Package ClusterShell :: Module Task

Module Task

ClusterShell Task module.

Simple example of use:

>>> from ClusterShell.Task import task_self, NodeSet
>>>  
>>> # get task associated with calling thread
... task = task_self()
>>> 
>>> # add a command to execute on distant nodes
... task.shell("/bin/uname -r", nodes="tiger[1-30,35]")
<ClusterShell.Worker.Ssh.WorkerSsh object at 0x7f41da71b890>
>>> 
>>> # run task in calling thread
... task.run()
>>> 
>>> # get results
... for output, nodelist in task.iter_buffers():
...     print '%s: %s' % (NodeSet.fromlist(nodelist), output)
...

Classes

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TaskException
Base task exception.

TaskError
Base task error exception.

TimeoutError
Raised when the task timed out.

AlreadyRunningError
Raised when trying to resume an already running task.

TaskMsgTreeError
Raised when trying to access disabled MsgTree.

Task
The Task class defines an essential ClusterShell object which aims to execute commands in parallel and easily get their results.

Functions

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_getshorthostname()
Get short hostname (host name cut at the first dot)

source code

task_self(defaults=None)
Return the current Task object, corresponding to the caller's thread of control (a Task object is always bound to a specific thread).

source code

task_wait()
Suspend execution of the calling thread until all tasks terminate, unless all tasks have already terminated.

source code

task_terminate()
Destroy the Task instance bound to the current thread.

source code

task_cleanup()
Cleanup routine to destroy all created tasks.

source code

Variables

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__package__ = 'ClusterShell'

Function Details

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task_self(defaults=None)

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Return the current Task object, corresponding to the caller's thread of control (a Task object is always bound to a specific thread). This function provided as a convenience is available in the top-level ClusterShell.Task package namespace.

task_wait()

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Suspend execution of the calling thread until all tasks terminate, unless all tasks have already terminated. This function is provided as a convenience and is available in the top-level ClusterShell.Task package namespace.

task_terminate()

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Destroy the Task instance bound to the current thread. A next call to task_self() will create a new Task object. Not to be called from a signal handler. This function provided as a convenience is available in the top-level ClusterShell.Task package namespace.

task_cleanup()

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Cleanup routine to destroy all created tasks. This function provided as a convenience is available in the top-level ClusterShell.Task package namespace. This is mainly used for testing purposes and should be avoided otherwise. task_cleanup() may be called from any threads but not from a signal handler.