Selenium Grid, running multiple browser instances in parallel

Question

I'm using Selenium grid to run multiple instances of my test in parallel. I want to test if I can run a lot of browsers at the same time. My problem is that I can't have more that 5 five browsers at the same time, and I don't know why.

Here are the commands I'm using to start the hub and the node:

java -jar %seleniumPath% -port 4444 -role hub -nodeTimeout 1000

java -jar %seleniumPath% -role node -hub http://localhost:4444/grid/register -browser browserName=firefox,maxInstances=1,maxSession=1 -port 5555

NOTE: The two commands are working but what I don't understand are the maxInstances and the maxSession arguments. I set them to 1 but I can still run more than one browser and if I set them to 10 or more only 5 browsers will run at the same time.

What should I do to have more than 5 browsers running at the same time?

Answer 1

Generally, according to Selenium Grid2 official documentation , -maxSession is the maximum number of browsers that can run in parallel on the node while -maxInstances sets how many instances of a particular browser can run simultaneously.

Don't forget to restart the local java process responsible for node session on each remote machine to apply these settings.