How to configure processes, (and applications)

[Hal Snyder]

Anders Nygren <anders.nygren@REDACTED> writes:

> On Mon, 21 Feb 2005 22:35:59 +0500 (YEKT), Vladimir Sekissov
> <svg@REDACTED> wrote:
>> Good day,
>
> SNIP
>
>> 
>> IMHO this way is more verbose but more flexible than direct OTP
>> one(but compatible).
>> 
>> I can send you code if you want one.
>> 
> Hi
> I am not sure I completely understand what You are doing 
> but please send some code as this looks interesting.
>
> Does Your method also support configuration changes 
> while the system is running?

On a telephony platform we regularly have the following requirements:

- change config without restarting servers/nodes/processes

- change persists when things are restarted

- change is picked up when systems are replaced or added

Specifying configuration in config files or command line commits you
to real-time edits in the above cases.

So, is there a way to store things in a distributed, non-volatile,
scalable database (which is read-mostly, if you want to take advantage
of that property) in Erlang/OTP? Answer is yes, there is: mnesia.

There are bootstrap issues making sure OTP nodes all find each other
and sync up properly. See extra_db_nodes posting to this list, e.g.:

http://www.erlang.org/ml-archive/erlang-questions/200502/msg00176.html

Also with any replicated database, you will go nuts with
partition-and-reconnect unless you consider the requirements of the
situation and system topology during design.