Re: Why we are going to have to go DirectIO

From: "Joshua D(dot) Drake" <jd(at)commandprompt(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Stefan Kaltenbrunner <stefan(at)kaltenbrunner(dot)cc>
Cc: Josh Berkus <josh(at)agliodbs(dot)com>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: Why we are going to have to go DirectIO
Date: 2013-12-03 21:42:01
Message-ID: 529E5029.9000407@commandprompt.com
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On 12/03/2013 12:35 PM, Tom Lane wrote:
> Stefan Kaltenbrunner <stefan(at)kaltenbrunner(dot)cc> writes:
>> If we care about our performance on various operating systems it is
>> _OUR_ responsibility to track that closely and automated and report back
>> and only if that feedback loop fails to work we are actually in a real
>> position to consider something as drastical as considering a platform
>> "undependable" or looking into alternatives (like directIO).
>
> +1. I fail to understand why anyone would think it's a good idea for us
> to build our own I/O stack. The resources that would be consumed by that
> would probably be enough to sink the project, or at least ensure that we
> made no progress on any other aspect of the system for a good long time.
> (And I'm just talking development, never mind maintenance.)
>
> Far better to invest some effort in providing decent feedback to the
> platforms we depend on.

Although I am on the same page as Tom and Stefan here, I can certainly
understand Josh's frustration. When you see things like the ext4 bugs or
the recent long slew of performance related issues in relation to
PDFlush, it is enough to make consultants very frustrated with the likes
of Ubuntu and Debian. I would say RedHat too except they learned their
lesson back in the kernel 2.4 days.

Sincerely,

Joshua D. Drake

>
> regards, tom lane
>
>

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