Scaling and Managing Selenium Grid

Dima Kovalenko@dimacus

• Note to self, this slide should be completely blank, NO TEXT of any sort!

Shameless Plug

ISBN: 9781783982707https://www.packtpub.com/web-development/selenium-design-patterns-and-best-practices

Explaining Grid

• Dumb Nodes

Explaining Grid

• Dumb Nodes• Even Dumber Hub

Hub is a Glorified Proxy Server

• HUB is an HTTP Proxy• That tracks node count– Does not know much else about nodes

Getting Priorities Right

• Stability• Speed• Coverage

Stability

• Become a Sys Admin

Stability

• Become a Sys Admin• Move as much to Linux as possible

Stability

• Become a Sys Admin• Move as much to Linux as possible• Only 1 test at the time!

- At least for IE Safari

Stability

• Become a Sys Admin• Move as much to Linux as possible• Only 1 test at the time!

- Shared resources at OS level

Stability

• Become a Sys Admin• Move as much to Linux as possible• Only 1 test at the time!• Configuration as code– Git– Chef– Puppet

Configuration Management

• Node Configs– Grid Hub Configs– Grid Node Configs– Store In Git

Configuration Management

• Node Configs– Grid Hub Configs– Grid Node Configs– Store In Git

• OS Configs– Crons– Versions

• Browsers• Java• Etc..

Speed

• Smaller Nodes– Better to have 10 computers with 1 browser

• It’s ok to use low end machines

Speed

• Smaller Nodes– Better to have 10 computers with 1 browser

• It’s ok to use low end machines– Take performance hit in place of faster run time

Coverage

• Can we add IE6 and 7 to the Grid?

Coverage

Coverage

• More maintenance• IE8 takes 50% of free time

• IE9 or > is much Safer to use

International Buy Jim Evans a BEER day!

International Buy Jim Evans a BEER day!

International Buy Jim Evans a BEER day!

More On Stability

• Don’t Use RC– java -jar selenium.jar -role node

More On Stability

• Don’t Use RC• Use WebDriver–java -jar selenium.jar -role wd

More On Stability

• Replace Internet Explorer with Batch file• Create Crons (Scheduled Tasks)– Periodically Restart Grid node (JAR)– Periodically Restart Computer

More On Stability

• Replace Internet Explorer with Batch file– Cleans up Cookies, Cache, etc– Launches Internet Explorere

More On Stability

• Replace Internet Explorer with Batch file• Create Crons (Scheduled Tasks)• Auto login & Auto Start at login– Always auto login with the Build User

More On Stability

• Replace Internet Explorer with Batch file• Create Crons (Scheduled Tasks)• Auto login & Auto Start at login• Etc.. Etc.. Etc..

Selenium Grid Extras

• 1 year old

Selenium Grid Extras

• https://github.com/groupon/Selenium-Grid-Extras

Goal of the Project

• Document Grid Stability with code

Goal of the Project

• Document Grid Stability with code– (Poorly written Java code that is)

• Make the setup and maintenance of the grid simple

Features to improve stability

• Automatically Set IE Protected Security Zone each reboot

• Move the mouse out of the way• Kill web browser after Test• Kill chromedriver.exe and iedriver.exe after

build• Automatically update Drivers and JARS• Store config for all nodes in single place

Latest Features

• Restart node every X builds, when node is free• Jenkins Plugin• Video recording of test (Work in progress)

Optionally Reboot OS

• Windows reboot not optional!• Improves speed and test stability• Prevents this:

Video Recording

• (Work in Progress)

Demo

Jenkins Plugin

• (Work in Progress)

Find IE Crashes at a Glance

Questions?