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Change Summary v1.12

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Kiran Mova edited this page Jul 15, 2020 · 5 revisions

Status: Released on 15-July-2020

Important Announcement: OpenEBS Community Slack channels are migrated to Kubernetes Slack Workspace

In the interest of neutral governance, the OpenEBS community support via slack has moved from openebs-community slack (a free version of slack with limited support for message retention) to the following OpenEBS channels on Kubernetes Slack owned by CNCF.

Given that openebs-community slack has been a neutral home for many vendors that are offering free and commercial support/products on top of OpenEBS, the workspace will continue to live on. These vendors are requested to create their own public channels and the information about those channels can be communicated to users via the OpenEBS website by raising an issue/pr to https://github.com/openebs/website.

Table of contents

Security Vulnerabilities Fixed

None

Deprecated Releases or Features

Releases prior to 1.0 have been deprecated. The steps to upgrade are here.

The minimum recommended velero version to be used with OpenEBS is 1.4.0 or higher.

Breaking Changes

  • Important Note for OpenEBS Helm Users: The repository https://github.com/helm/charts is being deprecated. All the charts are now being moved to Helm Hub or to project-specific repositories. OpenEBS charts have migrated to openebs/charts repository. Starting with 1.12.0, openebs can be installed via the following helm commands:

    helm repo add openebs https://openebs.github.io/charts
helm repo update
helm install --namespace openebs --name openebs openebs/openebs

  • Important Note on Jiva Volume upgrade: If you are upgrading Jiva volumes from version 1.6 and 1.7. You must use these pre-upgrade steps to check if your jiva volumes are impacted by openebs/openebs#2956. If they are, please reach out to us on Slack or create an GitHub issue for helping you with the upgrade.

New Capabilities

This was mainly a maintenance release enhancing the existing capabilities and improving the CI/CD aspects for various components.

Alpha Feature Updates

  • [Mayastor] Active development is underway on OpenEBS Mayastor developed using NVMe based architecture, targetted at addressing performance requirements of IO-intensive workloads is ready for alpha testing. For detailed instructions on how to get started with Mayastor please refer to this Quickstart guide. Mayastor is currently at version 0.2.0. To learn about the design choices and internals of Mayastor, please refer to this Webinar from the authors of Mayastor. In the current release, work has largely been in the areas of research, refactoring and enhancing CI/CD/Test capability.

  • [cStor CSI and Enhanced Operators] Active development is underway to provide CSI support for cStor. For current status and detailed instructions on how to get started with provisioning cStor with CSI Driver and Enhanced Operators, please refer to the Quick start guide. This project made the following updates since its last release:

    • Added missing features like setting podAffinity, Luworkers for cStor Target Deployment, configuring zvol workers on cStor volume Replicas.
    • Enhanced the status reporting of CSPC to display provisioned and healthy replica count
    • Enhance the Upgrade of CSPC and Migration of SPC to CSPC based on additional integration tests. As part of migration automatically create the CVP from SC CAS Config annotations.
    • Add additional validations for Scale-up/down operations on CSPC pools.
    • Add additional integration and unit tests.

  • [NDM] Continuing to make progress on the NDM feature added in OpenEBS v1.10.0 to help with discovering partitions and virtual drives that don't have any uniquely identifiable attributes like a serial number or wwn. openebs/node-disk-manager#386. This feature makes use of the partition/filesystem id if it exists or will create a partition on an empty block device and use that partition id for unique identification. This feature is not yet ready for production use cases and can be enabled via a feature gate flag. The feature gate can be enabled by:

    • adding an additional arg (--feature-gates=GPTBasedUUID) to NDM DaemonSet, in case of Operator/YAML based install or
    • via Helm flags featureGates.enabled=true and featureGates.GPTBasedUUID.featureGateFlag=GPTBasedUUID.

    In the current release, we continued working on supporting the migration of older Block Devices to make use of the new UUID feature.

  • [Support for ARM images] In this release added support for Multi-arch images for NDM components. Thanks to @xUnholy. We are in the process of adding the multi-arch support to other repositories in the upcoming release. We have a lot of new users trying out the ARM images, providing feedback, and helping with adding new features. We need more support/help with running tests on different flavors of ARM. If you would like to help out, please join us on Slack. You can use this YAML to install Dynamic Local PV provisioner for your ARM64 nodes.

  • [Support for PowerPC images] We have NDM, Local PV Provisioner images ready to be tested. If you are interested in helping us take this forward, please join our active contributor and user community on Slack. You can use this YAML to install Dynamic Local PV provisioner for your power nodes.

  • [RawFile - Local PV] We are working on a new type of Dynamic Local PV called RawFile - Local PV, backed by a single file on host filesystem as the block device, using Linux’s loop. This is aimed at addressing some of the concerns around quota management and metrics with hostpath Local PVs. To learn more about this new PV and to help us develop this feature, please reach out to OpenEBS Contributor Community.

Enhancements

  • [Build] Refactor and add multi-arch image generation support on the NDM repo. node-disk-manager#428 (@xUnholy)
  • [Install] Support specifying the webhook validation policy to fail/ignore via ENV (ADMISSION_WEBHOOK_FAILURE_POLICY) on admission server deployment. maya#1726 (@prateekpandey14)
  • [NDM] Enhanced NDM Operator to attach events to BDC CR while processing BDC operations. node-disk-manager#425 (@rahulchheda)
  • [ZFS Local PV] Add support for btrfs as an additional FS Type. zfs-localpv#170 (@pawanpraka1, @mikroskeem)
  • [ZFS Local PV] Add support for shared mount. zfs-localpv#164 (@pawanpraka1, @stevefan1999-personal)
  • [ZFS Local PV] Refactored the code to make use of klog, added additional BDD tests. (@pawanpraka1, @vaniisgh)

Major Bug Fixes

  • [NDM] Fixes an issue where NDM would not wipe the filesystem of the released block device if the consumer partitioned the block device. node-disk-manager#445 (@akhilerm)
  • [NDM] Fixes an issue where NDM failed to close an fd open to a block device causing the cStor volume to wait for 30 min to for the fd to be released.node-disk-manager#450 (@akhilerm)
  • [Provisioners] Fixes a panic on maya-apiserver caused due to PVC names longer than 63 chars. maya#1720 (@kmova @stuartpb)
  • [Upgrade] Fixes an issue where the upgrade was failing some pre-flight checks when the maya-apiserver was deployed in HA mode. maya#1720 (@shubham14bajpai @utkudarilmaz)
  • [Upgrade] Fixes an issue where the upgrade was failing if the deployment rollout was taking longer than 5 min. maya#1719 (@shubham14bajpai @sgielen)

E2E Testing Updates

  • [New Test - Backup/Restore] Validate Backup/Restore on cStor Volumes provisioned via CSI driver. e2e-tests#416 (@shashank855)
  • [New Test - ZFS Local PV] Validate support for btrfs filesystem. e2e-tests#437 (@w3aman)
  • [New Test - cStor CSPC/CSI] Validate upgrade of cStor Pools and Volumes using the new schema. e2e-tests#421 (@nsathyaseelan)
  • [New Test - cStor CSPC/CSI] Validate migration of cStor Pools and Volumes from old to new schema. e2e-tests#434 (@nsathyaseelan)
  • [Enhance Test - cStor CSPC/CSI] Validate cStor operations by introducing network delay in cstor csi target pods. e2e-tests#427 (@nsathyaseelan)
  • [Enhance Test - Backup/Restore] Upgrade the automation pipeline to use Velero 1.4.0. e2e-tests#403 (@shashank855)
  • [Enhance Test - ZFS Local PV] Validate that scaling down the application prior to creating snapshot will take app consistent snapshot. e2e-tests#440 e2e-tests#445(@w3aman)
  • [Manual Test - ZFS Local PV] Validate on CentOS-based cluster.
  • [Manual Test - ZFS Local PV] Validate using ZFS Local PV with a shared mount option.

E2E Platform Updates

Automated end-to-end tests are executed using the GitLab runner. The following platforms were verified.

  • Kubernetes 1.15.2, 1.16.1, 1.17.2
  • OpenShift 4.2
  • Konvoy V1.2.3

Backward Incompatibilities

This release removes the support for managing volumes that are in OpenEBS 0.9.x version or earlier. Please upgrade your volumes in versions 0.9.0 or earlier to 1.0, before upgrading to this release

For releases prior to 1.0, please refer to the respective release notes and upgrade steps.

  • From 1.0.0: None.

  • From 1.2: If the status of CSP is either in Init or PoolCreationFailed, then cstor-pool-mgmt container in pool pod will attempt to create the pool. So, when there is a need to re-create pool for the same CSP due to ephemeral storage, CSP CR related to this pool needs to be edited to set status.phase as Init. As part of reconciliation, cstor-pool-mgmt container of pool pod will attempt to recreate the pool. Refer openebs/maya#1401 for more details.

  • From 1.3.0: None

  • From 1.4.0: None

  • From 1.5.0: Dumping cores have been disabled by default for cStor pool and NDM DaemonSet pods. This can be enabled by setting an ENV variable ENABLE_COREDUMP to 1. The ENV setting can be added in cStor pool deployment for dumping core for cStor pool pod and the ENV setting can be added in NDM DaemonSet spec for dumping core for NDM DaemonSet pods.

  • From 1.6.0, 1.7.0: OpenEBS v1.8 includes a critical fix (#2956) for Jiva volumes that are running in version 1.6 and 1.7. You must use these pre-upgrade steps to check if your jiva volumes are impacted. If they are, please reach out to us on OpenEBS Community for helping you with the upgrade.

  • From 1.8.0, 1.9.0, 1.10.0: None

  • From 1.11.0: If you have installed openebs using helm stable/openebs repository, please change to openebs/openebs repo.

Important Notes: If you are on OpenEBS v1.8 or an earlier release, please be aware of the following changes when upgrading to 1.10.

  • The way Jiva volume-related Kubernetes objects (Jiva Target and Controller Deployment, Jiva Target Service) are deployed. These changes are required to tighten RBAC policies for OpenEBS Service Account and to better support Jiva volumes in production. For more details refer to the Jiva Data Engine Enhancements.

  • OpenEBS Velero plugin container image tag format has changed to specify only OpenEBS release version. For instance:

    • OpenEBS Velero plugin v1.10 will be available at openebs/velero-plugin:1.10.0
    • OpenEBS Velero plugin earlier versions like v1.8 included the minimum velero version required like openebs/velero-plugin:1.8.0-velero_1.0.0.

Also, as part of OpenEBS upgrade or installation, maya-apiserver pod will restart if NDM BlockDevice CRDs are not created before the creation of maya-apiserver. https://github.com/openebs/maya/pull/1381

Install

Prerequisite to install

  • Kubernetes 1.14+ is installed. If using Kubernetes 1.16+ then please use OpenEBS 1.8 and above.
  • Make sure that you run the below installation steps with the cluster-admin context. The installation will involve creating a new Service Account and assigning it to OpenEBS components.
  • Make sure that iSCSI Initiator is installed on all the Kubernetes nodes.
  • Node-Disk-Manager (NDM) helps in discovering the devices attached to Kubernetes nodes, which can be used to create storage pools. If you like to exclude some of the disks from getting discovered, update the filters in NDM Config Map to exclude paths before installing OpenEBS.
  • NDM runs as a privileged pod since it needs to access the device information. Please make the necessary changes to grant access to run in privileged mode. For example, when running in RHEL/CentOS, you may need to set the security context appropriately. Refer Configuring OpenEBS with selinux=on

Install using kubectl

kubectl apply -f https://openebs.github.io/charts/1.12.0/openebs-operator.yaml

Install using helm stable charts

helm repo update
helm install --namespace openebs --name openebs openebs/openebs --version 1.12.0

For more details refer to the documentation at https://docs.openebs.io/

Upgrade

The steps to upgrade are here. Kubernetes Job-based upgrades to version 1.12 are supported only from 1.0 or higher and follow a similar process as earlier releases.

  • Upgrade OpenEBS Control Plane components.
  • Upgrade Jiva PVs to 1.12, either one at a time or multiple volumes. Note that it is recommended to scale down the applications using Jiva volumes prior to upgrading.
  • Upgrade CStor Pools to 1.12 and its associated Volumes, one at a time or multiple volumes.

For upgrading from releases prior to 1.0, please refer to the respective release upgrade here.

Uninstall

The recommended steps to uninstall are:

  • delete all the OpenEBS PVCs that were created
  • delete all the SPCs (in case of cStor)
  • ensure that no volume or pool pods are pending in terminating state kubectl get pods -n <openebs namespace>
  • ensure that no openebs cStor volume custom resources are present kubectl get cvr -n <openebs namespace>
  • delete all openebs related StorageClasses.
  • delete the openebs either via helm purge or kubectl delete

Uninstalling OpenEBS doesn't automatically delete the CRDs that were created. If you would like to remove CRDs and the associated objects completely, run the following commands:

```
kubectl delete crd castemplates.openebs.io
kubectl delete crd cstorpools.openebs.io
kubectl delete crd cstorvolumereplicas.openebs.io
kubectl delete crd cstorvolumes.openebs.io
kubectl delete crd runtasks.openebs.io
kubectl delete crd upgradetasks.openebs.io
kubectl delete crd storagepoolclaims.openebs.io
kubectl delete crd storagepools.openebs.io
kubectl delete crd volumesnapshotdatas.volumesnapshot.external-storage.k8s.io
kubectl delete crd volumesnapshots.volumesnapshot.external-storage.k8s.io
kubectl delete crd disks.openebs.io
kubectl delete crd blockdevices.openebs.io
kubectl delete crd blockdeviceclaims.openebs.io
kubectl delete crd cstorbackups.openebs.io
kubectl delete crd cstorrestores.openebs.io
kubectl delete crd cstorcompletedbackups.openebs.io
kubectl delete crd cstorvolumeclaims.openebs.io
kubectl delete crd cstorpoolclusters.openebs.io
kubectl delete crd cstorpoolinstances.openebs.io
```

Note: As part of deleting the Jiva Volumes - OpenEBS launches scrub jobs for clearing data from the nodes. The completed jobs need to be cleared using the following command: kubectl delete jobs -l openebs.io/cas-type=jiva -n <namespace>

Limitations / Known Issues

For a more comprehensive list of open issues uncovered through e2e and community testing, please refer to GitHub open issues. Here is a quick summary of common known issues.

  • The current version of OpenEBS cStor is not optimized for performance-sensitive applications.

  • Upgrade of alpha features like cStor Pools using new schema (CSPC), cStor CSI Driver, Jiva CSI Driver, and Mayastor are not supported.

  • A healthy volume(cStor or Jiva) which has a slow replica due to disk slowness or has huge network latency can cause volume read-only. In this case, a write IO to that slow replica takes more than 15-30 seconds to communicate with its controller which might cause disconnection from the initiator.

  • Overprovisioning is enabled by default on cStor volumes. In case of application such as ElasticSearch, Postgresql which uses ext4 filesystem without unmap support and when a data is written and modified, ext4 tends to use new blocks of storage without sending any delete (unmap) requests back to the underlying block storage - like cStor. This can be avoided by setting a configuration on storage class based on resource quota to set a limit on the sum of capacity allocated to all the PVCs to be within the available capacity of the underlying cStor Pools. Further details are tracked here.

  • cStor volume will be offline when ReplicationFactor is not greater than 50% and then cStor volume will not come online automatically and then reconstructing data to recovered replicas. It requires manual steps to make the volume online and reconstruct the data to the replaced replicas from a healthy replica once the cStor volume is online.

  • If a pending PVC related to openebs-device StorageClass is deleted, there are chances of getting stale BDCs which ends up consuming BDs. You have to manually delete the BDC to reclaim it.

  • In OpenShift 3.10 or above, NDM daemon set pods and NDM operators will not be upgraded if the NDM daemon set's DESIRED count is not equal to the CURRENT count. This may happen if nodeSelectors have been used to deploy OpenEBS related pods OR if master/other nodes have been tainted in the k8s cluster.

  • Jiva Controller and Replica pods are stuck in the Terminating state when any instability with the node or network happens and the only way to remove those containers is by using docker rm -f on the node. https://github.com/openebs/openebs/issues/2675

  • cStor Target or Pool pods can at times be stuck in a Terminating state. They will need to be manually cleaned up using kubectl delete with a 0 sec grace period. Example: kubectl delete deploy -n openebs --force --grace-period=0

  • cStor pool pods can consume more memory when there is continuous load. This can cross the memory limit and cause pod evictions. It is recommended that you create cStor pools by setting the Memory limits and requests.

  • Jiva Volumes are not recommended if your use case requires snapshots and clone capabilities.

  • Jiva Replicas use a sparse file to store the data. When the application causes too many fragments (extents) to be created on the sparse file, the replica restart can cause replica to take a longer time to get attached to the target. This issue was seen when there were 31K fragments created.

  • Jiva Replicas use a sparse file to store the data. On every restart of the controller or the replica, a new sparse file is created per replica. Long-running Jiva volumes can end up consuming more disk space as the number of sparse files per replica starts increasing.

  • Volume Snapshots are dependent on the functionality provided by Kubernetes. The support is currently alpha. The only operations supported are:

    • Create Snapshot, Delete Snapshot, and Clone from a Snapshot. The creation of the Snapshot uses a reconciliation loop, which would mean that a Create Snapshot operation will be retried on failure until the Snapshot has been successfully created. This may not be a desirable option in cases where Point in Time snapshots are expected.

  • If you are using the K8s version earlier than 1.12, in certain cases, it will be observed that when the node hosting the target pod is offline, the target pod can take more than 120 seconds to get rescheduled. This is because target pods are configured with Tolerations based on the Node Condition, and TaintNodesByCondition is available only from K8s 1.12. If running an earlier version, you may have to enable the alpha gate for TaintNodesByCondition. If there is an active load on the volume when the target pod goes offline, the volume will be marked as read-only.

  • If you are using K8s version 1.13 or later, that includes the checks on ephemeral storage limits on the Pods, there is a chance that OpenEBS cStor and Jiva pods can get evicted - because there are no ephemeral requests specified. To avoid this issue, you can specify the ephemeral storage requests in the storage class or storage pool claim. (https://github.com/openebs/openebs/issues/2294)

  • When the disks used by a cStor Pool are detached and reattached, the cStor Pool may miss detecting this event in certain scenarios. Manual intervention may be required to bring the cStor Pool online. (https://github.com/openebs/openebs/issues/2363)

  • When the underlying disks used by cStor or Jiva volumes are under disk pressure due to heavy IO load, and if the Replicas take longer than 60 seconds to process the IO, the Volumes will get into Read-Only state. In 0.8.1, logs have been added to the cStor and Jiva replicas to indicate if IO has longer latency. (https://github.com/openebs/openebs/issues/2337)

  • LocalPV RawBlock volumes are not supported when the application container is running in privileged mode.

  • An application may go into the read-only state during the Jiva upgrade if multipath support is enabled on the Nodes. It requires manual login of iscsi on the node where the application pod is running or scheduling of the application onto another node to make the application into running state.

Support

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