[Nut-upsdev] MGE NMC and NutShutdownModule (and other stuff)

[Marco Chiappero]

Arjen de Korte ha scritto:
> Citeren Marco Chiappero <marco at absence.it>:
> More or less, yes. In order to limit the number of variables that need 
> to be set, I would limit the configuration to LOCAL only and provide 
> some sensible defaults for the shutdown delay and shutdown timer 
> however. By explicitly setting these in the driver, this will make 
> helping people setting this up easier (otherwise it would require 
> setting up both the NMC and NUT).

Uhm, I feel it's much better to offer a user choice. The main reason is 
that we already have reasonable default settings, the NMC ones (which 
are probably corrected during initial installation and setups, if 
needed). So, a basic configuration would just require the ups address 
and the outlet. On the other side it can also be useful to use specific 
local settings providing at list the shutdown delay. The driver 
configuration it's already simple enough for both "lazy" and "advanced" 
users, leaving some freedom of choice; moreover preserving the Eaton 
behavior imho is preferrable. For example, due to cable routing 
problems, I indeed use both LOCAL and CENTRALIZED settings on different 
machines.
I still have to understand, instead, whether the ADMIN and USER settings 
have some implications on the type of messages sent through the NSM 
communication.

> Did you already try to connect multiple drivers yet? The NMC I'm using 
> (66102 / GA) seems to allow only a single TCP connected subscription 
> from any single IP. So if a driver is already connected, starting 
> another one will make the NMC disconnect the others that are connected 
> from the same IP.

Yes, I think you're right. I tried ones, and I sow that the NMC closes 
the second TCP connections immediately after reading the secret key. 
However I have to investigate whether the NMC takes into account the IP 
or the hostname to reject clones. I'll have a try in these days.

  While this makes perfect sense for machines that use
> an NSM client to shut them down, this bites us if we want to monitor all 
> outlets through multiple drivers in NUT.

Sorry, I'm not sure what you mean. I'm not experiencing any problem 
connecting to the NMC for both management and web pages at the same time 
from the same machine. On the other side connecting a single machine to 
different outlets from the same ups makes no sense. Is it right?
BTW, I saw that no authentication is required for all the data and 
management pages even though I enabled the authentication for every menu 
page. I don't know whether it's a bug in my own firmware or the 
authentication is used for the user web pages only by design. I have 
seen that it gets never used in the netxml-ups too. I haven't tried the 
auth+ssl configuration though.

> This problem popped up when I added monitoring of the connection state. 
> I added an automatic reconnection if the connection was lost. It took 
> only a few seconds for three NSM connected drivers (connected to the 
> main, outlet-1 and outlet-2) fighting for a subscription to confuse the 
> NMC enough to trigger a reset. Ouch! :-)

Three clients on the same machine using different outlets? With my code? 
Please, tell me exactly how to reproduce it.

However, if no problems occur, I think I'm going to write a mgensm or 
mgensm-ups driver that includes a nsm-xml.c parsing file, cloned from 
mge-xml.c. However we have to accurately choose what to parse (= what to 
expose as nut variable - I'd say the minimum -), and as I have a small 
MGE Evolution I can't say which kind of information the alarm messages 
contains in bigger UPSes. I see just AC presents / charging-discharging 
/ load / runtime messages and so on but maybe many other can be sent 
under certain circumstances on different UPSes; probably you and Arnaud 
can help a lot.
BTW, what about mapping System.Outlet[3].RunTimeToShutdown, 
System.Outlet[2].RunTimeToShutdown and System.RunTimeToShutdown to a 
outlet.runtime variable?

As soon as I have some working code and maybe manpage text, I'll attach 
the code for revision and correction. In the meantime let's continue 
talking here about problems, news or ideas. Ok?


Best regards,
Marco