update_cluster

cloud.redu/mcp · Verify this server

Updates a running autoscaling cluster to a new app version IN PLACE, with NO URL change: snapshots the 'hero' VM (the source/master VM you SSH into and change — it is also the always-on baseline member that serves traffic), then redu rolling-updates the autoscaled extra members to that snapshot ONE AT A TIME and refreshes the image the group boots future members from — the SAME load balancer and SAME *.redu.cloud URL are kept, and the service stays up during the roll. This is the ONLY way to update a cluster: you do NOT edit live members (they are disposable clones); you change the hero VM (SSH into it, deploy the new version), then update_cluster snapshots it and spreads it to the fleet (the hero already runs your change; this propagates it to the autoscaled members). Zero-downtime is measured, not aspirational: a full roll of every member of a 3-member cluster served 699/699 requests with no failures and never dropped below a majority. That holds ONLY if the app starts on every boot - a member whose app is launched by a first-boot-only script returns empty after replacement, never rejoins the pool, and the roll silently drains the cluster. The snapshot upload can take several minutes on a large disk; poll list_clusters until the stack status is UPDATE_COMPLETE.