[pve-devel] [PATCH ha-manager 3/3] watchdog: sync journal after sending expiration related messages

[Thomas Lamprecht]

Am 19.05.25 um 15:09 schrieb Maximiliano Sandoval:
> One sync comes after warning that the watchdog is about to expire, and a
> second right after the watchdog expires.
> 
> To maximize the chances the log will contain entries relevant to a fence
> event. This would be extremely useful for detecting whether a node
> fenced.
> 
> Signed-off-by: Maximiliano Sandoval <m.sandoval at proxmox.com>
> ---
>  src/watchdog-mux.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/src/watchdog-mux.c b/src/watchdog-mux.c
> index e14c768..8669b10 100644
> --- a/src/watchdog-mux.c
> +++ b/src/watchdog-mux.c
> @@ -268,11 +268,13 @@ main(void)
>                          ) {
>                              client_list[i].warning_state = WARNING_ISSUED;
>                              fprintf(stderr, "client watchdog is about to expire\n");
> +                            sync_journal_unsafe();

The "unsafe" is there for a reason, on a loaded machine doing above
might trigger a few times and create a zombie left over process for
each of those.

Simplest fix might be doing a double fork there so that the parent
process does not exist anymore, in which case systemd collects the
child process exit status, albeit that wouldn't be the most efficient
solution.

>                          }
>  
>                          if ((ctime - client_list[i].time) > client_watchdog_timeout) {
>                              update_watchdog = 0;
>                              fprintf(stderr, "client watchdog expired - disable watchdog updates\n");
> +                            sync_journal_unsafe();

This is basically useless compared to the status quo, there is already
such a call a few (compiled) instructions after that branch hits anyway
as we break the main loop then.

>                          }
>                      }
>                  }