The lost async servlets

[zloster]

Work toward their restoration. See issue 2598 in the upstream repository.

[zloster]

These will be left for later:

• https://github.com/TechEmpower/FrameworkBenchmarks/blob/70b3d1adc59a9e53d23b569554466576186480c6/frameworks/Java/servlet3-cass/src/main/java/fi/markoa/tfb/servlet3/MessageDAOCassImpl.java
• https://github.com/TechEmpower/FrameworkBenchmarks/blob/70b3d1adc59a9e53d23b569554466576186480c6/frameworks/Java/servlet3-cass/src/main/java/fi/markoa/tfb/servlet3/MessageDAO.java
• https://github.com/TechEmpower/FrameworkBenchmarks/blob/70b3d1adc59a9e53d23b569554466576186480c6/frameworks/Java/servlet3-cass/src/main/java/fi/markoa/tfb/servlet3/DatabaseUpdatesServlet.java
• https://github.com/TechEmpower/FrameworkBenchmarks/blob/70b3d1adc59a9e53d23b569554466576186480c6/frameworks/Java/servlet3-cass/src/main/java/fi/markoa/tfb/servlet3/DatabaseQueryServlet.java
• https://github.com/TechEmpower/FrameworkBenchmarks/blob/70b3d1adc59a9e53d23b569554466576186480c6/frameworks/Java/servlet3-cass/src/main/java/fi/markoa/tfb/servlet3/DatabaseQueriesServlet.java
• https://github.com/TechEmpower/FrameworkBenchmarks/blob/70b3d1adc59a9e53d23b569554466576186480c6/frameworks/Java/servlet3-cass/src/main/java/fi/markoa/tfb/servlet3/DatabaseBaseServlet.java
• https://github.com/TechEmpower/FrameworkBenchmarks/blob/70b3d1adc59a9e53d23b569554466576186480c6/frameworks/Java/servlet3-cass/source_code

[zloster]

Resin 4.0.55 doesn't support Servlet 3.1. Servlet 3.1 has the async IO support. We will need Apache Tomcat sooner.

[zloster]

OK. Tomcat 9.0.4 installation is working. Got some benchmark data. Now trying to build APR tomcat-native adapter for faster native I/O. It requires OpenSSL 1.0.2 but Ubuntu 14.04 comes with 1.0.1x.

[zloster]

There are three components here: APR, OpenSSL 1.0.2 and Tomcat native bindings to ARP. They should be build together. Currently I get warnings in Tomcat log file (catalina.out) when trying to load the ARP library.

[zloster]

Managed to make Tomcat 9 to use ARP and OpenSSL 1.0.2.

07-Feb-2018 19:57:05.116 INFO [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent Loaded APR based Apache Tomcat Native library [1.2.16] using APR version [1.5.1].
07-Feb-2018 19:57:05.117 INFO [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent APR capabilities: IPv6 [true], sendfile [true], accept filters [false], random [true].
07-Feb-2018 19:57:05.119 INFO [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent APR/OpenSSL configuration: useAprConnector [false], useOpenSSL [true]

Played also with the various connector implementations and some tweaks: NIO2 seems the best. But it is loosing against Resin 4.0.53. JSON test heaviest: 4400 rps vs 3550 rps. But Resin already shows saturation - the RPS is falling with the heavier load.

[zloster]

The shell scripts with Tomcat 9.0.4, OpenSSL 1.0.2, Apache APR 1.6.3, Tomcat Native connector compilation, installation and so on are ready.
Also basic setup of server.xml with NIO2 connector.