After three years of using BOSH I'm still surprised that bosh cancel task is relatively ineffective. It doesn't immediately cancel the task; rather it registers the request, and patiently waits for the current task to get into a state where you could safely cancel it. Which is almost never what you want. You know something is wrong and you want to cancel the task NOW.

More importantly perhaps: you want to unlock the current deployment.

BOSH has a lock over each deployment - you can only perform one deployment per deployment name at a time. So if you cannot cancel a task that has locked a deployment, then you cannot perform a subsequent task.

The rest of this article documents how to find and delete a lock.

Where is a BOSH lock?

BOSH uses Redis for locks. To find the location and password for Redis, look in the Director's configuration:

$ cat /var/vcap/jobs/director/config/director.yml | grep redis -A3
  port: 25255
  password: redis
    level: info

For a single VM BOSH, Redis will be running on the same host on port 25255.

To connected to Redis, add the redis-cli to the $PATH:

export PATH=$PATH:/var/vcap/packages/redis/bin  
redis-cli -p 25255 -a redis  

To find the lock, look up all current locks:

> keys "lock:*"
1) "lock:deployment:my-locked-deployment"  

There it is - the "deployment" lock for deployment "my-locked-deployment".

Delete it with Redis command del:

> del lock:deployment:my-locked-deployment
(integer) 1