How to find out what's stuck in your queues in Redis
Start redis-cli that should have come with your redis distribution. Start redis-cli and type "keys *" (without the quotes) and hit return. That will show you what keys (queues) have data in them. See this stackoverflow discussion:
you can explore the Redis dataset using the 'redis-cli' tool included in the Redis distribution. Just start the tool without arguments, then type commands to explore the dataset. For instance KEYS will list all the keys matching a glob-style pattern, for instance with: keys * you'll see all the keys available.
Read more: ruby - Dumping all key/value pairs in a Redis db - Stack Overflow