[OpenAFS] Re: Performance issues
Brandon Allbery
allbery.b@gmail.com
Tue, 23 Aug 2011 23:26:18 -0400
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On Tue, Aug 23, 2011 at 23:03, Jaap Winius <jwinius@umrk.nl> wrote:
> Quoting Brandon Allbery <allbery.b@gmail.com>:
>
> First: is the cache big enough? The working set of even a lightweight
>> desktop manager is pretty big.
>>
>
> It's currently set to 128 MB on all of the workstations. I could increase
> that, but by how much? I'm under the impression that, not far beyond this
> point, the returns tend to diminish.
That was the old conventional wisdom, but these days people find 1GB caches
useful (especially since the cache was reorganized to not be flat).
Meanwhile, 128MB will thrash a lot. It *does* depend on usage to some
extent, but for home directories you should almost always have a fairly
large cache.
Third: especially with Iceweasel/Firefox, you'll find that it helps a lot
>> to symlink the cache into /var/tmp or other fast local storage. ...
>>
>
> Actually, each of our physical servers also runs a Squid proxy cache, so we
> decided to simply disable all of the browser caches. Nevertheless, when
> someone's user volume is remote, Iceweasel still runs too slow.
>
It's still using the cache; it's just not persistent now. Last time I
checked, any time Firefox loads images or media for a page, they are loaded
into the cache and (dis)played from there. There used to be a memory cache
once, but not at this (URL) level any more. You really want this to be
local, and maybe even ramdisk.
--
brandon s allbery allbery.b@gmail.com
wandering unix systems administrator (available) (412) 475-9364 vm/sms
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<div dir=3D"ltr">On Tue, Aug 23, 2011 at 23:03, Jaap Winius <span dir=3D"lt=
r"><<a href=3D"mailto:jwinius@umrk.nl">jwinius@umrk.nl</a>></span> wr=
ote:<br><div class=3D"gmail_quote"><blockquote class=3D"gmail_quote" style=
=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div class=3D"im">Quoting Brandon Allbery <<a href=3D"mailto:allbery.b@g=
mail.com" target=3D"_blank">allbery.b@gmail.com</a>>:<br>
<br>
<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex">
First: =C2=A0is the cache big enough? =C2=A0The working set of even a light=
weight<br>
desktop manager is pretty big.<br>
</blockquote>
<br></div>
It's currently set to 128 MB on all of the workstations. I could increa=
se that, but by how much? I'm under the impression that, not far beyond=
this point, the returns tend to diminish.</blockquote><div><br></div>
<div>That was the old conventional wisdom, but these days people find 1GB c=
aches useful (especially since the cache was reorganized to not be flat). =
=C2=A0Meanwhile, 128MB will thrash a lot. =C2=A0It *does* depend on usage t=
o some extent, but for home directories you should almost always have a fai=
rly large cache.</div>
<div><br></div><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex=
;border-left:1px #ccc solid;padding-left:1ex;"><blockquote class=3D"gmail_q=
uote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1e=
x"><div class=3D"im">
Third: =C2=A0especially with Iceweasel/Firefox, you'll find that it hel=
ps a lot<br></div>
to symlink the cache into /var/tmp or other fast local storage. ...<br>
</blockquote>
<br>
Actually, each of our physical servers also runs a Squid proxy cache, so we=
decided to simply disable all of the browser caches. Nevertheless, when so=
meone's user volume is remote, Iceweasel still runs too slow.<br></bloc=
kquote>
<div><br></div><div>It's still using the cache; it's just not persi=
stent now. =C2=A0Last time I checked, any time Firefox loads images or medi=
a for a page, they are loaded into the cache and (dis)played from there. =
=C2=A0There used to be a memory cache once, but not at this (URL) level any=
more. =C2=A0You really want this to be local, and maybe even ramdisk.</div=
>
<div><br></div></div>-- <br>brandon s allbery =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=
=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0<a href=3D"mailto:allbery.b@gmail.com" targe=
t=3D"_blank">allbery.b@gmail.com</a><br>wandering unix systems administrato=
r (available) =C2=A0 =C2=A0 (412) 475-9364 vm/sms<br>
<br>
</div>
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