KEnet Webmaster wrote:
>
> Im looking at the 4.10 version of vpopmail. What is mysql replication?
> Does that mean that it uses the vpasswd file, but replicates the info to
> mysql, or does it mean that it just makes more than one mysql table?
It means it uses mysql's new replication features.
What does that mean?
It means one mysql server can be setup to be a "master".
Many other mysql servers can be setup to be "slaves" to
the "master".
All SQL that causes a change in the database has to be sent
to the "master". The master will process the SQL then send
updates to all the slaves.
So all the slaves have an exact copy of the master database.
Then all programs that only need to read the data can contact
a "slave" database.
This can be very useful in clustered email setups. Each cluster
machine can have a slave mysql server and thus reduce the read
sql queries on the master.
Basicly this is a poor man's replicated database setup. Poor
because not all situations are taken into account. For example:
if a mysql slave get's hopelessly out of date with the master
(and that doesn't take much:), then the slave has to be rebuilt
from the master database, by hand(or scripts), but not automatically.
