如何从使用uWSGI异步执行的任务记录stderr

Question

In my Flask app I allocate a ThreadPool before the first request and use the threads allocated here to execute tasks asynchronously

from app import app
from multiprocessing.pool import ThreadPool


@app.before_first_request
def initialize():
    app.pool = ThreadPool(10)

Sometime later...

app.pool.apply_async(exporter, args=(domains))

I am using a uWSGI backend for my webserver and this works fine except my uwsgi log in /var/log/uwsgi/%n.log only logs the stdout from threads executed from this pool. I am unable to see the stderr . I was wondering if this was possible using uwsgi logging capabilities or if I have to use a pluggable logger. Thanks!

Answer 1

I reached a solution by just using the error_callback argument for apply_async .

I created a function:

def error_handler(e):
    traceback.print_exception(type(e), e, e.__traceback__)

And then execute the asynchronous task as follows:

app.pool.apply_async(exporter, args=(domains), error_callback=error_hander)

This returns the stderr to the main thread after it is done executing.