieve this.
You need to learn how multithreading works though.

It's not right to use grid for executing in multiple browsers parallelly. You can invoke multiple browser sessions by just creating multiple driver objects, and managing them. Each session will be separate if you want them to be. If you try executing with multiple browsers, then the performance of the system will be hampered.

Grid is preferrable only if you want to execute on remote machines and when the no. of parallel tests are in excess of 10 tests.

Comments

how do i synchronize in multiple instances?

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Have a look at https://www.edureka.co/blog/selenium-grid-tutorial

Hope this helps!