Jmeter Cookie manager impact of AWS sticky sessions

0
votes

I have created a Jmeter script to check the performance of a site. The website is hosted in AWS with elastic scaling and with sticky sessions. Basically the AWS load balancer will assign a session cookie to each user so the load balancer can direct the user to the correct instance.

enter image description here source

My problem is, as I'm using a cookie manager and clearing all the cookies with each iteration. Does it clear these assigned cookies too? I suspect this because the script error rate is lower when we execute the script on a single AWS instance than in auto-scaling ( multiple instances )

Any idea ?

2
amazon-web-servicessessionjmeterautoscalingcookiemanager

2 Answers

1
votes

I don't know about how do you "clear" cookies, if you use this box of the HTTP Cookie Manager:

enter image description here

then it removes all cookies on each new iteration of the Thread Group (other loop generation options like Loop Controller or While Controller will not trigger clearing of cookies)

Also if your Load Balancer has more that one IP address you might want to add the DNS Cache Manager to your Test Plan in order to avoid DNS requests caching on JVM or OS side.

0
votes

The problem was not with the JMeter script. It's with the AWS ELB in a elastic server config. We had configured a Alarm to remove the instance from load balancer, so even with the stickey sessions enabled when the instance is removed it generated the error. After moving the session managemet to a Elasticache - Redid based solution, this issue will be fixed.

Thank you all who supported.