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The ecFlow user interface (ecFlowview) uses the same technology and user paradigm as XCDP. The graphical user interface (GUI) is X-Windows based. This places limits on the machines where user interface can be run, since the X windows libraries will require a separate installation. This will be replaced in the near future, with a more intuitive and up to date GUI.
When ecFlow is released the online documentation and tutorial can be accessed from: http://www.ecmwf.int/publications/manuals/ecflow/
We welcome feedback on any aspect of ecFlow. Suggestions for further developments will be assessed and, where appropriate, they will be prioritised and fed into future versions.
Box A. Correct by constructionThe following examples show usage of the new Python API. The API supports a correct by construction approach. For example, adding tasks of the same name at the same level will throw a RuntimeError exception:
Example 1
import ecflow defs = ecflow.Defs() suite = defs.add_suite("s1") suite.add_task("t1") suite.add_task("t1") # RuntimeError exception thrown
>> RuntimeError: Add Task failed: A task of name 't1' already exist on node SUITE:/s1
Example 2
Adding dependencies, such as dates, are also checked:
import ecflow defs = ecflow.Defs() suite = defs.add_suite("s1") task t1 = suite.add_task("t1") t1.add_date(1,14,2007) # day,month,year, month is not valid
>> IndexError: Invalid Date(day,month,year): the month >=0 and month <= 12, where 0 means wild card |
Box B. CheckingExpression checkingSome checking has to be deferred until the definition is fully defined. Here is a simple example showing the checking of trigger expressions: | Code Block |
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| import ecflow
defs = ecflow.Defs()
suite = defs.add_suite("s1");
suite.add_task("t2")
suite.add_task("t1").add_trigger("t2 == active)")
assert len(defs.check()) != 0, "Expected Error: miss-matched brackets in expression." |
Job checkingJob creation is the process of locating an '.ecf' script corresponding to a task and then generating a job file. This can be checked before a definition is loaded into the server using the Python API. | Code Block |
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| # Generate jobs for the ALL tasks in the definition given by variable 'defs'
# and print errors to standard out.
import ecflow
defs = ecflow.Defs()
suite = defs.add_suite("s1");
suite.add_task("t1") |
job
ob_ctrl = JobCreationCtrl()
defs.check_job_creation( job_ctrl )
print job_ctrl.get_error_msg() |
Job control provides additional functionality to control which nodes are generated and control over the directory used for job generation.
Dead lock checkingSimulation allows a suite definition to be checked without the need for scripts or a server. By default the simulation will run for a year before quitting. This can take a couple a seconds to a few minutes depending on the complexity of the suite definition. However, it is most useful where we have a definition which is known to complete. Here is an example which will cause a deadlock that is detectable by the simulator.
import os from ecflow import *
defs = Defs() suite = defs.add_suite("dead_lock") fam = suite.add_family("family") fam.add_task("t1").add_trigger("t2 == complete") fam.add_task("t2").add_trigger("t1 == complete")
theResult = defs.simulate(); assert len(theResult) != 0, "Expected simulation to return errors, but found none" print theResult
os.remove("defs.depth") # provides reason why simulation could not complete os.remove("defs.flat") # provides reason why simulation could not complete
Early checking of the suite definition will help to speed up the development of suites. |
Box C. Boost C++ libraries used in ecFlow- Boost-ASIO library is used to provide the core of the client-server implementation. It also provides a deadline timer for polling and support for time outs.
- Boost-Python library enables seamless interoperability between C++ and the Python programming language.
- Boost-Program options are used to parse the client and server program options, and they provide the corresponding help strings.
- Boost-Spirit provides the parsing for expressions. The abstract syntax tree is then created from the spirit nodes.
- Boost-Test library is used for unit and regression tests of the C++ and Python code.
- Boost-Date-Time library is used in the suite calendar, time based attributes and polling.
- Boost-File System library is used for file queries in a platform independent manner.
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