Jetty / jersey / apache httpclient connection pooling problems

Simple spring boot + jersey + jetty projects with following versions:

• Spring Boot: 2.1.8.RELEASE
• Jetty: 9.4.19.v20190610 (via spring)
• Jersey: 2.27 (via spring)

To reproduce:

• start server

  $ ./gradlew bootRun

• start client

  $ ./gradlew bootRun

• generate load on client

  $ ab -n 10000 -c 5 http://localhost:6800/v1/test

The client should receive multiple broken pipes during execution because the server jetty closes the pooled connections after a few requests.

[qtp801284613-18] o.apache.http.impl.execchain.RetryExec   : I/O exception (java.net.SocketException) caught when processing request to {}->http://localhost:6700: Broken pipe (Write failed)

With debug logging, the server projects jetty seems to think there is uncosumed input.

Fixes / bandaids

Enable filter

Uncomment @Component from the server projects test.jetty.config.Filter. This filter was a suggestion from jetty/jetty.project#2867.

Submit empty arrays from client to server

If you comment out

params.add("ARR" + i);

from test.jetty.rest.TestEndpoint in the client project the problem goes away. Any array size of >0 seems to cause the problem to happen.