Re: BUG #17005: Enhancement request: Improve walsender throughput by aggregating multiple messages in one send

From: Andres Freund <andres(at)anarazel(dot)de>
To: Yura Sokolov <y(dot)sokolov(at)postgrespro(dot)ru>
Cc: rony(dot)kurniawan(at)oracle(dot)com, pgsql-bugs(at)lists(dot)postgresql(dot)org
Subject: Re: BUG #17005: Enhancement request: Improve walsender throughput by aggregating multiple messages in one send
Date: 2021-05-17 16:27:53
Message-ID: 20210517162753.lmhmnfd72bn3nfms@alap3.anarazel.de
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-bugs

Hi,

On 2021-05-17 16:21:36 +0300, Yura Sokolov wrote:
> Andres Freund писал 2021-05-17 01:44:
> > What kind of network is this? I would have expected that if the network
> > can't keep up the small sends would end up getting aggregated into
> > larger packets anyway? Are you hitting a PPS limit due to the small
> > packages, but not yet the throughput limit?
>
> I believe the reason is more in sys-call and kernel cpu time overhead than
> in network throughput. Especially in this "after meltdown+spectre" time.

Well, enabling Nagle's wouldn't change anything if the issue is just
syscall and not network overhead. Yet the ask was to enable Nagle's...

Greetings,

Andres Freund

In response to

Responses

Browse pgsql-bugs by date

  From Date Subject
Next Message Peter Geoghegan 2021-05-17 18:17:12 Re: BUG #16833: postgresql 13.1 process crash every hour
Previous Message Tom Lane 2021-05-17 16:27:03 Re: BUG #17015: trigger + array + 'md5' -> 'domain kernel: pid ... (postgres), uid ..., was killed: out of swap spac