Re: [Sqlgrey-users] multiple databases ?

[Lionel B. <lio...@bo...>]

Who Knows wrote the following on 27.09.2005 15:03 :

> Steve Heaven wrote:
>
>>
>> We have successfully setup sqlgrey on one of our incoming mail 
>> servers. We now need to do the same for our other server.
>> We accept mail for ~250 domains. For most of these the two servers 
>> are equal MX priority, so they load share and provide backup for each 
>> other.
>>
>> When setting up sqlgrey on the second server should we create a new 
>> Postgres database or have them share the existing one?
>>
>> We thought that sharing would be the best option, but dont know if 
>> this will work.
>>
>> Thanks
>>
>> Steve
>>  
>>
>> -- 
>> thorNET
>> Internet Services, Consultancy & Training
>> www.thornet.co.uk
>>
> This is not a recommendation, but rather a comment based on my 
> experience. While I beleive that it would be best to have both servers 
> access the same sqlgrey, as I initially configured my 3 mail servers, 
> I have subsequently reconfigured them to use their own due to a 
> production issue.
>
> Recently my main mail server had a problem which in turn caused the 
> sqlgrey database it served to also become unavailable, and allthough 
> the two other mailservers should have picked up the mail handling 
> duties they failed to accept any inbound mail returning soft error 450 
> due to their inability to access the sqlgrey database.
>

Just to clarify:

If you have one SQLgrey sitting on each server running a MX server and 
all of them configured to use the same database you don't have any 
single point of failure.
If one MX fails, the other(s) handle the trafic. If the database server 
fails, all SQLgrey processes switch to passthrough automatically (and 
warn the email address configured in sqlgrey.conf) -> your MX are 
unaffected but the greylisting stops.
If you have one single SQLgrey process and the server it is sitting on 
fails, all "incoming" mail trafic stops (Postfix answers requests with 
"service temporary unavailable" errors).

Lionel.