perfsonar development work

["Jeff W. Boote" <>]

Vedrin Jeliazkov wrote:
> Hi,
>
> Nina and myself agree that:
>
> - 'unit' is too generic and calling it <*>valueUnit (as suggested by Jeff)
> would be better;
>
> - it's preferrable to have <*>valueUnit in datum (as suggested by Loukik),
> rather than in metadata;

That is fine. It just seems wasteful to repeat a field like that in every single 
datum when it is common across the full set of data. As I said before, I don't 
feel strongly about it.

> We also feel that opening the door for free text content of <*>valueUnit could
> quickly lead to a multitude of variants for a given unit name in different
> service instances. It would be much better if the allowed units are well
> defined, known by clients and enforced by respective services in some way. We
> would very much like to avoid the possibility to have simultaneously:
>
> b/s
> bit/sec
> bits/sec
> bits per second
> etc...

I agree. For many of the units there are ISO (or at least SI) standards in 
place. (For time units for example.) We should use them when we can. And for the 
others we should make very sure that we have looked. One good place to start is:

http://en.wikipedia.org/wiki/SI
http://en.wikipedia.org/wiki/Binary_prefix

And, as much as we might think it is confusing. The most common specification of 
bytes vs bits out there is B vs b. We should stay consistent with the rest of 
the world here.

> And last, but not least, maybe it would be better to have bytes per second
> (instead of bits per second) in the default rrd-database_TEST.xml, because
> data sources reporting bytes seem to be more common.

We should stay consistent with the default units of the SNMP mib value - which I 
believe is octets (bytes) in this case.

In general, I don't think we should do units conversion unless it is somehow 
requested. (Laziness is a virtue in programming. ;) )

jeff