11.10. pegasus-exitcode

Used post-job to check the stdout/stderr for errors

pegasus-exitcode [-h][-r rv][-n][-s msg][-f msg] job.out

11.10.1. Description

pegasus-exitcode is a utility that examines the STDOUT of a job to determine if the job failed, and renames the STDOUT and STDERR files of a job to preserve them in case the job is retried.

Pegasus uses pegasus-exitcode as the DAGMan postscript for jobs submitted via Globus GRAM. This tool exists as a workaround to a known problem with Globus and HTHTCondor-G where the exitcodes of GRAM jobs are not returned. This is a problem because Pegasus uses the exitcode of a job to determine if the job failed or not.

In order to get around the exitcode problem, Pegasus can wrap GRAM jobs with Kickstart, which records the exitcode of the job in an XML invocation record, which it writes to the job’s STDOUT. The STDOUT is transferred from the execution host back to the submit host when the job terminates. After the job terminates, DAGMan runs the job’s postscript, which Pegasus sets to be pegasus-exitcode. pegasus-exitcode looks at the invocation record generated by kickstart to see if the job succeeded or failed. If the invocation record indicates a failure, then pegasus-exitcode returns a non-zero result, which indicates to DAGMan that the job has failed. If the invocation record indicates that the job succeeded, then pegasus-exitcode returns 0, which tells DAGMan that the job succeeded.

In addition, clustered jobs executed with pegasus-cluster or pegasus-mpi-cluster will have a [cluster-summary] record in their STDOUT. pegasus-exitcode can examine these records to determine if any of the tasks in the clustered job failed.

pegasus-exitcode performs several checks (some optional) to determine whether a job failed or not. These checks include:

  1. Is the HTCondor exitcode non-zero? If so, then the job failed.

  2. Is STDOUT empty? If it is empty, then the job failed.

  3. Are there any failure messages in the STDOUT or STDERR? If so, the job failed.

  4. Are all of the success messages in the STDOUT or STDERR? If not, then the job failed.

  5. Does the [cluster-summary] record indicate that the job was successful. If not, then the job failed.

  6. Are there any <status> tags with a non-zero value? If there are, then the job failed. Note that, if this is a clustered job, there could be multiple <status> tags, one for each task. If any of them are non-zero, then the job failed.

  7. Is there at least one <status> tag with a zero value? There must be at least one successful invocation or the job has failed.

In addition, pegasus-exitcode allows the caller to specify the exitcode returned by HTCondor using the –return argument. This can be passed to pegasus-exitcode in a DAGMan post script by using the $RETURN variable. If this value is non-zero, then pegasus-exitcode returns a non-zero result before performing any other checks. For GRAM jobs, the value of $RETURN will always be 0 regardless of whether the job failed or not.

Below is a matrix of how the HTCondor exitcode are reconciled with an exitcode found in the kickstart records

kick-ec | -r | Reason 0 | 0 | No error 1 | 0 | Task failed 0 | 1 | HTCondor failed it 1 | 1 | Task failed

For jobs launched without kickstart (–no-invocations flag) pegasus-exitcode does not fail a job, if there is empty stdout

In addition to checking the success/failure of a job, pegasus-exitcode also renames the STDOUT and STDERR files of the job so that if the job is retried, the STDOUT and STDERR of the previous run are not lost. It does this by appending a sequence number to the end of the files. For example, if the STDOUT file is called “job.out”, then the first time the job is run pegasus-exitcode will rename the file “job.out.000”. If the job is run again, then pegasus-exitcode sees that “job.out.000” already exists and renames the file “job.out.001”. It will continue to rename the file by incrementing the sequence number every time the job is executed.

11.10.2. Options

-h; –help

Prints a usage summary with all the available command-line options.

-r rv; –return rv

Return value reported by DAGMan. This can be specified in the DAG using the $RETURN variable. If this is non-zero, then pegasus-exitcode immediately fails with a non-zero return value itself. If it is zero, then just rotate the file and don’t check for proper kickstart output. This option can be used in cases where kickstart cannot be used (such as pegasus-create-dir) to enable file rotation.

-n; –no-rename

Don’t rename job.out and job.err to .out.XXX and .err.XXX. This option is used primarily for testing.

-N; –no-metadata

Disable generation of metadata file after parsing of kickstart records.

-I; –no-invocations

Do not check for invocation records(present in kickstart output) output in the job.out file

-f msg; –failure-message msg

Failure message to find in job stdout/stderr. If this message exists in the stdout/stderr of the job, then the job will be considered a failure no matter what other output exists. If multiple failure messages are provided, then none of them can exist in the output or the job is considered a failure.

-s msg; –success-message msg

Success message to find in job stdout/stderr. If this message does not exist in the stdout/stderr of the job, then the job will be considered a failure no matter what other output exists. If multiple success messages are provided, then they must all exist in the output or the job is considered a failure.

-l filename; –log filename

Name of the common log file in which stdout/stderr will be redirected.