On 28/09/2020 17:58, Arshiya Shariff wrote: > Hi All, > With 200 threads(users) , ramp up duration of 2 seconds , loop count 80 and > by sending 1000 http2 requests/sec from JMeter Client to an embedded tomcat > application we did not observe any memory issue , but on sending 1000 http2 > requests/sec with 2000 or 1000 users from JMeter , the application's heap > space of 20 GB is occupied in 2 minutes and after 2 full GCs the memory > clears and comes down to 4GB (expected) . > > Embedded tomcat Version:9.0.38 > Max Threads : 200 > All other properties are the tomcat defaults. > > Why is tomcat not able to process many connections ?
You haven't provided any evidence that Tomcat isn't able to process "many" connections. > Why is the memory filled when the connections are increased, are there any > parameters to tune connections ? It looks like users == HTTP/2 Connection. Connections are required to maintain state for closed streams for both prioritisation and for error handling. More connections == more state == more memory. Given the number of connections increased by a factor of between 12.5 and 25, that the memory usage only increased by a factor of 5 looks to be a positive result rather than an issue. There are significant improvements to memory usage in this area in Tomcat 10.0.x that will get back-ported to 9.0.x but more testing is required. Are you able to test with a custom Tomcat build and/or build Tomcat 9 from source for testing? Mark --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
