Cause: The RPC response timeout for communication between the heat-api and heat-engine processes is supposed to be increased from the default value in a director undercloud. However, due to https://bugzilla.redhat.com/show_bug.cgi?id=1305947 this configuration change is missing on underclouds originally installed with director 7.2.
Consequence: Heat stack operations on the undercloud may fail with a MessagingTimeout error.
Workaround (if any): In the file /etc/heat/heat.conf on the undercloud, change the line:
(i.e. remove the initial # to uncomment it, and change the value from 60 to 600.)
Then restart the heat services:
systemctl restart openstack-heat-api.service
systemctl restart openstack-heat-api-cfn.service
systemctl restart openstack-heat-engine.service
Result: Heat will be running using the correct timeouts.