Re: Cluster name in ps output

On 5 May 2014 17:22, Andres Freund <andres(at)2ndquadrant(dot)com> wrote:

> On 2014-05-05 13:07:48 -0400, Tom Lane wrote:
> > Andres Freund <andres(at)2ndquadrant(dot)com> writes:
> > > On 2014-05-05 10:07:46 -0400, Tom Lane wrote:
> > >> Also, -1 for adding another log_line_prefix escape. If you're routing
> > >> multiple clusters logging to the same place (which is already a bit
> > >> unlikely IMO), you can put distinguishing strings in log_line_prefix
> > >> already. And it's not like we've got an infinite supply of letters
> > >> for those escapes.
> >
> > > Using syslog and including the same config file from multiple clusters
> > > isn't that uncommon. But I can live without it.
> >
> > So, if you are sharing a config file, how is it that you can set a
> > per-cluster cluster_name but not a per-cluster log_line_prefix?
>
> Well, it's a included file. With log_line_prefix support just
> cluster_name has to be set per cluster. Without you need string
> interpolation in the config management to include cluster_name in
> log_line_prefix.
>

Attached as cluster-name-in-ps-v3-a.patch is a new version with
the following changes:

* the brackets removed, as suggested by Tom Lane

* static initialization of cluster_name to avoid any possibility
of an uninitialized/null pointer being used before GUC
initialization, as suggested by Andres Freund

* cluster_name moved to config group CONN_AUTH_SETTINGS, on the
basis that it's similar to bonjour_name, but it isn't
really... open to suggestions for a better config_group!

* a small amount of documentation in config.sgml (with
cluster_name under Connection Settings, which probably
isn't right either)

* sample conf file updated to show cluster_name and %C in
log_line_prefix

A shorter version without the log_line_prefix support that Tom didn't
like is attached as cluster-name-in-ps-v3-b.patch. I will try to add these
to the open commitfest, and see if there is something I can usefully
review in return.

I verified that SHOW cluster_name works as expected and you can't
change it with SET.

Thanks,

Thomas Munro