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

[Marco Chiappero]

Hi Arjen,
sorry for my late reply, it's been a really hard work week.


Arjen de Korte wrote:
> I very much like the basic concept behind this, this is certainly worth 
> investigating further. I would prefer to make this a separate driver 
> (proposal, netnsm-ups) instead though. The reason is that you could 
> follow the same approach using SNMP (instead of XML) from the UPS, so a 
> more universal approach would be to connect to a snmp-ups or netxml-ups 
> driver on top of the driver being an NSM client.

Apart from the fact that I know nothing about SNMP, I like the separated 
driver approach too but it seems to me that the solution you are 
proposing aims to support single UPS setups only (we would need a single 
NSM client instead, creating connections to multiple NMC, on top of all 
netxml-ups/snmp-ups drivers that require management as part of a 
redundant setup). Sorry, I'm not sure I've fully understood your idea, 
please explain a little bit more how would you connect NSM and SNMP/XML 
driver and so on. Thank you.

> I'm also a little concerned about multiple instances of netxml-ups 
> connecting to the same NMC. Older NMC's probably will not be stable 
> enough with multiple clients querying the XML pages. Older 66102 and 
> 66103 NMC's simply don't have the horsepower needed to support multiple 
> XML clients.

As I own an old 66102 (technical level 02), I can do some testing about 
this, if needed. However I think that NMC buyers should already know its 
limits.

> An approach might be to start from the 'clone' driver and add the NSM 
> specific code to that. This would allow transparent copying of all 
> information of the underlying base driver (snmp-ups or netxml-ups) and 
> still be able to add the desired info for the outlets (which is really 
> neat of your solution).

This sounds similar to my idea now... I certainly need some more 
explanation.
BTW, does the SNMP protocol allow the same XML management functionality?

> Last, I'm not sure if having the LOCAL configuration is a good idea from 
> a support point of view. Only using the CENTRALIZED configuration would 
> result in fewer options needed in ups.conf, which is easier for system 
> administrators to setup.

For a single PSU computer - single UPS schema it could, maybe, be 
useful, but I mainly agree with you, even though you already have to 
specify nothing but the outlet for a CENTRALIZED configuration. Moreover 
upssched can be instead used, so not a big deal.

Thank you for your attention.


Regards,
Marco