[systemd-devel] journal handling of process title changes

[Patrick Donnelly]

On Mon, Mar 24, 2014 at 12:30 PM, Lennart Poettering
<lennart at poettering.net> wrote:
> On Sun, 23.03.14 21:46, Patrick Donnelly (batrick at batbytes.com) wrote:
>
>> My problem is not related to race conditions. The issue is that
>> /proc/pid/cmdline is shown instead of /proc/pid/comm for each journal
>> entry. That is:
>>
>> $ journalctl --boot
>> [...]
>> Mar 23 21:39:01 host a.out[10697]: hi
>> Mar 23 21:39:01 host c[10697]: bye2
>> [...]
>>
>> These identifiers are being pulled from cmdline or argv[0] somehow.
>
> Yupp, the client side also sends an identifier to the server which is
> used if it exists. It's container in the SYSLOG_IDENTIFIER field.
>
> I figure what happens for you is that when you change argv[0] the GNU
> program_invocation_short_name variable is not updated, and sd-journal
> picks up that variable for setting SYSLOG_IDENTIFIER.

Yes, this is it. Yay obscure glibc side-effects.

I assume I could just override SYSLOG_IDENTIFIER manually? Also, if
someone could update the documentation for systemd.journal-fields(7)
saying where SYSLOG_IDENTIFIER is derived (by default?), that'd
probably help too.

Thanks Lennart!

-- 
Patrick Donnelly