Chapter 3. Enhancements
This section describes the major enhancements introduced in Red Hat OpenShift Data foundation 4.15.
3.1. Deployment of one active and one standby MGR pods by OCS Operator
The ocs-operator now deploys two MGR pods by default, one active and one standby. This enhancement does not impact cluster resource requirements.
3.2. Support for custom timeouts for Reclaim Space operation
Custom timeout values can be set for the reclaim space operation to avoid the failure of the operation with the error context deadline exceeded. The error would occur depending on the RBD volume size and its data pattern.
For more information, see Enabling reclaim space operation using ReclaimSpaceJob.
3.3. Modularized must-gather utility
OpenShift Data Foundation must-gather utility can be run in a modular mode and collect only the resources that are required. This enhancement helps to avoid long duration of time taken to run must-gather in some environments as well as focus on the inspected components faster.
For more information, see Downloading log files and diagnostic information using must-gather.
3.4. Prehook to MCG’s database pod to gracefully flush caches when the pod is going down
A prehook to Multicloud Object Gateway’s database pod (DB pod) is added to gracefully flush the cache when the pod is going down. This graceful shutdown reduces the risk of corruption in the journal file of the DB when the DB pod is taken down in a planned manner. However, this is not applicable for the shutdowns through OpenShift node crash or such.
3.5. All controller operations to reach one controller
When a CSI-driver provides the CONTROLLER_SERVICE capability, the sidecar tries to become the leader by obtaining a lease based on the name of the CSI-driver.
The Kubernetes CSI-Addons Operator tries to connect to the random CSI-Addons sidecar that is registered and try to make the RPC calls to the random sidecar. This can create a problem if the CSI-driver has implemented some internal locking mechanism or has some local cache for the lifetime of that instance.
The NetworkFence (and other CSI-Addons) operations are only sent to a CSI-Addons sidecar that has the CONTROLLER_SERVICE capability. There is a single leader for the CSI-Addons sidecars that support that, and the leader can be identified by the Lease object for the CSI-drivername.
3.6. Enhanced data distribution for CephFS storage class
This feature enables the default subvolume groups of Container Storage Interface (CSI) to be automatically pinned to the ranks according to the default pinning configuration. This is useful when you have multiple active CephFS metadata servers (MDSs) in the cluster. This helps to better distribute the load across MDS ranks in stable and predictable ways.
3.7. Ability to use bluestore-rdr as object storage device backing store
OpenShift Data Foundation provides the ability to use bluestore-rdr as the object storage device (OSD) backing store for the Brownfield customers. This bluestore-rdr has improved performance over bluestore backend store, which is important when the cluster is required to be used for Regional Disaster Recovery (RDR). Also, it is possible to migrate the OSDs to bluestore-rdr from the user interface.
