Bug 1814605
| Summary: | [OSP] Minimal compute node requirements are too small to stand up a cluster | ||
|---|---|---|---|
| Product: | OpenShift Container Platform | Reporter: | Martin André <m.andre> |
| Component: | Installer | Assignee: | Pierre Prinetti <pprinett> |
| Installer sub component: | OpenShift on OpenStack | QA Contact: | David Sanz <dsanzmor> |
| Status: | CLOSED ERRATA | Docs Contact: | |
| Severity: | medium | ||
| Priority: | high | CC: | mbridges, mschuppe, pprinett |
| Version: | 4.4 | ||
| Target Milestone: | --- | ||
| Target Release: | 4.5.0 | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: |
Documentation change. Clearly state that 3 workers are needed for the cluster to be functional.
|
Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | 2020-07-13 17:22:24 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
As of 4.5, I was able to deploy a cluster with 3 master nodes and 3 worker nodes, with the minimum required resources described in the docs. However, a cluster with only 2 workers was not healthy and had multiple failed pods. The proposed change removes reference to healthy clusters with 2 workers only. Verified Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2020:2409 |
We currently document a minimum of 2 vCPUs, 8 GB RAM and 25 GB Disk for the compute nodes. CPU, at least, is not enough to stand up a cluster. ERROR Cluster operator monitoring Degraded is True with UpdatingPrometheusK8SFailed: Failed to rollout the stack. Error: running task Updating Prometheus-k8s failed: waiting for Prometheus object changes failed: w aiting for Prometheus: expected 2 replicas, updated 1 and available 1 FATAL failed to initialize the cluster: Cluster operator monitoring is still updating ❯ oc get pods -A | grep -v Running | grep -v Completed NAMESPACE NAME READY STATUS RESTARTS AGE openshift-monitoring prometheus-k8s-1 0/7 Pending 0 12m ❯ oc describe pod -n openshift-monitoring prometheus-k8s-1 | tail QoS Class: Burstable Node-Selectors: kubernetes.io/os=linux Tolerations: node.kubernetes.io/memory-pressure:NoSchedule node.kubernetes.io/not-ready:NoExecute for 300s node.kubernetes.io/unreachable:NoExecute for 300s Events: Type Reason Age From Message ---- ------ ---- ---- ------- Warning FailedScheduling <unknown> default-scheduler 0/6 nodes are available: 3 Insufficient cpu, 3 node(s) had taints that the pod didn't tolerate. Warning FailedScheduling <unknown> default-scheduler 0/6 nodes are available: 3 Insufficient cpu, 3 node(s) had taints that the pod didn't tolerate. ❯ oc describe node mandre-vex-pdldk-worker-d5nws | tail -n 7 Resource Requests Limits -------- -------- ------ cpu 1432m (95%) 100m (6%) memory 3331Mi (48%) 537Mi (7%) ephemeral-storage 0 (0%) 0 (0%) attachable-volumes-cinder 0 0 ❯ openstack flavor show v1-standard-2 +----------------------------+--------------------------------------+ | Field | Value | +----------------------------+--------------------------------------+ | OS-FLV-DISABLED:disabled | False | | OS-FLV-EXT-DATA:ephemeral | 0 | | access_project_ids | None | | disk | 100 | | id | d68a5cb5-f133-460d-bc5b-81fd140325c9 | | name | v1-standard-2 | | os-flavor-access:is_public | True | | properties | | | ram | 8192 | | rxtx_factor | 1.0 | | swap | | | vcpus | 2 | +----------------------------+--------------------------------------+