perfsonar development work

[Loukik Kudarimoti <>]

Jeff W. Boote wrote:
> Roman Lapacz wrote:
> > Implemented. Available in SVN (trunk).
>
> You implemented the units for the 'value' field of the datum, but not 
> the timeValue.
>
> This is another area where consistency will be important across 
> multiple data types. There will be other 'datum' types that have more 
> than one 'value' in the result datum.
>
> I would suggest that 'unit' is too generic of a name in the key. You 
> need to tie it more closely to the name of the field in the datum that 
> is being returned. In this case for example: 'valueUnit'. Then, you 
> can specify the time unit using 'timeValueUnit'. And it is clear for 
> any other datum fields how this would progress.
I agree.

Thinking more about it, if units for' bits per second' is bps, then 
units for 'bytes per second' would be Bps. There can be a bit 
misleading. To be on the safe side, my suggestion would be that 
perfSONAR by default uses 'bits per second' and 'bytes per second' or 
'octets per second'.

> I am curious why it is not sufficient to return the 'Units' in the 
> metadata of the response instead of including it in every single 
> datum... (I don't really care that much, but it seems like it would be 
> nice to have that factored out and that it really could be one of the 
> parameters of the response metadata.)
This in my opinion causes uncertainty for the user of nmwg schemas. It 
should be possible to specify the units of the datum in one place only 
for all incarnations of the nmwg schema. Otherwise, the schema becomes 
inherently unstable as same information is allowed to be present in two 
places.

If the question is whether it should be in metadata or it should be in 
datum, I would prefer it to be in datum. From the message size point of 
view, it wouldn't make a huge impact but on the other hand it would 
definitely allow situations where different datum in the same response 
have different units.

Regards,
Loukik
> jeff
>
> > Example of metadata configuration file:
> >
> > <nmwg:store >
> >
> >    <nmwg:metadata id="meta1">
> >        ....
> >    </nmwg:metadata>
> >
> >    <nmwg:data id="data1" metadataIdRef="meta1">
> >        <nmwg:key>
> >            <nmwg:parameters>
> >                <nmwg:parameter 
> > name="file">/rrd/test/test.rrd</nmwg:parameter>
> >                <nmwg:parameter name="dataSource">ds0</nmwg:parameter>
> >                <nmwg:parameter name="unit">bps</nmwg:parameter>
> >            </nmwg:parameters>
> >        </nmwg:key>
> >    </nmwg:data>
> >
> > </nmwg:store>
> >
> >
> >
> >
> > Example of response if the unit is specified in the key:
> >
> >
> > <nmwg:message>
> >   <nmwg:metadata id="meta1">
> >      ....
> >   </nmwg:metadata>
> >   <nmwg:data id="localhost.27b055c9:10cf803512a:-7fde" 
> > metadataIdRef="meta1">
> >      <nmwg:datum timeValue="1121558400" value="189.25857952114652" 
> > valueUnits="bps" />
> >      <nmwg:datum timeValue="1121644800" value="157.6300922870065" 
> > valueUnits="bps" />
> >      <nmwg:datum timeValue="1121731200" value="341.2686134412051" 
> > valueUnits="bps" />
> >      <nmwg:datum timeValue="1121817600" value="376.50555043698813" 
> > valueUnits="bps" />
> >      <nmwg:datum timeValue="1121904000" value="320.4919869209144" 
> > valueUnits="bps" />
> >   </nmwg:data>
> > </nmwg:message>
> >
> >
> >
> > Example of response if the unit is not specified in the key:
> >
> > <nmwg:message>
> >   <nmwg:metadata id="meta1">
> >      ....
> >   </nmwg:metadata>
> >   <nmwg:data id="localhost.-3e0ab627:10cf7f78557:-7fdf" 
> > metadataIdRef="meta1">
> >      <nmwg:datum timeValue="1121558400" value="189.25857952114652" 
> > valueUnits="unknown" />
> >      <nmwg:datum timeValue="1121644800" value="157.6300922870065" 
> > valueUnits="unknown" />
> >      <nmwg:datum timeValue="1121731200" value="341.2686134412051" 
> > valueUnits="unknown" />
> >      <nmwg:datum timeValue="1121817600" value="376.50555043698813" 
> > valueUnits="unknown" />
> >      <nmwg:datum timeValue="1121904000" value="320.4919869209144" 
> > valueUnits="unknown" />
> >   </nmwg:data>
> > </nmwg:message>
> >
> >
> >
> > Roman
> >
> >
> >
> >
> >
> >
> >
> >
> > > Loukik.
> > >
> > > > Roman
> > > >
> > > >
> > > >
> > > > > Loukik.
> > > > >
> > > > > > <nmwg:store>
> > > > > >
> > > > > >    <nmwg:metadata id="meta1">
> > > > > >        ....
> > > > > >    </nmwg:metadata>
> > > > > >
> > > > > >    <nmwg:data id="data1" metadataIdRef="meta1">
> > > > > >        <nmwg:key>
> > > > > >            <nmwg:parameters>
> > > > > >                <nmwg:parameter 
> > > > > > name="file">/test.rrd</nmwg:parameter>
> > > > > >                <nmwg:parameter 
> > > > > > name="dataSource">ps0</nmwg:parameter>
> > > > > >                <nmwg:parameter name="unit">bps</nmwg:parameter>
> > > > > >            </nmwg:parameters>
> > > > > >        </nmwg:key>
> > > > > >    </nmwg:data>
> > > > > >
> > > > > > </nmwg:store>
> > > > > >
> > > > > >
> > > > > >
> > > > > > Roman
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > Loukik Kudarimoti wrote:
> > > > > >
> > > > > > > [forgot to cc perfsonar-dev]
> > > > > > >
> > > > > > > ------------------------------------------------------------------------ 
> > > > > > >
> > > > > > >
> > > > > > > Subject:
> > > > > > > units expected from RRD MA
> > > > > > > From:
> > > > > > > Loukik Kudarimoti 
> > > > > > > <>
> > > > > > > Date:
> > > > > > > Thu, 10 Aug 2006 11:58:25 +0100
> > > > > > > To:
> > > > > > > Vedrin Jeliazkov 
> > > > > > > <>
> > > > > > >
> > > > > > > To:
> > > > > > > Vedrin Jeliazkov 
> > > > > > > <>
> > > > > > > CC:
> > > > > > > Andreas Hanemann <>, Roman Lapcz 
> > > > > > > <>
> > > > > > >
> > > > > > >
> > > > > > > Hi Vedrin and Andreas,
> > > > > > >
> > > > > > > I have a query about the units that you assume you are getting 
> > > > > > > from RRD MA. Basically, the response from RRD MA is as below:
> > > > > > >
> > > > > > >
> > > > > > >  <nmwg:data id="localhost.7e5caec1:10cf76b6c9d:-7fdf" 
> > > > > > > metadataIdRef="meta1">
> > > > > > >     <nmwg:datum timeValue="1121558400" 
> > > > > > > value="189.25857952114652" />
> > > > > > >     <nmwg:datum timeValue="1121644800" value="157.6300922870065" />
> > > > > > >     <nmwg:datum timeValue="1121731200" value="341.2686134412051" />
> > > > > > >     <nmwg:datum timeValue="1121817600" 
> > > > > > > value="376.50555043698813" />
> > > > > > >     <nmwg:datum timeValue="1121904000" value="320.4919869209144" />
> > > > > > >  </nmwg:data>
> > > > > > >
> > > > > > >
> > > > > > > It doesn't say whether the value is in bits per second, Mbits 
> > > > > > > per second or bytes per second. What do you assume the unit to 
> > > > > > > be in? do you think it would be better if the response 
> > > > > > > explicitly mentioned the units and also the timeType?
> > > > > > >
> > > > > > > Thanks,
> > > > > > > Loukik.