Re: Printing backtrace of postgres processes

On Fri, Nov 12, 2021 at 5:15 PM Bharath Rupireddy
<bharath.rupireddyforpostgres@gmail.com> wrote:
>
> On Thu, Nov 11, 2021 at 12:14 PM vignesh C <vignesh21@gmail.com> wrote:
> > Thanks for the comments, the attached v10 patch has the fixes for the same.
>
> Thanks for the patches. Here are some comments:
>
> 1) In the docs, let's have the similar description of
> pg_log_backend_memory_contexts for pg_print_backtrace, just for the
> continuity in the users readability.

I have kept some contents of the description similar. There is some
additional information to explain more about the functionality. I felt
that will help the user to understand more about the feature.

> 2) I don't know how the <screen> part looks like in the Server
> Signaling Functions table. I think here you can just say, it will emit
> a warning and return false if not supported by the installation. And
> you can give the <screen> part after the description where you are
> showing a sample backtrace.
>
> +        capture backtrace. If not available, the function will return false
> +        and a warning is issued, for example:
> +<screen>
> +WARNING:  backtrace generation is not supported by this installation
> + pg_print_backtrace
> +--------------------
> + f
> +</screen>
> +       </para></entry>
> +      </row>

Modified

> 3) Replace '!' with '.'.
> + * Note: this is called within a signal handler!  All we can do is set

I have changed it similar to HandleLogMemoryContextInterrupt

> 4) It is not only the next CFI but also the process specific interrupt
> handlers (in your 0002 patch) right?
> + * a flag that will cause the next CHECK_FOR_INTERRUPTS to invoke

Modified

> 5) I think you need to update CATALOG_VERSION_NO, mostly the committer
> will take care of it but just in case.

Modified

> 6) Be consistent with casing "Verify" and "Might"
> +# Verify that log output gets to the file
> +# might need to retry if logging collector process is slow...

Modified

The attached v11 patch has the changes for the same.

Regards,
Vignesh