Re: PATCH: pgbench - option to build using ppoll() for larger connection counts - Mailing list pgsql-hackers

From konstantin knizhnik
Subject Re: PATCH: pgbench - option to build using ppoll() for larger connection counts
Date
Msg-id 7931C1C9-BA15-435C-B350-630F766A01B2@postgrespro.ru
Whole thread Raw
In response to Re: PATCH: pgbench - option to build using ppoll() for larger connection counts  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Apr 7, 2018, at 12:49 AM, Tom Lane wrote:

> Andres Freund <andres@anarazel.de> writes:
>> I'm still not particularly happy with this.
>
> I'm a bit confused as to what the point is.  It seems unlikely that one
> pgbench process can effectively drive enough backends for select's
> limitations to really be an issue.

pgbench is multithreaded application, so in theory it can drive almost arbitrary number of connections.
It is limited only by network throughput, but if pgbench is launched at the same host and connected  to the server
throughloopback or unix sockets, 
then network is also not a limit.
We quite often have to spawn more than 1k connections and SMP systems with hundreds of CPU.
So there are two choices: either use patched version of pgbench which is using poll, either spawn several instances of
pgbench(which is not always convenient). 

>
>             regards, tom lane
>



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