Re: [exim] setup Exim to improve SMTP performance

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Autore: Olivier Bonvalet
Data:  
To: exim-users
Oggetto: Re: [exim] setup Exim to improve SMTP performance
So I try to :
- put /var/spool/exim4 on a different partition, with noatime option
- put /var/spool/exim4/db in memory (/dev/shm)
- set "message_logs = false"
- set "split_spool_directory = true"

It didn't change anything, exim send about 280 / 300 emails per minute.

But, I think I found where is the problem : TLS
http://wiki.debian.org/PkgExim4KnownBugsInSarge

I haven't got enough entropy on my servers, and "/dev/random" is "blocking".
I try to replace /dev/random by /dev/urandom, and it seems to be really
really
faster (but I haven't got any stats, since I found this too late).

Now, I'll search to a "true" solution :
- I want to keep "/dev/random" for security purpose
- really don't want to use a compiled version

I prefer to not use "backports", but if I don't found any other
solutions, I'll do.

Thanks all !
Olivier


Olivier Bonvalet a écrit :
> Phil Pennock a écrit :
>> On 2006-03-21 at 17:22 +0100, Olivier Bonvalet wrote:
>>
>>> Have I to set anything else to improve perf ?
>>>
>>
>> Local DNS cache, or LDAP slave if using LDAP for lookups.
>>
> Ok. I already have a local DNS cache, and don't use LDAP.
>
>> If doing many file lookups per recipient, consider building the data
>> into CDB files for faster lookups.
>>
> mmm I forgot to say : recipients are not local at all, all emails are
> for remote smtp servers.
>
>
>> /var/log being a different filesystem from /var/spool/exim/ (not just
>> for the hints).
>>
> mm Ok. I'll try this, and will set "noatime" option for
> /var/spool/exim too.
>
>> Set split_spool_directory.
>>
> I was thinking it was needed only for ext2/ext3. For XFS and JFS too ?
> And what about ReiserFS ?
>
>
>> Look carefully at what happens with your exim Routers; are you
>> spam-scanning the outgoing mail once, at submission, or once per
>> recipient? If all mail sent to your mailing-list software is scanned
>> for spam and malware, then you probably can skip the scanning on the
>> resubmitted emails. Many "template" configurations route mail on a
>> per-recipient basis to spam-scanning first, because they're not designed
>> to deal with that degree of recipient fan-out.
> There is not any spam filter or anti virus on this boxes. They are
> dedicated for the mailing list :
> just Exim which send emails to remote SMTP servers.
>
> For the routers, the config is the "default".
>
>
> Thanks
>
> Olivier
>