Parsl Task Submission

The Wrapper

• Class AppBase, defines the wrapper with basic attributes
• Class PythonApp, implements more attributes and the __call__() method to handle Python function.

The Future

• Inherited from Future in concurrent module

An AppFuture wraps a sequence of Futures which may fail and be retried.

The AppFuture will wait for the DFK to provide a result from an appropriate parent future, through parent_callback. It will set its result to the result of that parent future, if that parent future completes without an exception. This result setting should cause .result(), .exception() and done callbacks to fire as expected.

The DataFlowKernel

• DFK is the core mechanism! “The DataFlowKernel adds dependency awareness to an existing executor”
• app_fut is a result of dfk.submit()
• dfk.submit() takes all the arguments in the wrapper, i.e. the invocation_kwargs
• Class TaskRecord stores most information about a Parsl task.

executor Choices

• in submit of dfk, PythonApp.executors argument of the task is interpreted as choices
• DFK has its own slef.executors, which is a ThreadPoolExecutor by default.