Re: BUG #17005: Enhancement request: Improve walsender throughput by aggregating multiple messages in one send - Mailing list pgsql-bugs

From Andres Freund
Subject Re: BUG #17005: Enhancement request: Improve walsender throughput by aggregating multiple messages in one send
Date
Msg-id 20210517162753.lmhmnfd72bn3nfms@alap3.anarazel.de
Whole thread Raw
In response to Re: BUG #17005: Enhancement request: Improve walsender throughput by aggregating multiple messages in one send  (Yura Sokolov <y.sokolov@postgrespro.ru>)
Responses Re: [External] : Re: BUG #17005: Enhancement request: Improve walsender throughput by aggregating multiple messages in one send  (Rony Kurniawan <rony.kurniawan@oracle.com>)
List 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



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