I want to contribute a custom SocketFactory allowing to analyze the utilization
of acceptConnection attribute of a Connector. In a properly configured
production system, there should be rare situations where connections wait for a
worker thread to be handled. Our client complained on high latency of web
requests, but the measurement on servlet did not show high latency. So we wanted
to know the number of connections which wait in socket backlog and were not
accepted yet.

I solved this problem by writing a custom SocketFactory, which accepts
connections immediately and puts it in my queue until a call to accept() will
take them. So the number of waiting connections can be monitored via JMX.

To activate this factory, the declaration of the corresponding Connector in
server.xml should be changed like in the following example.

 <Connector port="8080" maxHttpHeaderSize="8192"
               maxThreads="10" minSpareThreads="5" maxSpareThreads="7"
               enableLookups="false" redirectPort="8443" acceptCount="10"
               connectionTimeout="2000" disableUploadTimeout="true"

              
socketFactory="org.apache.tomcat.util.net.BacklogMeasuringServerSocketFactory"/>


No changes in existing classes are required.

Please review the code in the attachment.