"Unable to connect to AMQP server" Displayed When Running Heat

Symptom

The Heat component cannot connect to the RabbitMQ server when Heat is running, and the connections between other components and the RabbitMQ server are also affected. "Unable to connect to AMQP server" is displayed.

Key Process and Cause Analysis

When the default settings are used, excessive Heat processes are beyond the processing scope of the AMQP server.

Conclusion and Solution

Modify the RabbitMQ server and Heat settings.

1. Open the /etc/rabbitmq/rabbitmq.config file.

   vim /etc/rabbitmq/rabbitmq.config

   Modify delegate_count as follows:

   {delegate_count, 96}

2. Open the /etc/heat/heat.conf file.

   vim /etc/heat/heat.conf

   Add the following configurations:

   [heat_api]
   workers = 4
   [DEFAULT]
   num_engine_workers = 4

3. Restart the Heat service.

   systemctl restart openstack-heat-api.service openstack-heat-api-cfn.service openstack-heat-engine.service