> From: Chuck Yerkes <[EMAIL PROTECTED]> > > Quoting Clifton Royston ([EMAIL PROTECTED]): > > On Wed, Nov 27, 2002 at 11:50:14AM +0100, Jurgen Philippaerts wrote: > > > We are planning to upgrade our pop3 server (currently running on a dual > > > cpu Sun E450) to a more redundant solution. > > > with at least two qpoppers running, and using somekind of centralized > > > storage. > Why? > > What perceived problem do you think you'd solve?
There are lots of reasons for it. Load distribution so that you can use smaller machines to serve your huge base of users. Easing your maintenance schedule by having multiple clones of the same end server, allowing you to take individual machines off-line so you can do maintenance without interrupting your production services, etc. And, really, even if you feel qpopper is reliable enough to be part of a '5 nines' type service, that doesn't mean the machine under qpopper is. (I'm not saying qpopper isn't that good -- the one time I thought qpopper was our problem, it wasn't ... it turned out to in fact be the machine under qpopper, which was having problems with its cache batteries). You can kind of compare it to RAID ... RAID lets you take lots of smaller and less reliable disks and make something bigger and more reliable out of them. You can do the same thing with dynamic clustering of your services. > > Getting the user login data to be shared also has several solutions, > > and though I'm not that familiar with Solaris, I know your options > > there should include LDAP and NIS+ (as well as simply slaving the > > password file from the master server.) > And Radius. And Kerberos for the authentication side ... for the account side, you can use just about anything (once your passwords aren't in the account system, you can even almost trust something as bad as NIS with the accounts themselves). For example, all of our passwords are in kerberos, and we serve non-kerberized mail clients through popper using PAM. The accounts themselves are in hesiod (which is sort of like NIS, only the underlying engine is DNS, giving you all of the flexibility and scalability of DNS).
