Why does Jetty consume more threads than specified in start.ini file?
Problem Description:
I have my java spring application running inside Jetty 9.48.
These are the properties in start.ini file:
jetty.http.acceptors=30
# jetty.http.selectors=200
jetty.threadPool.minThreads=200
jetty.threadPool.maxThreads=1000
jetty.threadPool.idleTimeout=5000
jetty.http.host=0.0.0.0
jetty.http.port=8080
jetty.http.connectTimeout=2000
jetty.http.reuseAddress=true
jetty.lowresources.accepting=false
jetty.output.buffer.size=32768
jetty.httpConfig.outputAggregationSize=32768
jetty.httpConfig.requestHeaderSize=16384
jetty.httpConfig.responseHeaderSize=16384
jetty.httpConfig.sendServerVersion=false
jetty.httpConfig.sendDateHeader=false
jetty.server.stopAtShutdown=true
jetty.server.stopTimeout=5000
jetty.server.dumpAfterStart=false
jetty.server.dumpBeforeStop=false
jetty.deploy.scanInterval=0
jetty.console-capture.dir=/yyyy_mm_dd.stderrout.log
jetty.console-capture.retainDays=90
jetty.console-capture.timezone=UTC
jetty.debug.retainDays=90
When i run htop i see: "Tasks: 83, 3030 thr, 41 running".
And ps hUH p <JETTY PROCESS PID> | wc -l gives me 2876 jetty threads count.
Is it correct to compare these numbers with jetty.threadPool.maxThreads? If so, why maxThreads doesn’t limit number of threads? And why there is such a big gap between existing and running threads?
To be clear, i expect Jetty to consume less memory. I assumed that huge amount of threads can affect it. Because at the moment jetty consumes almost all available memory (120/125G) but OOM is never happens.
I may not understand some of the basic concepts, but I would be grateful if you could help me figure it out.
Solution – 1
Jetty 9.x is now at End of Community Support (soon to be End of Life)
See: https://github.com/eclipse/jetty.project/issues/7958
You are not paying attention to what those threads are.
Jetty threads will have a name that start with qtp.
All other threads are from things that are not Jetty.