W B Hacker <wbh@???> (Do 25 Jan 2007 22:27:54 CET):
> Rob Munsch wrote:
> > Hello list.
> >
> > Due to increasingly fascist local antispam policies, we are of course
> > bouncing a lot of people's mail. Such people are invariably the friends
> > and/or business contacts of Important People in the office.
> >
> > I'm using an
> >
> > accept
> > senders = lsearch*@;/etc/exim4/local_whitelist
> >
> > before my ACLs start getting nasty, which a flat file containing the
> > addresses of People Who Should Never Be Blocked. But naturally now that
> > the existance of this file is known, everyone wants in on it. One
> > enterprising department forwarded me a spreadsheet of 2000 addresses
> > "who we never want to get bounces," most of them from @gmail.
> >
> > So:
> >
> > 1) How large can this local_whitelist get before i start doing Horrible
> > Things to my server's performance?
>
> With most modern CPU, MB, memory, HDD, and file systems, probably well into
> tens of thousands of entries. Even then not 'horrible' - just not optimal.
citing my self:
>From hs@??? Mon Jan 1 20:07:07 2007
Date: Mon, 1 Jan 2007 20:07:07 +0100
From: Heiko Schlittermann <hs@???>
To: exim-users@???
Subject: Re: [exim] [follow-up?] Re: Performance of MySQL vs text files.
....
First, time for exim startup:
# time exim4 -bV >/dev/null
real 0m0.032s
user 0m0.020s
sys 0m0.010s
Now, flat file (about 5000 lines)
# time exim4 -be '${lookup{217.72.192.234}lsearch{/tmp/seen.txt}}'
# looking up the first entry in this file:
real 0m0.031s
user 0m0.030s
sys 0m0.000s
# looking up the very last entry in this file:
real 0m0.036s
user 0m0.020s
sys 0m0.020s
Now, same with DBM (about 5000 entries)
# time exim4 -be '${lookup{217.72.192.234}dbm{/tmp/seen.db}}'
# (there's no difference between the last and the first
# entry, as expected)
real 0m0.032s
user 0m0.030s
sys 0m0.000s
And now using sqlite
# time exim4 -be '${lookup sqlite{/tmp/seen.sql SELECT * FROM seen WHERE item = "217.72.192.234"}}
real 0m0.033s
user 0m0.030s
sys 0m0.000s
And finally mysql (using local unix socket)
# time exim4 -be '${lookup mysql{SELECT * FROM seen WHERE item = "217.72.192.234"}}
real 0m0.034s
user 0m0.010s
sys 0m0.020s
Until here we do not see some significant difference, but it should be
expected that DBM and SQLite/MySQL will scale better than the flat file.
(For getting more significant data and to eleminate the time exim loads itself I'd
create a small perl "plugin" executing several hundreds of lookups via Exim::expand_string().)
....
Best regards from Dresden
Viele Grüße aus Dresden
Heiko Schlittermann
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