|From:||Oleksii Kliukin <alexk(at)hintbits(dot)com>|
|To:||Kyotaro HORIGUCHI <horiguchi(dot)kyotaro(at)lab(dot)ntt(dot)co(dot)jp>|
|Cc:||petr(dot)jelinek(at)2ndquadrant(dot)com, cyberdemn(at)gmail(dot)com, sfrost(at)snowman(dot)net, magnus(at)hagander(dot)net, sawada(dot)mshk(at)gmail(dot)com, pgsql-hackers(at)postgresql(dot)org|
|Subject:||Re: Connection slots reserved for replication|
|Views:||Raw Message | Whole Thread | Download mbox|
> On 24. Jan 2019, at 13:47, Kyotaro HORIGUCHI <horiguchi(dot)kyotaro(at)lab(dot)ntt(dot)co(dot)jp> wrote:
Thank you for the review.I took a liberty to address it with v9.
> Documentation looks fine for me. By the way, a comment for the
> caller-site of CheckRequreParameterValues() in xlog.c looks
> somewhat stale.
>> /* Check to see if any changes to max_connections give problems */
> may be better something like this?:
>> /* Check to see if any parameter change gives a problem on replication */
I changed it to "Check if any parameter change gives a problem on recovery”, as I think it is independent of the [streaming] replication, but I still don’t like the wording, as it just duplicate the comment at the definition of CheckRequiredParameterValues. Maybe remove the comment altogether?
> In postinit.c:
>> * The last few connection slots are reserved for superusers.
>> if ((!am_superuser && !am_walsender) &&
>> ReservedBackends > 0 &&
> This is forgetting about explaing about walsenders.
>> The last few connection slots are reserved for
>> superusers. Replication connections don't share the same slot
> Or something?
I changed it to
+ * The last few connection slots are reserved for superusers.
+ * Replication connections are drawn from a separate pool and
+ * not limited by max_connections or superuser_reserved_connections.
> And the parentheses enclosing "!am_superuser..walsender" seems no
> longer needed.
> In guc.c:
> - /* see max_connections and max_wal_senders */
> + /* see max_connections */
> I don't understand for what reason we should see max_connections
> just above. (Or even max_wal_senders) Do we need this comment?
> (There're some other instances, but they wont'be for this patch.)
I don’t understand what is it pointing to as well, so I’ve removed it.
> In pg_controldata.c:
> + printf(_("max_wal_senders setting: %d\n"),
> + ControlFile->max_wal_senders);
> printf(_("max_worker_processes setting: %d\n"),
> printf(_("max_prepared_xacts setting: %d\n"),
> The added item seems to want some additional spaces.
Good catch, fixed.
Attached is v9. I also bumped up the PG_CONTROL_VERSION to 1200 per the prior comment by Robert.
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