Milter-greylist

--- In milter-greylist@yahoogroups.com, Eduardo Casarero
<eduardo.casarero@...> wrote:
> I would prefer to have a "dummy greylist daemon" with something like
this http://www.ispras.ru/~knizhnik/fastdb/readme.htm as DB. All the
20 greylists have this dummy greylist configured as peer (only 1) and
they send to this dummy peer all the transaccions. As the transactions
gets into the dummy, it's replyes to the other 19 clients. 


This is a good idea, and will help milter-greylist to handle larger
server clusters. The dummy daemon basically acts as a home-grown DB
server. There are two problems with it, though:

1. There is a limit to the scalability. Increasing the number of mail
servers, the load on the dummy greylist daemon will eventually become
too high and the setup will break

2. There is a reliability issue. If the dummy daemon fails,
greylisting on the whole server cluster fails. It breaks the
redundancy inherent to multiple mx servers for a single domain.

Have a look at http://en.wikipedia.org/wiki/MySQL_Cluster. These
database guys know how to do high availability and performance
clustering. Why not take advantage of that?