Lock Failure Not Reported

[rgstephens]

Description of Problem:
When hitting the REST endpoint with an utterance, we received no response. After that the REST endpoint stopped responding to requests. There were no messages related to the endpoint call - no indication that the user has sent an utterance. This made for difficult troubleshooting. Eventually figured out that there was an issue with a custom (clustered Redis) lock store.

Overview of the Solution:
The lock store code needs to add debug logging and report this type of error.

[wochinge]

more information in here: https://github.com/RasaHQ/rasa-x/issues/2079

[wochinge]

Debugging / Ideation

• in get_lock redis.get(...) blocks indefinitely
  • setting socket_timeout on the redis client helps

How to reproduce:

• run redis: docker run -p 6379:6379 redis
• use the following lock store config

lock_store:
    type: "redis"
    url: localhost
    port: 6379
    db: 0
    use_ssl: True. # using ssl if redis isn't configured so, will block. Set to `False` to make it working