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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Hi,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">(I put this in the PR, but maybe drafts don’t get updates put on the mailing list?)<o:p></o:p></span></p>
<p style="margin-bottom:12.0pt;background:white"><span style="font-size:10.5pt;font-family:"Segoe UI",sans-serif;color:#1F2328">HeapDumpOverwrite sounds quite general, there are different ways of heap dumping and this doesn't affect all of them. This could
be HeapDumpOnOutOfMemoryErrorOverwrite, which is a long option even for us 8-) so could be abbreviated perhaps, BUT that option might not be the way to do it…<o:p></o:p></span></p>
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<span style="font-size:10.5pt;font-family:"Segoe UI",sans-serif;color:#1F2328">Is it really that all heap dumps should be permitted to an existing file, IF that file is a FIFO? From the email I think that's the problem? ..and if so, we have:<o:p></o:p></span></p>
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<span style="font-size:10.5pt;font-family:"Segoe UI",sans-serif;color:#1F2328">8267666: Add option to jcmd GC.heap_dump to use existing file<br>
<a href="https://bugs.openjdk.org/browse/JDK-8267666"><span style="text-decoration:none">https://bugs.openjdk.org/browse/JDK-8267666</span></a><o:p></o:p></span></p>
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<span style="font-size:10.5pt;font-family:"Segoe UI",sans-serif;color:#1F2328">So if jcmd to create a dump can use an existing file, -XX:OnError= can trigger such a jcmd?
<br>
<br>
i.e. Maybe there is a way of doing what you want. A code change could still be required to make this easier for heap dumps on out of memory. Writing a JBS bug first is useful to define the problem.<br>
<br>
Thanks<br>
Kevin<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif"> jdk-dev <jdk-dev-retn@openjdk.org>
<b>On Behalf Of </b>Elon Azoulay<br>
<b>Sent:</b> 25 May 2023 21:21<br>
<b>To:</b> Daniel Daugherty <daniel.daugherty@oracle.com><br>
<b>Cc:</b> serviceability-dev@openjdk.org; jdk-dev@openjdk.org<br>
<b>Subject:</b> Re: [External] : Re: Proposal: Add overwrite heapdump flag to java<o:p></o:p></span></p>
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<p class="MsoNormal">Sounds good, thanks so much!<o:p></o:p></p>
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<p class="MsoNormal">On Thu, May 25, 2023 at 12:13 PM <<a href="mailto:daniel.daugherty@oracle.com">daniel.daugherty@oracle.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-family:"Courier New"">Pointing the older thread to this newer incarnation would be a good idea.<br>
<br>
Dan<br>
<br>
</span><o:p></o:p></p>
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<p class="MsoNormal">On 5/25/23 3:11 PM, Elon Azoulay wrote:<o:p></o:p></p>
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<p class="MsoNormal">Hi Dan, <o:p></o:p></p>
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<p class="MsoNormal">That's great! Should I follow up in that thread as well?<o:p></o:p></p>
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<p class="MsoNormal">On Thu, May 25, 2023 at 12:04 PM <<a href="mailto:daniel.daugherty@oracle.com" target="_blank">daniel.daugherty@oracle.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">Greetings,<br>
<br>
A similar request came up on the hotspot-dev alias back in 2022.11:<br>
<br>
<a href="https://mail.openjdk.org/pipermail/hotspot-dev/2022-November/066956.html" target="_blank">https://mail.openjdk.org/pipermail/hotspot-dev/2022-November/066956.html</a><br>
<br>
Dan<br>
<br>
<br>
On 5/25/23 1:48 AM, David Holmes wrote:<br>
> Hi Elon,<br>
><br>
> I would suggest taking this up on serviceability-dev - cc'd.<br>
><br>
> On 25/05/2023 3:46 am, Elon Azoulay wrote:<br>
>> Hi,<br>
>> I submitted a pull request <br>
>> <<a href="https://urldefense.com/v3/__https:/github.com/openjdk/jdk/pull/13276__;!!ACWV5N9M2RV99hQ!P4XNOUSVFXTWEIX8H89o1hhVY4MkuYC-SezupmhJPMkq4ytSpJqLz-jQjNkp906DjKBK_EuRIoL1MtBM2AGEbVqkI0M$" target="_blank">https://github.com/openjdk/jdk/pull/13276</a>>
to expose the overwrite <br>
>> flag to HeapDumpOnOutOfMemoryError.<br>
>> The flag is already exposed to jcmd as -overwrite.This is to <br>
>> facilitate creating a heapdump within a container native environment.<br>
>> We use this internally to dump the heap dump to a fifo so that we <br>
>> could read it in a separate container.Let me know what needs to be <br>
>> done in terms of creating an issue and getting my pr merged.<br>
><br>
> Have you gone through the guide:<br>
><br>
> <a href="https://openjdk.org/guide/" target="_blank">https://openjdk.org/guide/</a><br>
><br>
> ?<br>
><br>
> You will need a JBS issue and also a CSR request as this proposes to <br>
> add a new manageable product flag.<br>
><br>
> Cheers,<br>
> David<br>
><br>
>> I am a new contributor and would be happy to contribute more!<br>
>><br>
>> Cheers,<br>
>><br>
>> Elon<o:p></o:p></p>
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