Frequently Asked Questions

Version 5.4b
September 2004

http://ess.stsci.edu/products/opus/faq/opusfaq.html

Contents

• Introduction
• OPUS Installation
• OPUS Servers
• OPUS Sample Pipeline
• OPUS Process Manager
• OPUS Applications
• OPUS Process Resource Files
• OPUS Path files
• OPUS Observation Manager
• OPUS Tools
• OPUS Upgrade Information
• Glossary

E-mail Help

• What if I can't find my question in this FAQ?

Introduction

• What is OPUS?
• What is included in the OPUS System?
• What are the OPUS "Managers"?
• What is not included in the distribution?
• What does the OPUS Sample Pipeline demonstrate?
• Why can't I just use a shell script to tie my applications together?
• Why are multiple instances of applications important?
• How many steps can there be in the pipeline?
• What are paths?
• How does OPUS work?
• Wasn't OPUS developed for the HST project?
• Isn't OPUS too elaborate for a small mission?

OPUS Installation

• What are the system requirements for the OPUS system?
• How much disk space is required to install the OPUS system?
• Can I run OPUS on a network of computers?
• Does OPUS require special privileges to run?
• How do I obtain the OPUS system?
• Do I have to put the OPUS distribution in a specially named directory?
• How do I install the OPUS distribution?
• What do I do if the installation fails?
• How do I uninstall the OPUS distribution?
• How do I configure my accounts to run OPUS (and RSH/SSH)?
• What is the OPUS directory structure?
• What environment variables are required?
• How do I determine whether OPUS works on my system?
• Can I run the sample pipeline on a network of mixed Unix types?
• How do I upgrade my version of the OPUS distribution?
   

• OPUS Managers

• How do I install the OPUS Java Managers?
• What platforms can I run the managers on?
• How do I run the installers?
• What choices do I have?
• How do I use SFTP in the Managers ?
• Can I use SFTP with Java 1.3 ?
• Finally, how do I run the installed managers?

OPUS Servers

• What are the OPUS servers?
• What is meant by beta products?
• When must I use the servers?
• What are the advantages of running in CORBA mode?
• What are some possible disadvantages?
• Do I need special privileges to run the servers?
• How do I configure the servers ?
• How do I start and stop them?
• Why do I get a "Permission denied" error when I try to start the servers?
• What happens if a server crashes?
• What do I have to do before manually restarting the servers after a problem?
• Are the servers secure?
• What CORBA package does OPUS use?
• What enhancements can I expect to the servers in the future?

Sample Pipeline

• What does the sample pipeline do?
• How do I run the sample pipeline?
• How much disk space do I need to run the sample pipeline?
• Do I need a database to run the sample pipeline?
• Can I use the FITS files to do science?
• How does OPUS make things easier?
• What do I have to do to rerun the sample pipeline?
• What does it mean if a process is marked ABSENT on the PMG display, and what do I do?
• Why do some GIF images fail the KW step in the sample pipeline?
• How do I determine if the process status entry is created?
• How do I determine if the observation status entries are created?
• In what order are datasets processed in the pipeline?
• Can I run more than one conversion process (g2f) in the pipeline?
• How do I distribute processes over different machines?
• How do I bring up multiple instances of the pipeline?
• How do I determine if one of the processes has crashed?
• How do I know when the processing is complete?
• How do I turn the pipeline off?
• What happens if I run out of disk space?
• I can't find the output for this sample pipeline!
• How do I display the results to verify the operation?
• Why are the images in the FITS files monochromatic?
• How do I verify that the FITS files comply with the standard?
• Is there an easy way to list the keywords in a FITS file?
• Can OPUS do parallel processing?
• How do you make a process wait for the completion of two tasks?
• How can I run parallel pipelines (paths)?
• Does OPUS come with any other code samples ?

OPUS Process Manager

• What is the PMG?
• Do I need any software not provided on the OPUS CD to run the PMG?
• How do I start the Process Manager?
• What's the password dialog for?
• What is a process status entry?
• Can I modify the structure of a process status entry?
• How do I tell the PMG which paths to monitor?
• How do I select a new set of nodes?
• How do I start up a process?
• How do I remove a pending task?
• How then do I actually start the process?
• How do I terminate a running process?
• Can I suspend a specific process in the pipeline?
• How do I resume a suspended process?
• How do I bring all processes down?
• My Selections are disappearing!
• What is a pipeline?
• How do I define a pipeline?
• How do I create a pipeline file?
• Can I save the pipeline definition?
• How do I load a saved pipeline definition?
• How do I start the pipeline?
• OK. I did that, but nothing happened! Now what?
• How do I remove a path from my PMG display?
• How do I remove a column from the PMG?
• Can I add a path to the PMG display?
• How do I get help to work?
• How do I know if a task exits abnormally?
• What do I do if a process exits abnormally?
• How do I view the log file for a particular process?
• How do I save my preferences?
• Can I change the default display font?
• What is in the PMG.ini file?
• How can I restrict the number of processes in a pipeline?
• I got a "Communication failure !" error. What's this ?
• Can I add functionality to the managers?

OPUS Applications

• What are the advantages of using OPUS?
• What kind of processes can be run in the pipeline?
• Can a script read from STDIN (standard input)?
• Can I use command line arguments for my tasks?
• How are the values of environment variables set?
• What is the difference between an external and an internal poller?
• How do I create a C++ internal poller ?
• Can I create an internal poller in a language besides C++ ?
• How do I add a processing step to a pipeline?
• Are there any limitations on naming a new task?
• What are some of the common gotchas I should beware of when I write my OPUS tasks?
• What kind of message reporting does OPUS provide?

Process Resource Files

• What is a process resource file?
• What is contained in a process resource file?
• What's an easy way to view the process resource file?
• What is the complete format of a line in the process resource file?
• What are the minimum keywords required in a process resource file?
• Which process resource file keywords are reserved or have specific uses?
• Where will I find process resource files in the OPUS directory tree?
• What types of pipeline triggers can be set up in a process resource file?
• How do I set up a process with an OSF trigger?
• How do I set up a process to trigger on the existence of a certain file?
• How do I set up a relative time trigger?
• How do I set up a process to trigger once a day?
• How do I set up a process to trigger once an hour starting at some point ?
• How can I use the exit status of a process to trigger pipeline actions?
• Ok, but what if my external poller processes more than one item per event ?
• Can a process with a file trigger perform an arbitrary task upon successful completion ?
• How can process resource keyword values be obtained by a script?
• Can keyword values be obtained from files other than the process resource file?
• What are the differences between path files and process resource files?
• Can resource file parameters refer to a specific path?
• How do you decide whether to put a keyword value in a path file or in a process resource file?
• Can I give a keyword different values for the same process running in different paths?
• Can process resource file keyword values come from the environment ?
• Are process resource file keyword names case sensitive?
• Can OPUS protect against running out of disk space?
• So what do I do if a process is in this "iowait" state?

OPUS Path files

• What is a path?
• Where do I find the path files in the OPUS directory tree?
• How do I find out what directories are used in a path?
• What are the rules for making a path file?
• Are things other than directories in a path file?
• Do the path file variables supersede process resource file variables?
• Can path file variables refer to environment variables ?
• How do path names get translated?
• Can one pipeline feed data into another pipeline?
• How does a task "inquire" for a path file value?
• What keywords are required in the path file?

Observation Manager

• What are observations?
• What is the OMG?
• Do I need any software not provided on the OPUS CD to run the OMG?
• How do I start the Observation Manager?
• What is the password dialog for?
• What happens if I am properly authorized?
• How do I select a path?
• Ugly! How do I get rid of the dots?
• How can I subdivide a display field?
• How do I save my preferences?
• Does the OMG support the OAPI?
• What is an Observation Status File (OSF)?
• Can I modify how an Observation Status File is structured?
• How do I create an OSF?
• How do I update an OSF?
• How do I test for an OSF?
• Can I display auxiliary files related to an OSF?
• How do I read the time stamp on an Observation Status File?
• Can I monitor more than one pipeline or path at a time?
• Can I stop a specific observation from processing further?
• How do I tell if an observation has encountered a processing problem?
• Is there a way to determine the meaning of a status of an observation?
• How do I change the status of one or more observations?
• Can I change the frequency at which the display is updated?
• Can I filter the types of OSFs that are displayed?
• Can I copy part of the OSF listing to the system clipboard?
• How do I change the colors used on the display?
• What controls the order of the observations in the OMG?
• Is there any limit on the length of observations "name"?
• What is the pipeline stage file?
• I got a "Communication failure" error. What's this ?

Glossary

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