Failed to Restart openstack-nova-compute.service

Symptom

openstack-nova-compute.service fails to be restarted.

Key Process and Cause Analysis

Check the log /var/log/nova/nova-compute.log.

vi /var/log/nova/nova-compute.log

Unhandled error: amqp.exceptions.AccessRefused: (0, 0): (403) ACCESS_REFUSED - Login was refused using authentication mechanism AMQPLAIN. For details see the broker logfile.

According to the log, the root cause is that Nova fails to be connected to RabbitMQ.

Conclusion and Solution

1. Check whether the RabbitMQ-related configurations in Nova are correct.

   transport_url = rabbit://openstack:RABBIT_PASS@controller:5672/

   

   Replace RABBIT_PASS with the OpenStack user password.

2. Check whether the OpenStack user exists in RabbitMQ.

   rabbitmqctl list_users

   Figure 1 RabbitMQ users
   

   In some cases, RabbitMQ data is lost causing OpenStack user loss. If the OpenStack user is lost, add the OpenStack user again.

   rabbitmqctl add_user openstack RABBIT_PASS

   Set the permission of the OpenStack user so that the user can perform configuration, write, and read operations.

   rabbitmqctl set_permissions openstack ".*" ".*" ".*"