Re: post-freeze damage control

On Thu, Apr 11, 2024 at 5:48 PM David Steele <david@pgmasters.net> wrote:
> But they'll try because it is a new pg_basebackup feature and they'll
> assume it is there to be used. Maybe it would be a good idea to make it
> clear in the documentation that significant tooling will be required to
> make it work.

I don't agree with that idea. LOTS of what we ship takes a significant
amount of effort to make it work. You may well need a connection
pooler. You may well need a failover manager which may or may not be
separate from your connection pooler. You need a backup tool. You need
a replication management tool which may or may not be separate from
your backup tool and may or may not be separate from your failover
tool. You probably need various out-of-core connections for the
programming languages you need. You may need a management tool, and
you probably need a monitoring tool. Some of the tools you might
choose to do all that stuff themselves have a whole bunch of complex
dependencies. It's a mess.

Now, if someone were to say that we ought to talk about these issues
in our documentation and maybe give people some ideas about how to get
started, I would likely be in favor of that, modulo the small
political problem that various people would want their solution to be
the canonical one to which everyone gets referred. But I think it's
wrong to pretend like this feature is somehow special, that it's
somehow more raw or unfinished than tons of other things. I actually
think it's significantly *better* than a lot of other things. If we
add a disclaimer to the documentation saying "hey, this new
incremental backup feature is half-finished garbage!", and meanwhile
the documentation still says "hey, you can use cp as your
archive_command," then we have completely lost our minds.

I also think that you're being more negative about this than the facts
justify. As I said to several colleagues today, I *fully* acknowledge
that you have a lot more practical experience in this area than I do,
and a bunch of good ideas. I was really pleased to see you talking
about how it would be good if these tools worked on tar files - and I
completely agree, and I hope that will happen, and I hope to help in
making that happen. I think there are a bunch of other problems too,
only some of which I can guess at. However, I think saying that this
feature is not realistically intended to be used by end-users or that
they will not be able to do so is over the top, and is actually kind
of insulting. There has been more enthusiasm for this feature on this
mailing list and elsewhere than I've gotten for anything I've
developed in years. And I don't think that's because all of the people
who have expressed enthusiasm are silly geese who don't understand how
terrible it is.

--
Robert Haas
EDB: http://www.enterprisedb.com