Re: Protocol version of Attach API

[Chris Plummer]

On 2/26/19 9:34 AM, Erik Gahlin wrote: On 2019-02-26 07:47, Thomas Stüfe wrote: Hi David, Yasumasa, > Do we support connection to later VMs from earlier JDK tools? I could not find the spec about this. So I asked to serviceability folks before filing this to JBS :-) Just to chime in on that, I do not know if it is specified but it is certainly very handy in daily use. I often use old jcmd tools to connect to newer VMs. I always thought that was a neat design. I agree. The tool was designed to be dumb, so it can connect to JVMs regardless of release. If something has changed so that is no longer true, it should be fixed (and backported if needed). Erik So do we all agree that backporting is acceptable for fixing backwards compatibility here? Just want to be clear on that. You would need to get the latest 8u to interact with 13 and later, and 7 and earlier would not work. I'd prefer to keep 8 (and earlier) working without any changes to it if possible. Also want to point out that this issue might be two-way: 8 can't attach to 13 and 13 may have issues attaching to 8 (what happens with the extra argument that is sent?). Chris ..Thomas