DumpJFR tool

[Erik Gahlin]

Hi Yasumasa,

The DumpJFR tool relied on SA, which was too much of a burden to 
maintain (slowing down the development of new JFR features).

I think tool was removed in Oracle JDK 9, at least it was completely 
broken at that time.

Functionality has been added that allows JFR to dump an emergency dump 
if the JVM crashes. This reduces the need for a separate tool.

The Event Streaming JEP, targeted for JDK 14, should also help out here, 
as it ensures the latest file in the disk repository, previously known 
as the .part file, can always read. With a default flush interval of 1 
second, data will be available very close to the point of the crash.

Best regards,
Erik

> Hi all,
>
> DumpJFR tool is introduced in JDK 8u60 [1], however it is not 
> available on OpenJDK (JDK 11 or later).
> Why it is not open sourced?
>
> I think DumpJFR is very useful not only for postmortem analysis but 
> also analyzing process hung up.
> If DumpJFR is available on OpenJDK, I believe JFR will be more useful 
> for troubleshooting.
>
>
> Thanks,
>
> Yasumasa
>
>
> [1] 
> https://www.oracle.com/technetwork/java/javase/8u60-relnotes-2620227.html