On Tue, 21 Nov 2023 17:57:32 GMT, Kevin Walls <kev...@openjdk.org> wrote:
> RMI Connections (in general) should use a timeout on the Socket connect call > by default. > > JMX connections use RMI and some connection failures never terminate. The > hang described in 8316649 is hard to reproduce manually: the description says > it can be caused by a firewall that never returns a response. > > src/java.rmi/share/classes/sun/rmi/transport/tcp/TCPChannel.java > has other timeouts but nothing to control the initial Socket connect. > > Defaulting to a 1 minute timeout on connect has no effect on existing tests > for RMI and JMX, and should go unnoticed in applications unless there really > is a significant connection delay. Specifying zero for the new System > Property sun.rmi.transport.tcp.initialConnectTimeout uses the old code path > of a connect with no timeout. > > I have a test, but it is not realistically usable: although specifying a 1 > millisecond timeout will often fail (as expected/desired for the test), it > will often pass as the connection happens immediately. It may be that changing the base RMI implementation isn't desirable. I am bringing up a different implementation, using a new ClientSocketFactory for JMX which implements the connect timeout. So a new JMX-specific property, not a general RMI property, and we limit the impact of the change, so it won't affect any other RMI apps. I'm putting this in https://github.com/openjdk/jdk/pull/16856 it's in draft right now, I'll complete the details and see if it is a better way forward (will close this PR if the new one is better). ------------- PR Comment: https://git.openjdk.org/jdk/pull/16771#issuecomment-1830309421
