Service chaining is a Contrail feature that deploys
a VM-Series firewall as a service instance in your OpenStack environment.
A service chain is a set of service virtual machines, such as firewalls
or load balancers, and each virtual machine in the service chain
is a service instance. Service scaling allows you to dynamically deploy
additional instances of the VM-Series firewall. Using CPU utilization
or incoming bytes per second metrics gathered by Ceilometer, OpenStack
deploys or shuts down additional instances of the VM-Series firewall
to meet the current needs of your network.
The VM-Series firewall in OpenStack solution leverages heat orchestration
templates to configure and deploy the components required for service
chaining and service scaling. The heat templates provided by Palo
Alto networks create a service template, service instance, and service
policy (to direct traffic to the VM-Series firewall) to deploy two
Linux servers and the VM-Series firewall service instance between