The following test failed in the JDK16 CI:

sun/tools/jstatd/TestJstatdRmiPort.java

Here's a snippet from the log file:

--- ProcessLog ---
cmd: /scratch/mesos/jib-master/install/jdk-16+27-1887/macosx-x64-debug.jdk/jdk-16/fastdebug/bin/jstatd -J-XX:+UsePerfData -J-Djava.security.policy=/scratch/mesos/jib-master/install/jdk-16+27-1887/src.full/open/test/jdk/sun/tools/jstatd/all.policy -p 65525 -r 65526
exitvalue: 143
stderr:
stdout:

[2020-12-03T12:20:47.466203Z] Waiting for completion for process 69523
[2020-12-03T12:20:47.466441Z] Waiting for completion finished for process 69523

Start jstatd:
[/scratch/mesos/jib-master/install/jdk-16+27-1887/macosx-x64-debug.jdk/jdk-16/fastdebug/bin/jstatd -J-XX:+UsePerfData -J-Djava.security.policy=/scratch/mesos/jib-master/install/jdk-16+27-1887/src.full/open/test/jdk/sun/tools/jstatd/all.policy -p49152 -r49153]
[Jstatd-Thread]:/scratch/mesos/jib-master/install/jdk-16+27-1887/macosx-x64-debug.jdk/jdk-16/fastdebug/bin/jstatd -J-XX:+UsePerfData -J-Djava.security.policy=/scratch/mesos/jib-master/install/jdk-16+27-1887/src.full/open/test/jdk/sun/tools/jstatd/all.policy -p49152 -r49153
[Jstatd-Thread] Could not bind //:49152/JStatRemoteHost to RMI Registry
[Jstatd-Thread] java.rmi.ConnectIOException: error during JRMP connection establishment; nested exception is:
[Jstatd-Thread] java.net.SocketTimeoutException: Read timed out
[Jstatd-Thread] at java.rmi/sun.rmi.transport.tcp.TCPChannel.createConnection(TCPChannel.java:300)
[Jstatd-Thread] at java.rmi/sun.rmi.transport.tcp.TCPChannel.newConnection(TCPChannel.java:196)
[Jstatd-Thread] at java.rmi/sun.rmi.server.UnicastRef.newCall(UnicastRef.java:343)
[Jstatd-Thread] at java.rmi/sun.rmi.registry.RegistryImpl_Stub.rebind(RegistryImpl_Stub.java:150)
[Jstatd-Thread] at java.rmi/java.rmi.Naming.rebind(Naming.java:177)
[Jstatd-Thread] at jdk.jstatd/sun.tools.jstatd.Jstatd.bind(Jstatd.java:59)
[Jstatd-Thread] at jdk.jstatd/sun.tools.jstatd.Jstatd.main(Jstatd.java:157)
[Jstatd-Thread] Caused by: java.net.SocketTimeoutException: Read timed out
[Jstatd-Thread] at java.base/sun.nio.ch.NioSocketImpl.timedRead(NioSocketImpl.java:283)
[Jstatd-Thread] at java.base/sun.nio.ch.NioSocketImpl.implRead(NioSocketImpl.java:309)
[Jstatd-Thread] at java.base/sun.nio.ch.NioSocketImpl.read(NioSocketImpl.java:350)
[Jstatd-Thread] at java.base/sun.nio.ch.NioSocketImpl$1.read(NioSocketImpl.java:803)
[Jstatd-Thread] at java.base/java.net.Socket$SocketInputStream.read(Socket.java:976)
[Jstatd-Thread] at java.base/jav
result: Error. Agent error: java.lang.Exception: Agent 91 timed out with a timeout of 240 seconds; check console log for any additional details


test result: Error. Agent error: java.lang.Exception: Agent 91 timed out with a timeout of 240 seconds; check console log for any additional details

This sun/tools/jstatd/TestJstatdRmiPort.java failure is different than other
sightings. This is a singleton failure in the test task on the machine so
there isn't interference from another parallel executing testing.

Also, this particular failure trace appears to be unique:

[Jstatd-Thread] Could not bind //:49152/JStatRemoteHost to RMI Registry
[Jstatd-Thread] java.rmi.ConnectIOException: error during JRMP connection establishment; nested exception is:
[Jstatd-Thread] java.net.SocketTimeoutException: Read timed out

Ignoring the port value, I wasn't able to find another bug that mentions
this specific failure mode.