Using the Jaeger Python client together with Luigi

Question

I'm just starting to use Jaeger for tracing and want to get the Python client to work with Luigi. The root of the problem is, that Luigi uses multiprocessing to fork worker processes. The docs mention that this can cause problems and recommend - in case of web apps - to defer the tracer initialization until the request handling process has been forked. This does not work for me, because I want to create traces in the main process and in the worker processes.

In the main process I initialize the tracer like described here:

from jaeger_client import Config
config = Config(...)
tracer = config.initialize_tracer()

This creates internally a Tornado io-loop that cannot be reused in the forked processes. So I try to re-initialize the Jaeger client in each Luigi worker process. This is possible by setting the (undocumented?) task_process_context of the worker-Section to a class implementing the context manager protocol. It looks like this:

class WorkerContext:
    def __init__(self, process):
        pass

    def __enter__(self):
        Config._initialized = False
        Config._initialized_lock = threading.Lock()

        config = Config(...)
        self.tracer = config.initialize_tracer()

    def __exit__(self, type, value, traceback):
        self.tracer.close()
        time.sleep(2)

Those two lines are of course very "hackish":

Config._initialized = False
Config._initialized_lock = threading.Lock()

The class variables are copied to the forked process and initialize_tracer would complain about already being initialized, if I would not reset the variables.

The details of how multiprocessing forks the new process and what this means for the Tornado loop are somewhat "mystic" to me. So my question is:

Is the above code safe or am I asking for trouble?

Of course I would get rid of accessing Configs internals. But if the solution could be considered safe, I would ask the maintainers for a reset method, that can be called in a forked process.