Re: Minimizing Recovery Time (wal replication)

On Thu, 9 Apr 2009, Bryan Murphy wrote:

>> 1) Decrease the maximum possible segment backlog so you can never get this
>>   far behind
>
> I understand conceptually what you are saying, but I don't know how to
> practically realize this. :) Do you mean lower checkpoint_segments?

Theoretically, every time the archive_command writes a new segment out you
can immediately move that to your standby, and setup the standby to
regularly look for those and apply them as they come in. The fact that
you're getting so many of them queued up suggests there's something in
that path that isn't moving that pipeline along aggressively enough,
without knowing more about what you're doing it's hard to say where that
is.

> It actually is an 8 drive raid 10, BUT, it's on virtualized
> infrastructure up in Amazon's cloud running on 8 EBS volumes. I've
> found performance to be... inconsistent at best.

Yeah, EBS is not exactly a high-performance or predictable database
storage solution, particularly when you get to where you're calling fsync
a lot--which is exactly what is happening during the period you note your
system is frozen.

--
* Greg Smith gsmith(at)gregsmith(dot)com http://www.gregsmith.com Baltimore, MD
>From pgsql-general-owner(at)postgresql(dot)org Thu Apr 9 21:48:37 2009
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From: linnewbie <linnewbie(at)gmail(dot)com>
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Subject: Re: Storing HTML: HTML entities being rendered in that raw form
Date: Thu, 9 Apr 2009 17:32:18 -0700 (PDT)
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On Apr 9, 1:00=A0pm, st(dot)(dot)(dot)(at)blighty(dot)com (Steve Atkins) wrote:
> On Apr 9, 2009, at 9:27 AM, linnewbie wrote:
>
> > Hi all,
>
> > I have stored HTML in a text field that I subsequently render on the
> > web. =A0However when I retrieve and render this data on the web I =A0am
> > getting the entities being rendered in their raw form, ie, instead of
> > getting the '&' symbol when '&amp;' is stored =A0I'm getting the 'raw'
> > '&amp;'.
>
> > I would be grateful if anyone can point out how I can get around this.
>
> It's a problem in your code, not the database. You're probably
> escaping it one time to many or unescaping it one time too few.
>
> Cheers,
> =A0 =A0Steve
>
> --
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gsql-general

To clarify, I am not escaping the string in any way.

Say the page I am saving the database is the about us page form a
company website.
First, make a from to create the about us page in a text area field,
then I copy the
html from my text editor and past it ino this text area from. I then
have a cgi script which
takes the contents from the text area field and stores it in the
database.

What I have on disk would be:

................................
..............................
<p> Bonnie &amp; Clyde</p>

which would usually be rendered as:

Bonnie & Clype

but this is not happening, it's being rendered
as:

Bonnie &amp; Clyde