buffered-sql, radsqlrelay and fault resilience

[Yann Belin]

Hi all,

First a good day to you, since this is my first mail in this list.

I am trying to build a multi-server setup, where each server uses a
local user database (replicated from a central management server) and
buffers its accounting data before pushing it back to the management
server. I have tried two different methods, but none fully satisfied
me so far.

- First method uses "buffered-sql" and two sql modules: the first one
points to local database and is used for auth, the other points to
management server and is used by buffered-sql for accounting. This
works very well except for one thing - by design, if the management
sql server is unavailable for some reason, freeradius will refuse to
launch. It should not be an issue in 99% of the cases but still bugs
me a little bit.

- Second method uses a cron'd "radsqlrelay" and "sql_log". It will
accept to launch regardless of the status of management server, but in
return it is much less smarter on the SQL part due to its inability
get feedback from the sql server at the time the query is written (it
basically cant fallback on an INSERT should an UPDATE fail due to
non-existing record).

On many aspects method #1 is better, but I would like to find a way to
make the connection to management server optional at start-up, as I in
my case accounting is secondary and should not be interfering with
auth.

Thanks in advance for your help,

Yann