Re: Why we are going to have to go DirectIO

On 12/03/2013 10:44 AM, Josh Berkus wrote:
>
> All,
>
> https://lkml.org/lkml/2013/11/24/133
>
> What this means for us:
>
> http://citusdata.com/blog/72-linux-memory-manager-and-your-big-data
>
> It seems clear that Kernel.org, since 2.6, has been in the business of
> pushing major, hackish, changes to the IO stack without testing them or
> even thinking too hard about what the side-effects might be. This is
> perhaps unsurprising given that two of the largest sponsors of the
> Kernel -- who, incidentally, do 100% of the performance testing -- don't
> use the IO stack.
>
> This says to me that Linux will clearly be an undependable platform in
> the future with the potential to destroy PostgreSQL performance without
> warning, leaving us scrambling for workarounds. Too bad the
> alternatives are so unpopular.
>
> I don't know where we'll get the resources to implement our own storage,
> but it's looking like we don't have a choice.
>

This seems rather half cocked. I read the article. They found a problem,
that really will only affect a reasonably small percentage of users,
created a test case, reported it, and a patch was produced.

Kind of like how we do it.

JD

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