Google App Engine gunicorn worker timeout in Flask app when loading a large pickle?

Question

I have a 350 MB Sklearn pickle file that I want to load on Flask app start up.

I use _pickle because it's mentioned in documentation that it has faster load time:

import _pickle as pickle

start = timeit.default_timer()
with open("pickle/pipeline.pkl", 'rb') as f: 
        # ~350MB file
        pipeline = pickle.load(f)
        stop = timeit.default_timer()
        print('Time: ', stop - start)

The pickle loads in 5-12 seconds locally but on Google App Engine F4 (1GB RAM) instance, the gunicorn worker times out.

Google App Engine log:

A 2019-10-20T20:07:55Z [2019-10-20 20:07:55 +0000] [14] [INFO] Booting worker with pid: 14

A 2019-10-20T20:11:02Z [2019-10-20 20:04:14 +0000] [1] [CRITICAL] WORKER TIMEOUT (pid:14)

I tried increasing the worker timeout by adding the -t flag in app.yaml file as follows and still doesn't work:

runtime: python
instance_class: F4
env: flex
entrypoint: gunicorn -t 120 -b :$PORT app:app

liveness_check:
  initial_delay_sec: 500

readiness_check:
  app_start_timeout_sec: 500

I even tried using eventlet and it didn't work:

gunicorn -t 120 -b :$PORT app:app --worker-class eventlet --workers 3 

Answer 1

Try with entrypoint: gunicorn -t 0 -b :$PORT app:app it worked for me.

Answer 2

The process of loading a 350 MB pickle data file is taking too long and App Engine thinks your instance has failed. Your container startup time is over three minutes.

You have a problem that cannot be easily solved. The maximum file size is 32 MB (64 MB for Go applications). You are downloading the file to memory, but your instance is taking too long to download it.

Solution: I would use a different service such as Cloud Run where you can embed your pickle data file in the container image so that downloads are not required.