Chapter 4. Technology previews
This section describes the technology preview features introduced in Red Hat OpenShift Data Foundation 4.15 under Technology Preview support limitations.
Technology Preview features are not supported with Red Hat production service level agreements (SLAs), might not be functionally complete, and Red Hat does not recommend using them for production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.
Technology Preview features are provided with a limited support scope, as detailed on the Customer Portal: Technology Preview Features Support Scope.
4.1. Multicloud Object Gateway to use external PostgreSQL
Multicloud Object Gateway (MCG) is allowed to use an external PostgreSQL to get a high availability solution where the PostgreSQL pod is a single point of failure. This solution provides a way to use external PostgreSQL independent of OpenShift Data Foundation.
For more information, see the deployment guide for your platform in the OpenShift Data Foundation documentation.
4.2. Disaster Recovery for brownfield deployments
With this release, disaster recovery can be enabled for an existing cluster which was deployed using OpenShift Data Foundation 4.13 or earlier or using OpenShift Data Foundation 4.14 without the Disaster Recovery flag enabled.
For more information, see the knowledgebase article, OpenShift Data Foundation cluster migration: Optimizing the cluster for Regional-DR.
4.3. Enable monitoring support for ACM Subscription application type
The disaster recovery dashboard on Red Hat Advanced Cluster Management (RHACM) console is extended to display monitoring data for Subscription type applications in addition to ApplicationSet type applications.
Data such as the following can be monitored:
- Volume replication delays
- Count of protected Subscription type applications with or without replication issues,
- Number of persistent volumes with replication healthy and unhealthy
Application-wise data like the following:
- Recovery Point Objective (RPO)
- Last sync time
- Current DR activity status (Relocating, Failing over, Deployed, Relocated, Failed Over),
- Application-wise persistent volume count with replication healthy and unhealthy.
4.4. Support ReadWriteOncePod access mode
OpenShift Data Foundation introduces the new ReadWriteOncePod (RWOP) access mode. With this RWOP access mode, it can be ensured that only one pod across the whole cluster can read that PVC or write to it. This access mode can be used either from the YAML file or the command-line interface only.
4.5. Support for efficient SELinux volume relabeling
OpenShift Data Foundation has introduced an efficient SELinux relabeling for ReadWriteOncePod access mode. This helps to reduce the time consumption when the volume is mounted on a remote filesystem such as CephFS and when there are many files on the volume. This operation is faster than labeling all the files and folders individually.
4.6. Hub recovery support for co-situated and neutral site deployments
The Metropolitan and Regional disaster recovery solutions of OpenShift Data Foundation now support neutral site deployments and hub recovery of co-situated managed clusters using Red Hat Advanced Cluster Management. For configuring hub recovery setup, a 4th cluster is required which acts as the passive hub.
The passive hub cluster can be set up in either one of the following ways:
- The primary managed cluster (Site-1) can be co-situated with the active RHACM hub cluster while the passive hub cluster is situated along with the secondary managed cluster (Site-2).
- The active RHACM hub cluster can be placed in a neutral site (Site-3) that is not impacted by the failures of either of the primary managed cluster at Site-1 or the secondary cluster at Site-2. In this situation, if a passive hub cluster is used it can be placed with the secondary cluster at Site-2.
For more information, see respective Metro-DR and Regional-DR chapters on Hub recovery using Red Hat Advanced Cluster Management.
