Description
Background:
The ExecutePythonProcessor is expected to have a limit on the maximal number of concurrent tasks it can run. This max_concurrent_tasks number is currently handled incorrectly, and the processor is able to run any number of tasks at the same time, but only max_concurrent_tasks script-engine is reused.
Proposal:
We should use max_concurrent_tasks as the size of script-engine pool for the processor and always use engines from this pool, wait otherwise.