Fw: Distributed Postfix
- ThanksI have refered to split only postfix functions,but for it ,is need create coherent users system.For example if I create one user in gmail system,this user physical is stored only one central machine then is accesed through diverse distribute mechanism (same DNS),or is replicate in all machine?----- Original Message -----From: Bill ColeSent: Tuesday, March 26, 2013 16:00Subject: Re: Distributed PostfixOn 26 Mar 2013, at 6:51, Gaby L wrote:
> My teoretic question is how configure multiple (distributed) postfix
> mail servers for one domain,which can load balance tasks? (e.g
> gmail),but all servers same (unique) users list,alias,rules for one
As Dr. Venema's answer implies, splitting up functions (especially
non-Postfix functions) between different sets of machines is the first
step, as it is easier to distribute limited subsets of work across many
machines than to replicate everything on every box and keep them all
coherent. A corollary of this is that you need to start by
understanding what your "Postfix mail server" actually is doing.
Inbound, outbound, and internal mail can be split apart between distinct
Postfix configurations, while access to delivered mail (i.e. IMAP, POP,
or webmail) is a non-Postfix function that is inherently the most
difficult part of a "mail server" to distribute across many nodes.
Because large-scale "mail servers" aren't all "large" in the same way,
how one should split up and replicate functionality between machines is
dependent on the details of what the whole system is doing.
- On 27 Mar 2013, at 8:32, Gaby L wrote:
> ThanksI'm not completely certain that I understand what you are asking about,
> I have refered to split only postfix functions,but for it ,is need
> create coherent users system.
> For example if I create one user in gmail system,this user physical is
> stored only one central machine then is accesed through diverse
> distribute mechanism (same DNS),or is replicate in all machine?
but I'll try to provide something like an answer.
Stored mail is not managed by Postfix. Once mail is delivered, Postfix
never touches it again. Access to delivered mail is handled by IMAP,
POP, and Webmail software. Postfix is none of those.
The fact that a user account exists, the details of how mail is
delivered to that account, and its authentication mechanism (used to
allow a user to submit mail) are used directly Postfix. In a distributed
Postfix environment there are multiple options you could use to make
those aspects of the account accessible to multiple Postfix instances,
and choosing between them must be informed by the details of the
specific environment. Postfix is a user of that information, not the
manager of it. Postfix can access user information via LDAP, MySQL,
memcache, a generic socket protocol, and from file in a variety of
formats including dbm, BerkeleyDB, and CDB. Postfix can use the SASL
authentication libraries of Cyrus or Dovecot. All of these options exist
because they fit different types of environment. There is not a single