Re: What are exactly bootstrap processes, auxiliary processes, standalone backends, normal backends(user sessions)?

On Tue, Sep 7, 2021 at 5:48 AM Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
>
> On 2021-Aug-14, Justin Pryzby wrote:
>
> > I elaborated on your definition and added here.
> > https://commitfest.postgresql.org/34/3285/
>
> Thanks!  This works for me.  After looking at it, it seemed to me that
> listing the autovacuum launcher is perfectly adapted, so we might as
> well do it; and add verbiage about it to the autovacuum entry.  (I was
> first adding a whole new glossary entry for it, but it seemed overkill.)
>
> I also ended up adding an entry for WAL sender -- seems to round things
> nicely.
>
> ... In doing so I noticed that the definition for startup process and
> WAL receiver is slightly wrong.  WAL receiver only receives, it doesn't
> replay; it is always the startup process the one that replays.  So I
> changed that too.

Thanks for the v2 patch, here are some comments on it:

1) How about
A set of background processes (<firstterm>autovacuum
launcher</firstterm> and <firstterm>autovacuum workers</firstterm>)
that routinely perform
instead of
A set of background processes that routinely perform
?

2) In what way we call autovacuum launcher an auxiliary process but
not autovacuum worker? And autovacuum isn't a background worker right?
Why can't we call it an auxiliary process?
+     (but not the autovacuum workers),

3) Isn't it "WAL sender" instead of "WAL senders"?
+     (but not the <glossterm linkend="glossary-wal-sender">WAL
senders</glossterm>),


4) replays WAL during replication? Isn't it "replays WAL during crash
recovery or in standby mode"
+     An auxiliary process that replays WAL during replication and
+     crash recovery.

5) Should we mention that WAL archiver too is optional similar to
Logger (process)? Also, let us rearrange the text a bit to be in sync.
+     An auxiliary process which (if enabled) saves copies of
+     <glossterm linkend="glossary-wal-file">WAL files</glossterm>

+     An auxiliary process which (if enabled)
      writes information about database events into the current

6) Shouldn't we mention "<glossterm
linkend="glossary-auxiliary-proc">auxiliary process</glossterm>
instead of just plain "auxilary process"?

7) Shouldn't we mention "<glossterm
linkend="glossary-primary-server">primary</glossterm>"? instead of
"primary server"?
+     to receive WAL from the primary server for replay by the

8) I agree to not call walsender an auxiliary process because it is
type of a <glossterm linkend="glossary-backend">backend</glossterm>
process that understands replication commands only. Instead of saying
"A process that runs..."
why can't we mention that in the description?
+     A process that runs on a server that streams WAL over a
+     network.  The receiving end can be a
+     <glossterm linkend="glossary-wal-receiver">WAL receiver</glossterm>

Regards,
Bharath Rupireddy.