Facilities > VLA > Data Processing > Pipeline > Known Issues

Known Issues

by Drew Medlin last modified Apr 18, 2017

About this Page

This page describe issues that are known to either cause the pipeline to fail mid-process, causing the scripts to exit to the CASA prompt or the unexpected exiting of CASA itself, or to cause problems for calibration quality. These failures result in little or no calibration (and possible corruption of the MS in some cases).

Last update: 2015-02-26.

 

General Issues

The issues described here may affect any version of the VLA CASA Calibration pipeline or any version of CASA. Older datasets may go through the pipeline without issue, but we cannot guarantee this. Please note that all testing of the pipeline is currently performed on RedHat Enterprise Linux version 5.x and, more recently, version 6.x.

 

Testdelay.k does not exist

The symptom is the pipeline fails to complete and the last line in the casa log file is:

INFO    gaincal::::casa Exiting script: Table testdelay.k does not exist

This may be caused by the pipeline finding no unflagged data on the delay calibrator, causing all subsequent calibration steps to fail. You may still be able to calibrate these data by hand or with the pipeline by selecting a different field as the delay calibrator, as described here.

Integrated Pipeline Restoration Flagging failure in CASA 4.5.3

Due to an omission in hif_restoredata, CASA will give a SEVERE alert about a data shape mismatch between the final flag version and the MS created during the restore process, causing a failure to apply the final flag version saved. The solution is to create the MS again using hifv_importdata before running the restore script. Editing casa_piperestorescript.py to reference the MS instead of the SDM-BDF will be needed in this case as well. Detailed instructions to follow.

 

CASA 4.2 / Pipeline 1.3.x

 

Failure with: 'Nonetype' object has no attribute 'keys'

This affects pipeline versions 1.3.0 and 1.3.1 for users with CASA 4.2.x. The symptom is the termination of the pipeline after a call to setjy with the following in the CASA log file:

INFO  setjy::::casa  Exiting script: 'NoneType' object has no attribute 'keys'

This is caused when the secondary calibrator is the same source as the flux calibrator and this is the only calibrator source. The pipeline finds no secondary calibrator onto which flux densities may be transferred. A future update to the script should resolve this issue. If a fixed update is not currently released, please contact us via the Pipeline Department of the Helpdesk: a test version may be available with the corrections needed to handle this specific failure.

Segmentation fault during plotting

The current release of the VLA CASA Calibration Pipeline, version 1.2.0, is compatible only with CASA 4.1. However, some users have installed CASA 4.2 (or newer) on the same machine that already has CASA 4.1 installed. There are some library incompatibilities between these two versions of CASA that may cause the pipeline to fail with a segmentation fault, usually during a call to produce plots. A solution to this is to edit the pipeline scripts to comment out all plotting executions and run the pipeline in CASA 4.1. Once the pipeline completes, use CASA 4.2 to create the desired plots. We are currently working on an updated version of the scripted pipeline that is compatible with CASA 4.2, but there is no ETA for release at this time.

 

CASA 4.1 / Pipeline 1.2.x

 

MS creation fails for data taken on/after 2014-11-06

This issue affects only data taken on or after 2014-11-06 and those running CASA 4.1.x and the CASA 4.1 compatible version of the pipeline scripts. This is due to an update in MCAF that added the use of the scan intent "SYSTEM_CONFIGURATION" for setup scans in place of the "UNSPECIFIED" scan intent. The symptom of this issue is the failure to create a MS while running the EVLA_pipe_import.py part of the scripts.

To resolve this issue, an edit may be made to the "EVLA_pipe_import.py" script. After the first if statement in this script, find the line:

logprint ("Creating measurementset", logfileout='logs/import.log')

Just under this line, add the following text:

os.chdir(SDM_name)
os.system("sed -i 's/SYSTEM_CONFIGURATION/UNSPECIFIED/g' Scan.xml")
os.chdir("..")

Be sure to match the indentation of the line just above as well as below as well as leaving the space before the next line that sets the default for the importevla task.

This issue will affect all users with CASA 4.1.x and data taken on or after 2014-11-06 even if the pipeline scripts are not used. One alternate solution is to edit the Scan.xml file in the SDM-BDF to replace scan intents of "SYSTEM_CONFIGURATION" with "UNSPECIFIED".

 

Mac OS X Specific Issues

 

Missing Libraries

For some installations of CASA 4.1 on Mac OS X, there may be missing third party libraries which are needed by some parts of the pipeline. Known missing items include:

"libdb.so" or "libdb-4.3.so"

"_bsddb"

Currently, there are no known resolutions if either of these libraries are not found when called by the pipeline. A workaround for this issue is to use a Linux machine or use the NRAO's computing resources remotely. A future release of CASA for Mac OS X should resolve these issues, but there is currently no CASA 4.2 compatible version of the scripted pipeline. However, we are currently working on an updated version of the scripted pipeline that is compatible with CASA 4.2. There is no ETA for this upcoming release at this time.

 

Issues not covered here

If you are experiencing issues running the pipeline that cause a failure to complete or if you have questions about the pipeline, please contact us via the Pipeline Department of the NRAO Helpdesk.