[Serusers] Dispatcher and a dynamic list file

[Alistair Cunningham]

I'm looking for ideas on how to use the dispatcher module with a list 
file that is frequently updated by another process (specifically, it 
checks the availability of the remote machines, and also interacts with 
the heartbeat program).

In the past, I've always used an exec_dst() call to run an external 
program which does this, but would now like to migrate to using 
dispatcher for performance. If that's not possible, I'll go back to the 
old method.

I've considered adding a call to ds_select_dst() to call 
ds_destroy_list(); ds_load_list() on each request with file locking. It 
looks like it should work. Has anyone implemented this? Does it work? 
Does it have a significant impact on performance?

I'd also be open to having the other process write to a database table, 
which then SER reads. I'm not sure what's the best mechanism within SER 
to look up the table - perhaps avpops? I'd even be willing write a new 
module to do it - 'dispatcher_db' perhaps, but this wouldn't be in the 
short future.

-- 
Alistair Cunningham,
Integrics Ltd,
+44 (0)7870 699 479
http://integrics.com/