The suite definition describes the static structure, its not until the definition is loaded in the server, that we see its dynamic behaviour.
With ecflow python api, the dynamic behaviour of the suite can be simulated, ( i.e. in the same manner as the server).
Simulation has the following benefits:
The simulation relies on you adding simple verification attributes. (This is similar to c/c++/python asserts). These can be added on a task, family and suite nodes.(see below for an example)
There are however restrictions. If the definition has large loops due to, crons or Repeat attributes, which run indefinitely, then in this case the simulation will never complete, and will timeout after a years worth of run time.
This can be compensated for by adding start and end clock. If no start/end clock is specified, the simulator makes the following assumption about the simulation period.
Additionally if time base attributes like, time,today,cron have no minutes, then the simulator will use 1 hour resolution.
Here is an example of a text based suite definition that use a verify attribute, for which we want check our assumption about the dynamic behaviour.
suite year # use real clock otherwise the date wont change clock real 1.1.2017 # define a start date for deterministic simulation endclock 1.1.2018 # When to finish. A endclock is *ONLY* for use with the simulator. family cronFamily task t cron -d 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 -m 1,2,3,4,5,6,7,8,9,10,11,12 10:00 # run every day at 10am for a year verify complete:365 # verify that this task completes 365 times endfamily endsuite suite leap_year # use real clock otherwise the date wont change clock real 1.1.2016 # define a start date for deterministic simulation endclock 1.1.2017 # When to finish. A endclock is *ONLY* for use with the simulator. family cronFamily task t cron -d 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 -m 1,2,3,4,5,6,7,8,9,10,11,12 10:00 # run every day at 10am for a year verify complete:366 # verify that this task completes 366 times in a leap year endfamily endsuite |
This python segment shows how to load a text based suite definition(cron.def) and simulate it in python.
import ecflow defs = Defs("cron.def") result = defs.simulate() assert len(result) == 0, "Expected simulation to return without any errors, but found:\n" + result |
If the simulation does not complete it will produce two files, which will help in the analysis:
Both files will show which nodes are holding, and include the state of the holding trigger expressions.
This simulation is expected to fail, since we have a deadlock/ race condition
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