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On 11.01.2011 20:36, Ask Bjørn Hansen wrote:
<blockquote
cite="mid:06F5C2E0-E6D5-4B6B-AC69-4060BE228986@develooper.com"
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How can you limit the number of threads? And why would you?
I run Varnish under both Xen and KVM (and there's an instance on 32-bit linux!) - none of them have trouble with our small load (<1000 requests per second). (And all very standard configurations).
- ask</pre>
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<font size="-1"><font face="Verdana">Hi Ask,<br>
<br>
Some background: The hosting plans that use paravirtualization
(such as Virtuozzo) artificially limit some logical resources
such as sockets, pages, virtual memory address space (which you
cannot cheat your way out of by just creating more swap space)
and number of processes. The latter is called "numproc" and has
fairly low values. The dev plan for my project has several such
virtual instances, which however don't allow more than 150
threads for more than 5 minutes. This is quite annoying, but a
real business model and I have to accept that (just as I have to
accept that varnish is a thread-fest) - even more annoying
because both the memory and CPU reserves would otherwise be more
than adequate to serve the application: during the stresstest I
mentioned earlier Varnish is taking up a neglible 4% CPU load
while doing some pretty elaborate pattern/cookie/locale matching
and hashing (yeah, I have a big VCL).<br>
<br>
I thank you all for your valuable input. The earlier posts
delineate an accurate picture of where the limitations of using
varnish on a constrained environment are. Several people use
nginx/varnish cascades (apparently with keep-alive/pipelining)
which is the next step I will be investigating. Thus - for my
part - my questions have been answered and I'd like to close
this topic.<br>
<br>
Best regards,<br>
G.<br>
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