Error on bench restart -

Any idea what this error is about? I get this when I restart the bench

File “/home/kirthi/frappe-bench/env/local/lib/python2.7/site-packages/redis/connection.py”, line 436, in connect
raise ConnectionError(self._error_message(e))
ConnectionError: Error 111 connecting to localhost:6379. Connection refused.
[2015-10-15 18:06:28,663: ERROR/MainProcess] consumer: Cannot connect to redis://localhost:6379//: Error 111 connecting to localhost:6379. Connection refused…
Trying again in 2.00 seconds…

worker: Cold shutdown (MainProcess)
[2015-10-15 18:09:07,587: WARNING/MainProcess] celery@erpnext ready.
[2015-10-15 18:16:01,706: WARNING/MainProcess] consumer: Connection to broker lost. Trying to re-establish the connection…
Traceback (most recent call last):
File “/home/kirthi/frappe-bench/env/local/lib/python2.7/site-packages/celery/worker/consumer.py”, line 278, in start
blueprint.start(self)
File “/home/kirthi/frappe-bench/env/local/lib/python2.7/site-packages/celery/bootsteps.py”, line 123, in start
step.start(parent)
File “/home/kirthi/frappe-bench/env/local/lib/python2.7/site-packages/celery/worker/consumer.py”, line 821, in start
c.loop(*c.loop_args())
File “/home/kirthi/frappe-bench/env/local/lib/python2.7/site-packages/celery/worker/loops.py”, line 70, in asynloop
next(loop)
File “/home/kirthi/frappe-bench/env/local/lib/python2.7/site-packages/kombu/async/hub.py”, line 267, in create_loop
tick_callback()
File “/home/kirthi/frappe-bench/env/local/lib/python2.7/site-packages/kombu/transport/redis.py”, line 943, in on_poll_start
cycle_poll_start()
File “/home/kirthi/frappe-bench/env/local/lib/python2.7/site-packages/kombu/transport/redis.py”, line 300, in on_poll_start
self._register_BRPOP(channel)
File “/home/kirthi/frappe-bench/env/local/lib/python2.7/site-packages/kombu/transport/redis.py”, line 283, in _register_BRPOP
self._register(*ident)
File “/home/kirthi/frappe-bench/env/local/lib/python2.7/site-packages/kombu/transport/redis.py”, line 268, in _register
client.connection.connect()
File “/home/kirthi/frappe-bench/env/local/lib/python2.7/site-packages/redis/connection.py”, line 436, in connect
raise ConnectionError(self._error_message(e))
ConnectionError: Error 111 connecting to localhost:6379. Connection refused.
[2015-10-15 18:16:01,712: ERROR/MainProcess] consumer: Cannot connect to redis://localhost:6379//: Error 111 connecting to localhost:6379. Connection refused…
Trying again in 2.00 seconds…

worker: Cold shutdown (MainProcess)
[2015-10-15 18:23:17,259: WARNING/MainProcess] celery@erpnext ready.

Seems port 6379 is busy with another process, kill process and then start bench again.