Can't load data by using channelarchiver.Archiver

[yugangzhang]

Here is my code:

from channelarchiver import Archiver
start_time, end_time = '2017-06-04 09:00', '2017-06-04 9:20'  
pv  = 'SR:C03-BI{DCCT:1}I:Real-I'  #test pv for accelerator
pv ='XF:11IDA-UT{Cryo:1}T:05-I'    #test pv for xf11id
### xf11id data archiver
archiver =  Archiver('http://xf11id-ca.cs.nsls2.local/cgi-bin/ArchiveDataServer.cgi')  
# accelerator server
#archiver = Archiver('http://xf11id-ca.cs.nsls2.local:17668/retrieval/bpl')

When do

res = archiver.get(pv, start_time, end_time, scan_archives= True, limit=None, interpolation='raw')

I got

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-20-e4b84f6afa43> in <module>()
----> 1 res = archiver.get(pv, start_time, end_time, scan_archives= True, limit=None, interpolation='raw')

/opt/conda_envs/analysis/lib/python3.5/site-packages/channelarchiver/channelarchiver.py in get(self, channels, start, end, limit, interpolation, scan_archives, archive_keys, tz)
    213                                         start_sec, start_nano,
    214                                         end_sec, end_nano,
--> 215                                         limit, interpolation)
    216             for archive_data in data:
    217                 channel_data = self._parse_values(archive_data, tz)

/opt/conda_envs/analysis/lib/python3.5/xmlrpc/client.py in __call__(self, *args)
   1090         return _Method(self.__send, "%s.%s" % (self.__name, name))
   1091     def __call__(self, *args):
-> 1092         return self.__send(self.__name, args)
   1093 
   1094 ##

/opt/conda_envs/analysis/lib/python3.5/xmlrpc/client.py in __request(self, methodname, params)
   1424 
   1425         request = dumps(params, methodname, encoding=self.__encoding,
-> 1426                         allow_none=self.__allow_none).encode(self.__encoding, 'xmlcharrefreplace')
   1427 
   1428         response = self.__transport.request(

/opt/conda_envs/analysis/lib/python3.5/xmlrpc/client.py in dumps(params, methodname, methodresponse, encoding, allow_none)
    949         m = Marshaller(encoding, allow_none)
    950 
--> 951     data = m.dumps(params)
    952 
    953     if encoding != "utf-8":

/opt/conda_envs/analysis/lib/python3.5/xmlrpc/client.py in dumps(self, values)
    499             for v in values:
    500                 write("<param>\n")
--> 501                 dump(v, write)
    502                 write("</param>\n")
    503             write("</params>\n")

/opt/conda_envs/analysis/lib/python3.5/xmlrpc/client.py in __dump(self, value, write)
    521             # for the p3yk merge, this should probably be fixed more neatly.
    522             f = self.dispatch["_arbitrary_instance"]
--> 523         f(self, value, write)
    524 
    525     def dump_nil (self, value, write):

/opt/conda_envs/analysis/lib/python3.5/xmlrpc/client.py in dump_nil(self, value, write)
    525     def dump_nil (self, value, write):
    526         if not self.allow_none:
--> 527             raise TypeError("cannot marshal None unless allow_none is enabled")
    528         write("<value><nil/></value>")
    529     dispatch[type(None)] = dump_nil

TypeError: cannot marshal None unless allow_none is enabled

My questions are that is this a bug in channelarchiver.py? Or I did not use the correct server for xf11id data achiever? Also, can someone tell me the server for accelerator data achiever? We also want to know the beam current.

Thanks!

[ghost]

channelarchiver uses XMLRPC to communicate. You need to add allow_none=True in the xmlrpc client archiver uses, I don't think channelarchiver exposes this feature ( I might be wrong, I didn't look into the api in depth). Your issue seems like you're getting None as a response. This can mean your archiver might not be responsive or you are searching for something that doesn't exist. I would talk to someone from accelerator controls and your beamline's control engineer to find out the addresses for both archivers you'd like to access. Once you verify all the addresses+your query params and the issue persists, we can look into it as a software related bug.

[klauer]

What happens if you remove limit=None from the parameters you're sending?

[yugangzhang]

@arkilic The function doesn't have allow_none option

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-23-7ee841f76089> in <module>()
      1 res = archiver.get(pv, start_time, end_time, scan_archives= True, limit= None, 
----> 2                    allow_none=True, interpolation='raw')

TypeError: get() got an unexpected keyword argument 'allow_none'

[ghost]

Yes that's not what I meant. Did you try what @klauer ask you to do?

[yugangzhang]

@klauer when remove limit= None, the function doesn't raise error, but the output is wrong

pv = 'XF:11IDA-OP{Mir:HDM-Ax:P}Pos-I'
res = archiver.get(pv, start_time, end_time, scan_archives= True, interpolation='raw')

I got

Out[35]:
ChannelData(
    values=[-28],
    times=[datetime.datetime(2017, 4, 24, 2, 0, 41, 717345, tzinfo=<DstTzInfo 'America/New_York' EDT-1 day, 20:00:00 DST>)],
    statuses=[0],
    severities=[0],
    units='urad',
    data_type=3,
    elements=1,
    display_limits=Limits(low=0.0, high=0.0),
    warn_limits=Limits(low=0.0, high=0.0),
    alarm_limits=Limits(low=0.0, high=0.0),
    display_precision=2,
    archive_key=47418,
    interpolation=0
)

We know that the values of that PV (mirror pitch encoder) should change a lot in range of (-1820~-1850)and should not be that only one value (-28).

[ghost]

Are you sure the PV is what you think it is or is there an offset somewhere? Try to get a different time range.

[yugangzhang]

Yes. I tried different time and got the same one value (-28). Actually, I also tried different PV, and it always gave me one value.

[ghost]

Are you sure you have the right address for the archiver? Can you try it with a different address (even a bogus one)?

[ghost]

bump @yugangzhang