Re: add log messages when replication slots become active and inactive (was Re: Is it worth adding ReplicationSlot active_pid to ReplicationSlotPersistentData?)

On Fri, Mar 24, 2023 at 4:33 AM Bharath Rupireddy
<bharath(dot)rupireddyforpostgres(at)gmail(dot)com> wrote:
>
> On Thu, Mar 23, 2023 at 3:37 PM Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> wrote:
> >
> > On 2023-Mar-22, Amit Kapila wrote:
> >
> > > I see that you have modified the patch to address the comments from
> > > Alvaro. Personally, I feel it would be better to add such a message at
> > > a centralized location instead of spreading these in different callers
> > > of slot acquire/release functionality to avoid getting these missed in
> > > the new callers in the future. However, if Alvaro and others think
> > > that the current style is better then we should go ahead and do it
> > > that way. I hope that we should be able to decide on this and get it
> > > into PG16. Anyone else would like to weigh in here?
> >
> > I like Peter Smith's suggestion downthread.
>
> +1. Please review the attached v8 patch further.
>

Patch v8 applied OK, and builds/renders the HTML docs OK, and passes
the regression and subscription TAP tests OK.

(Note - I didn't do any additional manual testing, and I've assumed it
to be covering all the necessary acquire/related logging that you
wanted).

~~

Here are some minor comments:

1.
+ ereport(log_replication_commands ? LOG : DEBUG3,
+ (errmsg("acquired physical replication slot \"%s\"",
+ slotname)));

AFAIK those extra parentheses wrapping the "errmsg" part are not necessary.

~~

2.
extern void LogReplicationSlotAquired(bool is_physical, char *slotname);
extern void LogReplicationSlotReleased(bool is_physical, char *slotname);

The "char *slotname" params of those helper functions should probably
be declared and defined as "const char *slotname".

~~

Otherwise, from a code review perspective the patch v8 LGTM.

------
Kind Regards,
Peter Smith.
Fujitsu Australia