Globus::GRAM::JobManager - Base class for all Job Manager
scripts
$manager = new Globus::GRAM::JobManager($job_description);
$manager->log("Starting new operation");
$manager->nfssync($fileobj,$createflag);
$manager->respond($hashref);
$hashref = $manager->submit();
$hashref = $manager->poll();
$hashref = $manager->cancel();
$hashref = $manager->signal();
$hashref = $manager->make_scratchdir();
$hashref = $manager->remove_scratchdir();
$hashref = $manager->rewrite_urls();
$hashref = $manager->stage_in();
$hashref = $manager->stage_out();
$hashref = $manager->cache_cleanup();
$hashref = $manager->remote_io_file_create();
$hashref = $manager->proxy_relocate();
$hashref = $manager->proxy_update();
$scalar = $manager->pipe_out_cmd(@arglist);
($stderr, $rc) = $manager->pipe_err_cmd(@arglist);
$status = $manager->fork_and_exec_cmd(@arglist);
$manager->append_path($hash, $variable, $path);
$scalar = $manager->setup_softenv();
The Globus::GRAM::JobManager module implements the base behavior
for a Job Manager script interface. Scheduler-specific job manager scripts
must inherit from this module in order to be used by the job manager.
- $manager = Globus::GRAM::JobManager->new($JobDescription)
- Each Globus::GRAM::JobManager object is created by calling the constructor
with a single argument, a Globus::GRAM::JobDescription object containing
the information about the job request which the script will be modifying.
Modules which subclass Globus::GRAM::JobManager MUST call the
super-class's constructor, as in this code fragment:
my $proto = shift;
my $class = ref($proto) || $proto;
my $self = $class->SUPER::new(@_);
bless $self, $class;
- $manager->log($string)
- Log a message to the job manager log file. The message is preceded by a
timestamp.
- $manager->nfssync($object,$create)
- Send an NFS update by touching the file (or directory) in question. If the
$create is true, a file will be created. If it is
false, the $object will not be created.
- $manager->respond($message)
- Send a response to the job manager program. The response may either be a
hash reference consisting of a hash of (variable, value) pairs, which will
be returned to the job manager, or an already formatted string. This only
needs to be directly called by a job manager implementation when the
script wants to send a partial response while processing one of the
scheduler interface methods (for example, to indicate that a file has been
staged).
The valid keys for a response are defined in the RESPONSES
section.
- $manager->submit()
- Submit a job request to the scheduler. The default implementation returns
with the Globus::GRAM::Error::UNIMPLEMENTED error. Scheduler specific
subclasses should reimplement this method to submit the job to the
scheduler.
A scheduler which implements this method should return a hash
reference containing a scheduler-specific job identifier as the value of
the hash's JOB_ID key, and optionally, the a GRAM job state as the value
of the hash's JOB_STATE key if the job submission was successful;
otherwise a Globus::GRAM::Error value should be returned. The job state
values are defined in the Globus::GRAM::JobState module. The job
parameters (as found in the job rsl) are defined in
Globus::GRAM::Jobdescription object in
$self->{JobDescription}.
For example:
return {JOB_STATE => Globus::GRAM::JobState::PENDING,
JOB_ID => $job_id};
- $manager->poll()
- Poll a job's status. The default implementation returns with the
Globus::GRAM::Error::UNIMPLEMENTED error. Scheduler specific subclasses
should reimplement this method to poll the scheduler.
A scheduler which implements this method should return a hash
reference containing the JOB_STATE value. The job's ID can be accessed
by calling the
$self->{JobDescription}->jobid()
method.
- $manager->cancel()
- Cancel a job. The default implementation returns with the
Globus::GRAM::Error::UNIMPLEMENTED error. Scheduler specific subclasses
should reimplement this method to remove the job from the scheduler.
A scheduler which implements this method should return a hash
reference containing the JOB_STATE value. The job's ID can be accessed
by calling the
$self->{JobDescription}->jobid()
method.
- $manager->signal()
- Signal a job. The default implementation returns with the
Globus::GRAM::Error::UNIMPLEMENTED error. Scheduler specific subclasses
should reimplement this method to remove the job from the scheduler. The
JobManager module can determine the job's ID, the signal number, and the
(optional) signal arguments from the Job Description by calling it's
job_id(), signal(), and and signal_arg() methods,
respectively.
Depending on the signal, it may be appropriate for the
JobManager object to return a hash reference containing a JOB_STATE
update.
- $manager->make_scratchdir()
- Create a scratch directory for a job. The scratch directory location is
based on the JobDescription's scratch_dir_base() and
scratch_dir() methods.
If the scratch_dir() value is a relative path, then a
directory will be created as a subdirectory of
scratch_dir_base()/scratch_dir(), otherwise, it will be
created as a subdirectory of scratch_dir(). This method will
return a hash reference containing mapping SCRATCH_DIR to the absolute
path of newly created scratch directory if successful.
- $manager->make_scratchdir()
- Delete a job's scratch directory. All files and subdirectories of the
JobDescription's scratch_directory() will be deleted.
- $manager->make_scratchdir()
- Delete some job-related files. All files listed in the JobDescription's
file_cleanup() array will be deleted.
- $manager->rewrite_urls()
- Looks up URLs listed in the JobDescription's stdin() and
executable(), and replaces them with paths to locally cached
copies.
- $manager->stage_in()
- Stage input files need for the job from remote storage. The files to be
staged are defined by the array of [URL, path] pairs in the job
description's file_stage_in() and file_stage_in_shared()
methods. The Globus::GRAM::JobManager module provides an implementation of
this functionality using the globus-url-copy and globus-gass-cache
programs. Files which are staged in are not automatically removed when the
job terminates.
This function returns intermediate responses using the
Globus::GRAM::JobManager::response() method to let the job
manager know when each individual file has been staged.
- $manager->stage_out()
- Stage output files generated by this job to remote storage. The files to
be staged are defined by the array of [URL, destination] pairs in the job
description's file_stage_out() method. The Globus::GRAM::JobManager
module provides an implementation of this functionality using the
globus-url-copy program. Files which are staged out are not removed by
this method.
- $manager->cache_cleanup()
- Clean up cache references in the GASS which match this job's cache tag
.
- $manager->remote_io_file_create()
- Create the remote I/O file in the job dir which will contain the
remote_io_url RSL attribute's value.
- $manager->proxy_relocate()
- Relocate the delegated proxy for job execution. Job Managers need to
override the default if they intend to relocate the proxy into some common
file system other than the cache. The job manager program does not depend
on the new location of the proxy. Job Manager modules must not remove the
default proxy.
- $hashref = $manager->proxy_update();
- $manager->append_path($ref, $var, $path)
- Append $path to the value of
$ref->{$var}, dealing with the case where
$ref->{$var} is not yet defined.
- $manager->pipe_out_cmd(@arg)
- Create a new process to run the first argument application with the
remaining arguments (which may be empty). No shell metacharacter will be
evaluated, avoiding a shell invocation. Stderr is redirected to /dev/null
and stdout is being captured by the parent process, which is also the
result returned. In list mode, all lines are returned, in scalar mode,
only the first line is being returned. The line termination character is
already cut off. Use this function as more efficient backticks, if you do
not need shell metacharacter evaluation.
Caution: This function deviates in two manners from regular
backticks. Firstly, it chomps the line terminator from the output.
Secondly, it returns only the first line in scalar context instead of a
multiline concatinated string. As with regular backticks, the result may
be undefined in scalar context, if no result exists.
A child error code with an exit code of 127 indicates that the
application could not be run. The scalar result returned by this
function is usually undef'ed in this case.
- ($stder, $rc) = $manager->pipe_err_cmd(@arg)
- Create a new process to run the first argument application with the
remaining arguments (which may be empty). No shell metacharacter will be
evaluated, avoiding a shell invocation.
This method returns a list of two items, the standard error of
the program, and the exit code of the program. If the error code is 127,
then the application could not be run. Standard output is discarded.
- $manager->fork_and_exec_cmd(@arg)
- Fork off a child to run the first argument in the list. Remaining
arguments will be passed, but shell interpolation is avoided. Signals
SIGINT and SIGQUIT are ignored in the child process. Stdout is appended to
/dev/null, and stderr is dup2 from stdout. The parent waits for the child
to finish, and returns the value for the CHILD_ERROR variable as result.
Use this function as more efficient system() call, if you can do
not need shell metacharacter evaluation.
Note that the inability to execute the program will result in
a status code of 127.
- $manager->job_dir()
- Return the temporary directory to store job-related files, which have no
need for file caching.
- $manager->setup_softenv()
- Either add a line to the specified command script file handle to load the
user's default SoftEnv configuration, or create a custom SoftEnv script
and add commands to the specified command script file handle to load
it.
When returning from a job interface method, or when sending an
intermediate response via the response() method, the following hash
keys are valid:
- JOB_STATE
An integer job state value. These are enumerated in the
Globus::GRAM::JobState module.
- ERROR
An integer error code. These are enumerated in the
Globus::GRAM::Error module.
- JOB_ID
A string containing a job identifier, which can be used to
poll, cancel, or signal a job in progress. This response should only be
returned by the submit method.
- SCRATCH_DIR
A string containing the path to a newly-created scratch
directory. This response should only be returned by the
make_scratchdir method.
- STAGED_IN
A string containing the (URL, path) pair for a file which has
now been staged in. This response should only be returned by the
stage_in method.
- STAGED_IN_SHARED
A string containing the (URL, path) pair for a file which has
now been staged in and symlinked from the cache. This response should
only be returned by the stage_in_shared method.
- STAGED_OUT
A string containing the (path, URL) pair for a file which has
now been staged out by the script. This response should only be returned
by the stage_out method.