Dysco error when attempting to read MS

[mknapp55]

I get the error below when attempting to run a simple script that accesses a dysco compressed MS. I've used only Kern to install relevant packages (casacore, python-casacore, dysco). Is there a special installation order to get casacore/pyrap to work with dysco compressed files? I originally posted this issue to the dysco repo, but was advised to post it here instead.

  File "/usr/lib/python2.7/dist-packages/casacore/tables/table.py", line 375, in __init__
    Table.__init__(self, tabname, lockopt, opt)
RuntimeError: Table DataManager error: Data Manager class DyscoStMan is not registered
  Check (DY)LD_LIBRARY_PATH matches the libraries used during the build of DyscoStMan```

[gijzelaerr]

can you give me the simple script please.

[mknapp55]

https://github.com/lofar-astron/LOFAR-Contributions/blob/master/Maintained/plot_Ateam_elevation.py

[gijzelaerr]

can you supply the dysco compressed MS?

[gijzelaerr]

or give me small dysco compressed ms :)

[mknapp55]

I can't get basic access the the MS via casa (see below). I usually split large MSs via split() in casa - if there's another way to break out a small piece, let me know.

CASA <7>: listobs('L693114_SB079_uv.MS')
2019-04-02 15:29:49     SEVERE  listobs::ms::open       Exception Reported: Table DataManager error: Data Manager class DyscoStMan is not registered
2019-04-02 15:29:49     SEVERE  listobs::::     *** Error *** Table DataManager error: Data Manager class DyscoStMan is not registered
2019-04-02 15:29:49     SEVERE  ms::detached    ms is not attached to a file - cannot perform operation.
2019-04-02 15:29:49     SEVERE  ms::detached+   Call ms.open('filename') to reattach.
  Out[7]: False

I tried ms.open() and got the same error:

CASA <11>: ms.open('L693114_SB000_uv.MS')
2019-04-02 15:35:05     SEVERE  ms::open        Exception Reported: Table DataManager error: Data Manager class DyscoStMan is not registered
---------------------------------------------------------------------------
RuntimeError                              Traceback (most recent call last)

/home/mknapp/casa-release-4.6.0-el6/lib/python2.7/casapy.py in <module>()
----> 1
      2
      3
      4
      5

/home/mknapp/casa-release-4.6.0-el6/lib/python2.7/__casac__/ms.pyc in open(self, *args, **kwargs)
    405
    406         """
--> 407         return _ms.ms_open(self, *args, **kwargs)
    408
    409     def reset(self):

RuntimeError: Table DataManager error: Data Manager class DyscoStMan is not registered

[gijzelaerr]

i can't reproduce the error without a sample dysco compressed ms.

[mknapp55]

Here's a link to download one of the MSs. It's 2.4G, but I can't cut it down because I can't manipulate it in CASA.

[gijzelaerr]

i'll have a look when i find the time.

[gijzelaerr]

I can confirm this issue, looks like the dysco in KERN-5 is built against casacore < 3.0. Making a new package now which should solve the issue.

[gijzelaerr]

i've pushed a new dysco package, does this package solve your issues?

[mknapp55]

I used apt-get update to update dysco and casacore-dev, but still get the same error. Which versions should I have of those two packages? Are there other packages I need to upgrade? Or should I remove and reinstall the packages?

[gijzelaerr]

did you only run update? because that doesn't update the package, only the cache. I didn't push a new version of casacore-dev. What version of Dysco do you have now? It should be 1.2-1kern1

[mknapp55]

I removed and reinstalled dysco. It is 1.2-1kern1. I still get the same error.

sudo apt remove --purge dysco
sudo apt autoremove
sudo apt-get install dysco

[gijzelaerr]

bingo! This is actually an issue with the python-casacore package, which is still linked against casacore 2. Working on a fix.

[gijzelaerr]

this should be fixed in KERN-5 and KERN-dev now. Please update python-casacore to 3.0.0-1kern1 and dysco to 1.2.1kern1. Note that the dysco library/dev packages have been renamed. Please reopen this issue if this doesn't solve your issue.