High hardware costs see Red Hat offer a two-server edge rig, no mini-PC required

Summary

systems High hardware costs see Red Hat offer a two-server edge rig, no mini-PC required Worries about ‘prohibitive cost of powering, maintaining, and deploying a third node’ Red Hat has come up with a way to reduce the quantity of servers needed for high-availability edge deployments of its OpenShift platform, because its customers worry about high hardware costs.The IBM business unit’s Daniel Froehlich and Paul Lancaster last week introduced Red Hat’s approach in a post that saw the pair observe interest in “alternative topologies for large-scale edge deployments” due to “the prohibitive cost of powering, maintaining, and deploying a third node across hundreds or thousands of sites – a motivation that has only grown stronger in light of the recent steep increase in hardware prices.” That’s an interesting admission given that Red Hat already offers a way to run OpenShift with two nodes, by using an “arbiter” – a device with at least two virtual CPUs, 8GB of RAM, and 50GB of solid-state storage. The arbiter maintains quorum between the two nodes to help avoid the “split-brain problem” – a situation that occurs when a two-node cluster loses connectivity, and both servers assume they need to take over and act as the primary node. Each node will then run in parallel, possibly overwriting changes and making all sorts of mess. To stop that happening, the arbiter steps in and effectively appoints one node as cluster boss. Now it seems that even the cost of an arbiter, and the added complexity of running even such a modest machine, has become an issue.Big Blue’s FOSS house therefore adapted some tech from its Red Hat Enterprise Linux High Availability Add-On, namely Corosync and Pacemaker, to adopt a technique called fencing.Froehlich and Lancaster explain that fencing matters because it can avoid split-brain problems.“Fencing imposes consistency by requiring that Pacemaker on the surviving node forcefully powers down or reboots the failed or disconnected node,” they wrote...