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tomcatniotomcat9apr

Fastest connection for tomcat 9.0 in 2021: NIO or APR?

I'm installing a server that's going to be mostly transferring files over 16MiB, and upload/download speed for individual transfers will be essential, but no more than say 100 connections at once. We have a backend that uses a custom UDP connection, but the failover is to HTTP/TCP so I want to make sure that's fast too

The web server is Apache Tomcat 9.0 and I've installed the APR library so my SSL connector in $CATALINA_HOME/conf/server.xml is working with either
protocol="org.apache.coyote.http11.Http11NioProtocol"
or
protocol="org.apache.coyote.http11.Http11AprProtocol"
and then
<UpgradeProtocol className="org.apache.coyote.http2.Http2Protocol" />

But I'm finding conflicting information online about which is a better choice on something like Tomcat 9.0.52. It's running in a Debian 11 VM if that changes anything.

This seems to be related Tomcat with APR still says aprConnector is false

Solution

  • When using HTTPS you actually have 5 choices: NIO+JSSE, NIO+OpenSSL, NIO2+JSSE, NIO2+OpenSSL, APR+OpenSSL.

    From a presentation by Jean-Frederic Clere at ApacheCon 2017 you can see that:

    • OpenSSL beats JSSE by an order of magnitude,
    • NIO vs NIO2 vs APR performance is very similar, but Java implementations usually end up on top.

    Since the default configuration of the AprLifecycleListener is equivalent to:

    <Listener SSLEngine="on" FIPSMode="off" SSLRandomSeed="builtin"
          useAprConnector="false" useOpenSSL="true"
          className="org.apache.catalina.core.AprLifecycleListener"/>

    you'll get NIO+OpenSSL by default whenever the Tomcat Native Library is detected in your system.