High Availability and Clusters

The following features for high availability and clusters are available as technology previews.

Pacemaker Podman Bundles

Pacemaker container bundles now run on Podman, with the container bundle feature being available as a Technology Preview.

Heuristics in corosync-qdevice

Heuristics are a set of commands that run locally on startup, cluster membership change, successful connect to corosync-qnetd, and, optionally, on a periodic basis. When all commands finish successfully, heuristics have passed; otherwise, they have failed. The heuristics result is sent to corosync-qnetd where it's used in calculations to decide which partition is quorate.

Fence Agent

The fence_heuristics_ping agent is available with Pacemaker. The agent aims to open a class of experimental fence agents that do no actual fencing by themselves but instead exploit the behavior of fencing levels in a new way.

Through the agent, particularly by its issuing an off action, Pacemaker can be informed if fencing would succeed or not. The heuristics agent can prevent the agent that does the actual fecing from fencing a node under certain conditions.