Selenium lagging when opening more sessions











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I am using VPS with 8 CPU cores.



Problem started when I opened around 30 sessions of Chrome web driver. I minimized all browsers to reduce CPU usage and I was tracking tests inside my prompt.
Usually 1 test lasts 55 seconds, but when I have more sessions they vary from 1 minute to 3 minutes sometimes. What is cause of the problem here? My CPU usage is around 20 percent of all time.










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  • Have you tried adding chrome_options? you can use '--headless' like this chrome_options.add_argument('--headless')
    – Moshe Slavin
    Nov 22 at 10:52










  • I did, tests work great then but the problem is CPU usage. I can't handle more then 5 headless chromes and my VPS is pretty strong.
    – Mark Letterman
    Nov 22 at 10:57










  • Do all the 30 sessions need to run in parallel?
    – Moshe Slavin
    Nov 22 at 10:59










  • Yes they do. It is crucial for me that tests run in period of 55 seconds - 1 minute max.
    – Mark Letterman
    Nov 22 at 11:05















up vote
2
down vote

favorite












I am using VPS with 8 CPU cores.



Problem started when I opened around 30 sessions of Chrome web driver. I minimized all browsers to reduce CPU usage and I was tracking tests inside my prompt.
Usually 1 test lasts 55 seconds, but when I have more sessions they vary from 1 minute to 3 minutes sometimes. What is cause of the problem here? My CPU usage is around 20 percent of all time.










share|improve this question






















  • Have you tried adding chrome_options? you can use '--headless' like this chrome_options.add_argument('--headless')
    – Moshe Slavin
    Nov 22 at 10:52










  • I did, tests work great then but the problem is CPU usage. I can't handle more then 5 headless chromes and my VPS is pretty strong.
    – Mark Letterman
    Nov 22 at 10:57










  • Do all the 30 sessions need to run in parallel?
    – Moshe Slavin
    Nov 22 at 10:59










  • Yes they do. It is crucial for me that tests run in period of 55 seconds - 1 minute max.
    – Mark Letterman
    Nov 22 at 11:05













up vote
2
down vote

favorite









up vote
2
down vote

favorite











I am using VPS with 8 CPU cores.



Problem started when I opened around 30 sessions of Chrome web driver. I minimized all browsers to reduce CPU usage and I was tracking tests inside my prompt.
Usually 1 test lasts 55 seconds, but when I have more sessions they vary from 1 minute to 3 minutes sometimes. What is cause of the problem here? My CPU usage is around 20 percent of all time.










share|improve this question













I am using VPS with 8 CPU cores.



Problem started when I opened around 30 sessions of Chrome web driver. I minimized all browsers to reduce CPU usage and I was tracking tests inside my prompt.
Usually 1 test lasts 55 seconds, but when I have more sessions they vary from 1 minute to 3 minutes sometimes. What is cause of the problem here? My CPU usage is around 20 percent of all time.







python selenium web selenium-webdriver driver






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share|improve this question




share|improve this question










asked Nov 22 at 9:38









Mark Letterman

161




161












  • Have you tried adding chrome_options? you can use '--headless' like this chrome_options.add_argument('--headless')
    – Moshe Slavin
    Nov 22 at 10:52










  • I did, tests work great then but the problem is CPU usage. I can't handle more then 5 headless chromes and my VPS is pretty strong.
    – Mark Letterman
    Nov 22 at 10:57










  • Do all the 30 sessions need to run in parallel?
    – Moshe Slavin
    Nov 22 at 10:59










  • Yes they do. It is crucial for me that tests run in period of 55 seconds - 1 minute max.
    – Mark Letterman
    Nov 22 at 11:05


















  • Have you tried adding chrome_options? you can use '--headless' like this chrome_options.add_argument('--headless')
    – Moshe Slavin
    Nov 22 at 10:52










  • I did, tests work great then but the problem is CPU usage. I can't handle more then 5 headless chromes and my VPS is pretty strong.
    – Mark Letterman
    Nov 22 at 10:57










  • Do all the 30 sessions need to run in parallel?
    – Moshe Slavin
    Nov 22 at 10:59










  • Yes they do. It is crucial for me that tests run in period of 55 seconds - 1 minute max.
    – Mark Letterman
    Nov 22 at 11:05
















Have you tried adding chrome_options? you can use '--headless' like this chrome_options.add_argument('--headless')
– Moshe Slavin
Nov 22 at 10:52




Have you tried adding chrome_options? you can use '--headless' like this chrome_options.add_argument('--headless')
– Moshe Slavin
Nov 22 at 10:52












I did, tests work great then but the problem is CPU usage. I can't handle more then 5 headless chromes and my VPS is pretty strong.
– Mark Letterman
Nov 22 at 10:57




I did, tests work great then but the problem is CPU usage. I can't handle more then 5 headless chromes and my VPS is pretty strong.
– Mark Letterman
Nov 22 at 10:57












Do all the 30 sessions need to run in parallel?
– Moshe Slavin
Nov 22 at 10:59




Do all the 30 sessions need to run in parallel?
– Moshe Slavin
Nov 22 at 10:59












Yes they do. It is crucial for me that tests run in period of 55 seconds - 1 minute max.
– Mark Letterman
Nov 22 at 11:05




Yes they do. It is crucial for me that tests run in period of 55 seconds - 1 minute max.
– Mark Letterman
Nov 22 at 11:05












1 Answer
1






active

oldest

votes

















up vote
1
down vote













The cause of the problem most probably is RAM usage. For browser execution RAM is crucial and when you got to the limit, the tests start to perform slower. Check out the usage of RAM and most likely you will see that 30 instances of a browser use it all.



As a suggestion play around the number of browsers and try to keep an optimal percentage of RAM usage. In your case maybe limiting the number of parallel threads to 25 or even 20 will make entire suite run faster than in 30. But of course, if there is an option it's better to just add more memory and proceed with fast automation ;)



some more details about FF and Chrome RAM usage



Edit after a comment that Ram is only used by 15%



It could simply be an app, that slows down under load. Yep, 30 threads do not look anyhow valuable but it may depend on the app-environment hardware or just that some part of an app's performance has an issue. We had a case when our tests were working fine on one environment in 200 threads, but when data center was migrating, we switched to different environments (that were configured differently) and we found that at the beginning the new environment only could normally work under 30-50 threads (comparing to usual 200). We reported it as an issue and it was confirmed and solved by IT team.



As a suggestion for this case - try to monitor when does the slowdown happen, is there any patterns for example - 'after 10 minutes of test suite run' or 'after some action on the app being called'. This info may help to investigate the potential problem on an app side.






share|improve this answer























  • I have 40gb of ram, and when i run tests, only 15% is used.
    – Mark Letterman
    Nov 22 at 22:47










  • @MarkLetterman updated my answer with a second suggestion as the RAM does not seem to be the case
    – Vladimir Efimov
    Nov 23 at 5:24










  • I noticed what is the problem that is causing lag. It is .sendkeys() command when i try to write something by finding element. This function is very slow on Chrome when is minimized. I wonder how can i speed it up?
    – Mark Letterman
    Nov 24 at 21:00










  • @MarkLetterman the only thing I can think of is replacing sendKeys method call with javascript. it should look something like WebElement el = ........; ((JavascriptExecutor) driver).executeScript("arguments[0].value='text you want to enter'", el)
    – Vladimir Efimov
    Nov 25 at 20:11













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1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes








up vote
1
down vote













The cause of the problem most probably is RAM usage. For browser execution RAM is crucial and when you got to the limit, the tests start to perform slower. Check out the usage of RAM and most likely you will see that 30 instances of a browser use it all.



As a suggestion play around the number of browsers and try to keep an optimal percentage of RAM usage. In your case maybe limiting the number of parallel threads to 25 or even 20 will make entire suite run faster than in 30. But of course, if there is an option it's better to just add more memory and proceed with fast automation ;)



some more details about FF and Chrome RAM usage



Edit after a comment that Ram is only used by 15%



It could simply be an app, that slows down under load. Yep, 30 threads do not look anyhow valuable but it may depend on the app-environment hardware or just that some part of an app's performance has an issue. We had a case when our tests were working fine on one environment in 200 threads, but when data center was migrating, we switched to different environments (that were configured differently) and we found that at the beginning the new environment only could normally work under 30-50 threads (comparing to usual 200). We reported it as an issue and it was confirmed and solved by IT team.



As a suggestion for this case - try to monitor when does the slowdown happen, is there any patterns for example - 'after 10 minutes of test suite run' or 'after some action on the app being called'. This info may help to investigate the potential problem on an app side.






share|improve this answer























  • I have 40gb of ram, and when i run tests, only 15% is used.
    – Mark Letterman
    Nov 22 at 22:47










  • @MarkLetterman updated my answer with a second suggestion as the RAM does not seem to be the case
    – Vladimir Efimov
    Nov 23 at 5:24










  • I noticed what is the problem that is causing lag. It is .sendkeys() command when i try to write something by finding element. This function is very slow on Chrome when is minimized. I wonder how can i speed it up?
    – Mark Letterman
    Nov 24 at 21:00










  • @MarkLetterman the only thing I can think of is replacing sendKeys method call with javascript. it should look something like WebElement el = ........; ((JavascriptExecutor) driver).executeScript("arguments[0].value='text you want to enter'", el)
    – Vladimir Efimov
    Nov 25 at 20:11

















up vote
1
down vote













The cause of the problem most probably is RAM usage. For browser execution RAM is crucial and when you got to the limit, the tests start to perform slower. Check out the usage of RAM and most likely you will see that 30 instances of a browser use it all.



As a suggestion play around the number of browsers and try to keep an optimal percentage of RAM usage. In your case maybe limiting the number of parallel threads to 25 or even 20 will make entire suite run faster than in 30. But of course, if there is an option it's better to just add more memory and proceed with fast automation ;)



some more details about FF and Chrome RAM usage



Edit after a comment that Ram is only used by 15%



It could simply be an app, that slows down under load. Yep, 30 threads do not look anyhow valuable but it may depend on the app-environment hardware or just that some part of an app's performance has an issue. We had a case when our tests were working fine on one environment in 200 threads, but when data center was migrating, we switched to different environments (that were configured differently) and we found that at the beginning the new environment only could normally work under 30-50 threads (comparing to usual 200). We reported it as an issue and it was confirmed and solved by IT team.



As a suggestion for this case - try to monitor when does the slowdown happen, is there any patterns for example - 'after 10 minutes of test suite run' or 'after some action on the app being called'. This info may help to investigate the potential problem on an app side.






share|improve this answer























  • I have 40gb of ram, and when i run tests, only 15% is used.
    – Mark Letterman
    Nov 22 at 22:47










  • @MarkLetterman updated my answer with a second suggestion as the RAM does not seem to be the case
    – Vladimir Efimov
    Nov 23 at 5:24










  • I noticed what is the problem that is causing lag. It is .sendkeys() command when i try to write something by finding element. This function is very slow on Chrome when is minimized. I wonder how can i speed it up?
    – Mark Letterman
    Nov 24 at 21:00










  • @MarkLetterman the only thing I can think of is replacing sendKeys method call with javascript. it should look something like WebElement el = ........; ((JavascriptExecutor) driver).executeScript("arguments[0].value='text you want to enter'", el)
    – Vladimir Efimov
    Nov 25 at 20:11















up vote
1
down vote










up vote
1
down vote









The cause of the problem most probably is RAM usage. For browser execution RAM is crucial and when you got to the limit, the tests start to perform slower. Check out the usage of RAM and most likely you will see that 30 instances of a browser use it all.



As a suggestion play around the number of browsers and try to keep an optimal percentage of RAM usage. In your case maybe limiting the number of parallel threads to 25 or even 20 will make entire suite run faster than in 30. But of course, if there is an option it's better to just add more memory and proceed with fast automation ;)



some more details about FF and Chrome RAM usage



Edit after a comment that Ram is only used by 15%



It could simply be an app, that slows down under load. Yep, 30 threads do not look anyhow valuable but it may depend on the app-environment hardware or just that some part of an app's performance has an issue. We had a case when our tests were working fine on one environment in 200 threads, but when data center was migrating, we switched to different environments (that were configured differently) and we found that at the beginning the new environment only could normally work under 30-50 threads (comparing to usual 200). We reported it as an issue and it was confirmed and solved by IT team.



As a suggestion for this case - try to monitor when does the slowdown happen, is there any patterns for example - 'after 10 minutes of test suite run' or 'after some action on the app being called'. This info may help to investigate the potential problem on an app side.






share|improve this answer














The cause of the problem most probably is RAM usage. For browser execution RAM is crucial and when you got to the limit, the tests start to perform slower. Check out the usage of RAM and most likely you will see that 30 instances of a browser use it all.



As a suggestion play around the number of browsers and try to keep an optimal percentage of RAM usage. In your case maybe limiting the number of parallel threads to 25 or even 20 will make entire suite run faster than in 30. But of course, if there is an option it's better to just add more memory and proceed with fast automation ;)



some more details about FF and Chrome RAM usage



Edit after a comment that Ram is only used by 15%



It could simply be an app, that slows down under load. Yep, 30 threads do not look anyhow valuable but it may depend on the app-environment hardware or just that some part of an app's performance has an issue. We had a case when our tests were working fine on one environment in 200 threads, but when data center was migrating, we switched to different environments (that were configured differently) and we found that at the beginning the new environment only could normally work under 30-50 threads (comparing to usual 200). We reported it as an issue and it was confirmed and solved by IT team.



As a suggestion for this case - try to monitor when does the slowdown happen, is there any patterns for example - 'after 10 minutes of test suite run' or 'after some action on the app being called'. This info may help to investigate the potential problem on an app side.







share|improve this answer














share|improve this answer



share|improve this answer








edited Nov 23 at 11:06

























answered Nov 22 at 15:43









Vladimir Efimov

655311




655311












  • I have 40gb of ram, and when i run tests, only 15% is used.
    – Mark Letterman
    Nov 22 at 22:47










  • @MarkLetterman updated my answer with a second suggestion as the RAM does not seem to be the case
    – Vladimir Efimov
    Nov 23 at 5:24










  • I noticed what is the problem that is causing lag. It is .sendkeys() command when i try to write something by finding element. This function is very slow on Chrome when is minimized. I wonder how can i speed it up?
    – Mark Letterman
    Nov 24 at 21:00










  • @MarkLetterman the only thing I can think of is replacing sendKeys method call with javascript. it should look something like WebElement el = ........; ((JavascriptExecutor) driver).executeScript("arguments[0].value='text you want to enter'", el)
    – Vladimir Efimov
    Nov 25 at 20:11




















  • I have 40gb of ram, and when i run tests, only 15% is used.
    – Mark Letterman
    Nov 22 at 22:47










  • @MarkLetterman updated my answer with a second suggestion as the RAM does not seem to be the case
    – Vladimir Efimov
    Nov 23 at 5:24










  • I noticed what is the problem that is causing lag. It is .sendkeys() command when i try to write something by finding element. This function is very slow on Chrome when is minimized. I wonder how can i speed it up?
    – Mark Letterman
    Nov 24 at 21:00










  • @MarkLetterman the only thing I can think of is replacing sendKeys method call with javascript. it should look something like WebElement el = ........; ((JavascriptExecutor) driver).executeScript("arguments[0].value='text you want to enter'", el)
    – Vladimir Efimov
    Nov 25 at 20:11


















I have 40gb of ram, and when i run tests, only 15% is used.
– Mark Letterman
Nov 22 at 22:47




I have 40gb of ram, and when i run tests, only 15% is used.
– Mark Letterman
Nov 22 at 22:47












@MarkLetterman updated my answer with a second suggestion as the RAM does not seem to be the case
– Vladimir Efimov
Nov 23 at 5:24




@MarkLetterman updated my answer with a second suggestion as the RAM does not seem to be the case
– Vladimir Efimov
Nov 23 at 5:24












I noticed what is the problem that is causing lag. It is .sendkeys() command when i try to write something by finding element. This function is very slow on Chrome when is minimized. I wonder how can i speed it up?
– Mark Letterman
Nov 24 at 21:00




I noticed what is the problem that is causing lag. It is .sendkeys() command when i try to write something by finding element. This function is very slow on Chrome when is minimized. I wonder how can i speed it up?
– Mark Letterman
Nov 24 at 21:00












@MarkLetterman the only thing I can think of is replacing sendKeys method call with javascript. it should look something like WebElement el = ........; ((JavascriptExecutor) driver).executeScript("arguments[0].value='text you want to enter'", el)
– Vladimir Efimov
Nov 25 at 20:11






@MarkLetterman the only thing I can think of is replacing sendKeys method call with javascript. it should look something like WebElement el = ........; ((JavascriptExecutor) driver).executeScript("arguments[0].value='text you want to enter'", el)
– Vladimir Efimov
Nov 25 at 20:11




















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