[Nut-upsdev] upsd flapping in the breeze

[Arjen de Korte]

Citeren Daniel O'Connor <doconnor at gsoft.com.au>:

> I have had a long standing problem with NUT talking to 110V MGE UPSs on
> FreeBSD, I was recently investigating again and noticed that upsd seems
> overly noisy, eg..
>
> May  5 03:50:36 egbert upsd[96662]: UPS [ups1] data is no longer stale
> May  5 03:50:36 egbert upsd[96662]: Data for UPS [ups1] is stale -  
> check driver
> May  5 03:50:36 egbert upsd[96662]: UPS [ups1] data is no longer stale
> May  5 03:50:36 egbert upsd[96662]: Data for UPS [ups1] is stale -  
> check driver
> May  5 03:50:39 egbert upsd[96662]: UPS [ups1] data is no longer stale
> May  5 03:50:46 egbert upsd[96662]: Data for UPS [ups1] is stale -  
> check driver
> May  5 03:50:46 egbert upsd[96662]: UPS [ups1] data is no longer stale
> May  5 03:50:47 egbert upsd[96662]: Data for UPS [ups1] is stale -  
> check driver
> May  5 03:50:47 egbert upsd[96662]: UPS [ups1] data is no longer stale
> May  5 03:50:47 egbert upsd[96662]: Data for UPS [ups1] is stale -  
> check driver
> May  5 03:50:47 egbert upsd[96662]: UPS [ups1] data is no longer stale
> May  5 03:50:47 egbert upsd[96662]: Data for UPS [ups1] is stale -  
> check driver
> May  5 03:50:50 egbert upsd[96662]: UPS [ups1] data is no longer stale
>
> ie 5 messages per second! MAXAGE is 15 seconds, IMO it should be at _least_
> that time between complaints of staleness..

This has nothing to do with MAXAGE. This is the driver that is  
complaining about a lost connection to the UPS. The server can't do  
anything about that and only relays what it gets from the driver. As  
Arnaud has already mentioned, running the driver with debug level 3 or  
higher will tell you the reason why the server is logging these lines.  
In retrospect, it would have been better if it made a difference  
between the driver reporting this, or that the connection to the  
driver socket would be lost.

> Am I misunderstanding what MAXAGE does?

Probably not. In the old days, the server would run into staleness  
problems for the driver socket if driver authors wouldn't call  
dstate_dataok() frequent enough for the server to be happy. Now that  
the server solicits a response from drivers (PING) at least twice  
before declaring them stale, this really doesn't happen anymore for  
most drivers. Some are still taking way too much time in  
upsdrv_updateinfo(), which might lead to similar problems.

Best regards, Arjen
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