All OpenStack projects have an API service for controlling all the resources in the Cloud. In Active / Active mode, the most common setup is to scale-out these services on at least two nodes and use load-balancing and virtual IP (with HAproxy & Keepalived in this setup).
Configuring API OpenStack services
To configure our Cloud using Highly available and scalable API services, we need to ensure that:
- Using Virtual IP when configuring OpenStack Identity Endpoints.
- All OpenStack configuration files should refer to Virtual IP.
In case of failure
The monitor check is quite simple since it just establishes a TCP connection to the API port. Comparing to the Active / Passive mode using Corosync & Resources Agents, we don’t check if the service is actually running). That’s why all OpenStack API should be monitored by another tool (i.e. Nagios) with the goal to detect failures in the Cloud Framework infrastructure.
