Re: How many redirectors to spawn?

From: Michael Samuel <>
Date: Thu, 21 May 1998 23:30:28 +1000 (EST)

On Thu, 21 May 1998, Simon Rainey wrote:

> This is probably a dumb question but I'll ask it all the same. I've written
> a Squid redirector in C to block porn. The ever-increasing list of banned
> sites currently runs to 160kB (8700 lines) and the redirector loads this
> into memory at start-up.

This is probably a good start, but you should consider using Dan
Bernstein's cdb package.

Look at (I think that's the URL...)

It is very fast, and does atomic updating, so you won't confuse your
redirector if you update it while somebody accesses it (via a redirector).

Dan actually did a sendmail /etc/aliases clone that uses it (fastforward),
and when running newaliases, he did 50000 new aliases in 6 seconds cpu
time, while sendmail's newaliases did it in 300 seconds cpu time...
Something worth considering, anyway.

> What are the benefits of spawning more than one redirector process given
> that the host has a single CPU? If I spawn more than one then Squid does
> use them all, but the second is hit about 10% of the time while the fifth
> is down below 1%.

You should set it up, so there is always _at least_ one that never gets
used, as a general rule.

AFAIK, spawning more will only cost you filedescriptors (but I could be
wrong), and possibly get you in trouble if you're running short on PIDs

Hope this helps.

Michael Samuel,

Surf-Net City - Internet Cafe and Internet Service Providers
Phone: +61 3 9593-9977
E-Mail: <>
Received on Thu May 21 1998 - 05:32:10 MDT

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