Re: [HACKERS] PATCH: Make pg_stop_backup() archive wait optional

On 3/1/17 5:11 PM, Jim Nasby wrote:
> On 2/27/17 6:25 PM, David Steele wrote:
>> The purpose of this patch is to make waiting for archive optional, with
>> the default being the current behavior, i.e., to wait for all WAL to be
>> archived.  This functionality is already used internally by
>> pg_basebackup, so the only real change is to expose it through the
>> pg_stop_backup() function.
> 
> Do the docs mention anywhere how to monitor WAL archiving to know if
> you've got all the necessary WAL? Perhaps a function to do that would be
> worth adding.

The docs in the patch mention that this option should only be used by
backup solutions that know how to monitor archiving:

+    This behavior is only useful for backup
+    software which independently monitors WAL archiving, otherwise WAL
+    required to make the backup consistent might be missing and make
the backup
+    useless.

There is already a view, pg_stat_archiver, that allows a program to see
what has been archived.  I'm not sure we'd be adding much by putting a
function around that.

I would be OK with adding a link to pg_stat_archiver in the
pg_stop_backup() documentation to if that seems appropriate.

-- 
-David
david@pgmasters.net