Asynchronous DR
Prerequisites
- Version: Portworx v2.1 or later needs to be installed on both clusters. Also requires Stork v2.2+ on both the clusters.
- Secret Store : Make sure you have configured a secret store on both your clusters. This will be used to store the credentials for the objectstore.
- Network Connectivity: Ports 9001 and 9010 on the destination cluster should be reachable by the source cluster.
- Stork helper:
storkctl
is a command-line tool for interacting with a set of scheduler extensions.Perform the following steps to download
storkctl
from the Stork pod:Linux:
STORK_POD=$(kubectl get pods -n kube-system -l name=stork -o jsonpath='{.items[0].metadata.name}') && kubectl cp -n kube-system $STORK_POD:/storkctl/linux/storkctl ./storkctl sudo mv storkctl /usr/local/bin && sudo chmod +x /usr/local/bin/storkctl
OS X:
STORK_POD=$(kubectl get pods -n kube-system -l name=stork -o jsonpath='{.items[0].metadata.name}') && kubectl cp -n kube-system $STORK_POD:/storkctl/darwin/storkctl ./storkctl sudo mv storkctl /usr/local/bin && sudo chmod +x /usr/local/bin/storkctl
Windows:
Copy
storkctl.exe
from the stork pod:STORK_POD=$(kubectl get pods -n kube-system -l name=stork -o jsonpath='{.items[0].metadata.name}') && kubectl cp -n kube-system $STORK_POD:/storkctl/windows/storkctl.exe ./storkctl.exe
Move
storkctl.exe
to a directory in your PATH
- Default Storage Class: Make sure you have configured only one default storage class. Having multiple default storage classes will cause PVC migrations to fail.
- License: You will need a DR enabled Portworx license at both the source and destination cluster to use this feature.
- If the destination cluster runs on GKE, follow the steps in the Migration with Stork on GKE page.
- If the destination cluster runs on EKS, follow the steps in the Migration with Stork on EKS page.
- An external objectstore, such as Minio s3, AWS s3, GCE Object Storage, or Azure Blob Storage, must be setup outside the Kubernetes clusters. If an external objectstore is not provided, Portworx will create an internal objectstore with a 100G backing volume. Pure Storage does not recommend using the internal objectstore in production.
Overview
With asynchronous DR, you can replicate Kubernetes applications and their data between two Kubernetes clusters. Here, a separate Portworx Enterprise cluster runs under each Kubernetes cluster.
- The active Kubernetes cluster asynchronously backs-up apps, configuration and data to a standby Kubernetes cluster.
- The standby Kubernetes cluster has running controllers, configuration and PVCs that map to a local volumes.
- Incremental changes in Kubernetes applications and Portworx data are continuously sent to the standby cluster.
The list of supported Kubernetes resources can be found here If a custom CR that you need is not present in this list, you can register a new one. Refer to the Application Registration document for instructions on how to do this.
Enable load balancing on cloud clusters
If you’re running Kubernetes on the cloud, you must configure an External LoadBalancer (ELB) for the Portworx API service.
Enable load balancing by entering the kubectl edit service
command and changing the service type value from nodePort
to loadBalancer
:
kubectl edit service portworx-service -n kube-system
kind: Service
apiVersion: v1
metadata:
name: portworx-service
namespace: kube-system
labels:
name: portworx
spec:
selector:
name: portworx
type: loadBalancer
Generate and Apply a ClusterPair Spec
In Kubernetes, you must define a trust object called ClusterPair. Portworx requires this object to communicate with the destination cluster. The ClusterPair object pairs the Portworx storage driver with the Kubernetes scheduler, allowing the volumes and resources to be migrated between clusters.
The ClusterPair is generated and used in the following way:
- The ClusterPair spec is generated on the destination cluster.
- The generated spec is then applied on the source cluster
Perform the following steps to create a cluster pair:
pxctl
commands in this document either on your Portworx nodes directly, or from inside the Portworx containers on your Kubernetes control plane node.
Create object store credentials for cloud clusters
You must create object store credentials on both the destination and source clusters before you can create a cluster pair. The options you use to create your object store credentials differ based on which object store you use:
Create Amazon s3 credentials
Find the UUID of your destination cluster
Enter the
pxctl credentials create
command, specifying the following:- The
--provider
flag with the name of the cloud provider (s3
). - The
--s3-access-key
flag with your secret access key - The
--s3-secret-key
flag with your access key ID - The
--s3-region
flag with the name of the S3 region (us-east-1
) - The
--s3-endpoint
flag with the name of the endpoint (s3.amazonaws.com
) - The optional
--s3-storage-class
flag with either theSTANDARD
orSTANDARD-IA
value, depending on which storage class you prefer clusterPair_
with the UUID of your destination cluster. Enter the following command into your cluster to find its UUID:PX_POD=$(kubectl get pods -l name=portworx -n kube-system -o jsonpath='{.items[0].metadata.name}') kubectl exec $PX_POD -n kube-system -- /opt/pwx/bin/pxctl status | grep UUID | awk '{print $3}'
/opt/pwx/bin/pxctl credentials create \ --provider s3 \ --s3-access-key <aws_access_key> \ --s3-secret-key <aws_secret_key> \ --s3-region us-east-1 \ --s3-endpoint s3.amazonaws.com \ --s3-storage-class STANDARD \ clusterPair_<UUID_of_destination_cluster>
- The
Create Microsoft Azure credentials
Find the UUID of your destination cluster
Enter the
pxctl credentials create
command, specifying the following:--provider
asazure
--azure-account-name
with the name of your Azure account--azure-account-key
with your Azure account keyclusterPair_
with the UUID of your destination cluster appended. Enter the following command into your cluster to find its UUID:PX_POD=$(kubectl get pods -l name=portworx -n kube-system -o jsonpath='{.items[0].metadata.name}') kubectl exec $PX_POD -n kube-system -- /opt/pwx/bin/pxctl status | grep UUID | awk '{print $3}'
/opt/pwx/bin/pxctl credentials create \ --provider azure \ --azure-account-name <your_azure_account_name> \ --azure-account-key <your_azure_account_key> \ clusterPair_<UUID_of_destination_cluster>
Create Google Cloud Platform credentials
Find the UUID of your destination cluster
Enter the
pxctl credentials create
command, specifying the following:--provider
asgoogle
--google-project-id
with the string of your Google project ID--google-json-key-file
with the filename of your GCP JSON key fileclusterPair_
with the UUID of your destination cluster appended. Enter the following command into your cluster to find its UUID:PX_POD=$(kubectl get pods -l name=portworx -n kube-system -o jsonpath='{.items[0].metadata.name}') kubectl exec $PX_POD -n kube-system -- /opt/pwx/bin/pxctl status | grep UUID | awk '{print $3}'
/opt/pwx/bin/pxctl credentials create \ --provider google \ --google-project-id <your_google_project_ID> \ --google-json-key-file <your_GCP_JSON_key_file> \ clusterPair_<UUID_of_destination_cluster>
Generate a ClusterPair on the destination cluster
To generate the ClusterPair spec, run the following command on the destination cluster:
storkctl generate clusterpair -n <migrationnamespace> <remotecluster>
Here, remotecluster
is the Kubernetes object that will be created on the source cluster representing the pair relationship, and migrationnamespace
is the Kubernetes namespace of the source cluster that you want to migrate to the destination cluster.
During the actual migration, you will reference this name to identify the destination of your migration.
apiVersion: stork.libopenstorage.org/v1alpha1
kind: ClusterPair
metadata:
creationTimestamp: null
name: remotecluster
namespace: migrationnamespace
spec:
config:
clusters:
kubernetes:
LocationOfOrigin: /etc/kubernetes/admin.conf
certificate-authority-data: <CA_DATA>
server: https://192.168.56.74:6443
contexts:
kubernetes-admin@kubernetes:
LocationOfOrigin: /etc/kubernetes/admin.conf
cluster: kubernetes
user: kubernetes-admin
current-context: kubernetes-admin@kubernetes
preferences: {}
users:
kubernetes-admin:
LocationOfOrigin: /etc/kubernetes/admin.conf
client-certificate-data: <CLIENT_CERT_DATA>
client-key-data: <CLIENT_KEY_DATA>
options:
<insert_storage_options_here>: ""
mode: DisasterRecovery
status:
remoteStorageId: ""
schedulerStatus: ""
storageStatus: ""
Save the resulting spec to a file named clusterpair.yaml
.
Get the destination cluster token
On the destination cluster, run the following command from one of the Portworx nodes to get the cluster token. You’ll need this token in later steps:
pxctl cluster token show
Insert Storage Options
To pair storage specifying the following fields in the options
section of your ClusterPair
:
ip
, with the IP address of the remote Portworx nodeport
, with the port of the remote Portworx nodetoken
, the token of the destination cluster obtained fom the previous step.mode
: by default, every seventh migration is a full migration. If you specifymode: DisasterRecovery
, then every migration is incremental. When doing a one time Migration (and not DR) this option can be skipped.
Using Rancher Projects with ClusterPair
Rancher has a concept of Projects that allow grouping of resources and Kubernetes namespaces. Depending on the resource and how it is created, Rancher adds the following label or annotation:
field.cattle.io/projectID: <project-short-UUID>
The projectID
uniquely identifies the project, and the annotation or label on the Kubernetes object provides a way to tie a Kubernetes object back to a Rancher project.
From version 2.11.2 or newer, Stork has the capability to map projects from the source cluster to the destination cluster when it migrates Kubernetes resources. It will ensure that the following are transformed
when migrating Kubernetes resources to a destination cluster:
* Labels and annotations for projectID field.cattle.io/projectID
on any Kubernetes resource on the source cluster are transformed to their respective projectIDs on the destination cluster.
* Namespace Selectors on a NetworkPolicy object which refer to the field.cattle.io/projectID
label will be transformed to their respective projectIDs on the destination cluster.
* Namespace Selectors on a Pod object (Kubernetes version 1.24 or newer) which refer to the field.cattle.io/projectID
label will be transformed to their respective projectIDs on the destination cluster.
NOTE:
- Rancher project mappings are supported only with Stork version 2.11.2 or newer.
- All the Rancher projects need to be created on both the source and the destination cluster.
While creating the ClusterPair, use the argument --project-mappings
to indicate which projectID on the source cluster maps to a projectID on the destination cluster.
For example:
storkctl generate clusterpair -n <migrationnamespace> <remotecluster> --project-mappings <projectID-A1>=<projectID-A2>,<projectID-B1>: <projectID-B2>
The project mappings are provided as a comma-separate key=value pairs. In this example, projectID-A1
on source cluster maps to projectID-A2
on the destination cluster, while projectID-B1
on the source cluster maps to projectID-B2
on the destination cluster.
Apply the ClusterPair spec on the source cluster
A typical ClusterPair spec should like the following once you have followed the previous steps
apiVersion: stork.libopenstorage.org/v1alpha1
kind: ClusterPair
metadata:
creationTimestamp: null
name: remotecluster
spec:
config:
clusters:
kubernetes:
LocationOfOrigin: /etc/kubernetes/admin.conf
certificate-authority-data: <CA_DATA>
server: https://192.168.56.74:6443
contexts:
kubernetes-admin@kubernetes:
LocationOfOrigin: /etc/kubernetes/admin.conf
cluster: kubernetes
user: kubernetes-admin
current-context: kubernetes-admin@kubernetes
preferences: {}
users:
kubernetes-admin:
LocationOfOrigin: /etc/kubernetes/admin.conf
client-certificate-data: <CLIENT_CERT_DATA>
client-key-data: <CLIENT_KEY_DATA>
options:
ip: <ip_of_remote_px_node>
port: <port_of_remote_px_node_default_9001>
token: <token_from_step_3>
mode: DisasterRecovery
platformOptions:
# This section will be set only when using Rancher
rancher:
projectMappings:
<projectID-A1>: <projectID-A2>
<projectID-B1>: <projectID-B2>
status:
remoteStorageId: ""
schedulerStatus: ""
storageStatus: ""
To create the ClusterPair, apply the ClusterPair YAML spec on the source cluster. Run the following command from a location where you have kubectl
access to the source cluster:
kubectl apply -f clusterpair.yaml -n <namespace>
Verify the ClusterPair
To verify that you have generated the ClusterPair and that it is ready, run the following command:
storkctl -n <namespace> get clusterpair
NAME STORAGE-STATUS SCHEDULER-STATUS CREATED
remotecluster Ready Ready 07 Mar 22 19:01 PST
On a successful pairing, you should see the STORAGE-STATUS
and SCHEDULER-STATUS
as Ready
.
If you see an error instead, you can get more information by running the following command:
kubectl describe clusterpair remotecluster -n <namespace>
Schedule a migration
To schedule a migration, you must create a schedule policy or a namespaced schedule policy. The NamespacedSchedulePolicy
is namespace-scoped while SchedulePolicy
is cluster-scoped.
Create a schedule policy
Paste the following content into a file called
testpolicy.yaml
:apiVersion: stork.libopenstorage.org/v1alpha1 kind: SchedulePolicy metadata: name: testpolicy policy: interval: intervalMinutes: 60 daily: time: "10:14PM" weekly: day: "Thursday" time: "10:13PM" monthly: date: 14 time: "8:05PM"
For details about how you can configure a schedule policy, see the Schedule Policy reference page.
Apply your spec by entering the following command:
kubectl apply -f testpolicy.yaml
Display your schedule policy. Enter the
storkctl get
command passing it the name of your policy:storkctl get schedulepolicy
NAME INTERVAL-MINUTES DAILY WEEKLY MONTHLY testpolicy 60 10:14PM Thursday@10:13PM 14@8:05PM
Create a namespaced schedule policy
Paste the following content into a file called
namespaced-testpolicy.yaml
:apiVersion: stork.libopenstorage.org/v1alpha1 kind: NamespacedSchedulePolicy metadata: name: testpolicy namespace: <namespace-for-sched-policy> policy: interval: intervalMinutes: 60 daily: time: "10:14PM" weekly: day: "Thursday" time: "10:13PM" monthly: date: 14 time: "8:05PM"
Apply your spec by entering the following command:
kubectl apply -f namespaced-testpolicy.yaml
Display your namespacedschedule policy. Enter the
kubectl -n <namespace-for-sched-policy> get
command passing it the name of your policy:kubectl -n <namespace-for-sched-policy> get namespacedschedulepolicy
NAME AGE testpolicy 1s
Create a migration schedule
Once a schedule policy or namespaced schedule policy has been created, you can use it to schedule a migration. The spec for the MigrationSchedule spec contains the same fields as the Migration spec with the addition of the policy name. The MigrationSchedule object is namespaced like the Migration object. Stork will first look for namespaced schedule policy in the same namespace of migration/backup. If a namespaced schedule policy with the specified name is not found it will look for global SchedulePolicy with the same name.
Note that startApplications
should be set to false in the spec. Otherwise, the first Migration will start the pods on the remote cluster and will succeed. But all subsequent migrations will fail since the volumes will be in use.
pxctl cluster migrate
command.
Continuing our previous example with testpolicy
, here is how to create a MigrationSchedule
object that schedules a migration:
apiVersion: stork.libopenstorage.org/v1alpha1
kind: MigrationSchedule
metadata:
name: mysqlmigrationschedule
namespace: mysql
spec:
template:
spec:
clusterPair: remotecluster
includeResources: true
startApplications: false
namespaces:
- mysql
schedulePolicyName: testpolicy
If the policy name is missing or invalid there will be events logged against the schedule object. Success and failures of the migrations created by the schedule will also result in events being logged against the object. These events can be seen by running a kubectl describe
on the object
The output of kubectl describe
will also show the status of the migrations that were triggered for each of the policies along with the start and finish times. The statuses will be maintained for the last successful migration and any Failed or InProgress migrations for each policy type.
Let’s now run kubectl describe
and see how the output would look like:
kubectl describe migrationschedules.stork.libopenstorage.org -n mysql
Name: mysqlmigrationschedule
Namespace: mysql
Labels: <none>
Annotations: kubectl.kubernetes.io/last-applied-configuration:
{"apiVersion":"stork.libopenstorage.org/v1alpha1","kind":"MigrationSchedule","metadata":{"annotations":{},"name":"mysqlmigrationschedule",...
API Version: stork.libopenstorage.org/v1alpha1
Kind: MigrationSchedule
Metadata:
Creation Timestamp: 2019-02-14T04:53:58Z
Generation: 1
Resource Version: 30206628
Self Link: /apis/stork.libopenstorage.org/v1alpha1/namespaces/mysql/migrationschedules/mysqlmigrationschedule
UID: 8a245c1d-3014-11e9-8d3e-0214683e8447
Spec:
Schedule Policy Name: daily
Template:
Spec:
Cluster Pair: remotecluster
Include Resources: true
Namespaces:
mysql
Post Exec Rule:
Pre Exec Rule:
Selectors: <nil>
Start Applications: false
Status:
Items:
Daily:
Creation Timestamp: 2019-02-14T22:16:51Z
Finish Timestamp: 2019-02-14T22:19:51Z
Name: mysqlmigrationschedule-daily-2019-02-14-221651
Status: Successful
Interval:
Creation Timestamp: 2019-02-16T00:40:52Z
Finish Timestamp: 2019-02-16T00:41:52Z
Name: mysqlmigrationschedule-interval-2019-02-16-004052
Status: Successful
Creation Timestamp: 2019-02-16T00:41:52Z
Finish Timestamp: <nil>
Name: mysqlmigrationschedule-interval-2019-02-16-004152
Status: InProgress
Monthly:
Creation Timestamp: 2019-02-14T20:05:41Z
Finish Timestamp: 2019-02-14T20:07:41Z
Name: mysqlmigrationschedule-monthly-2019-02-14-200541
Status: Successful
Weekly:
Creation Timestamp: 2019-02-14T22:13:51Z
Finish Timestamp: 2019-02-14T22:16:51Z
Name: mysqlmigrationschedule-weekly-2019-02-14-221351
Status: Successful
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Successful 4m55s (x53 over 164m) stork (combined from similar events): Scheduled migration (mysqlmigrationschedule-interval-2019-02-16-003652) completed successfully
Each migration is associated with a Migrations object. To get the most important information, type:
kubectl get migration -n mysql
NAME AGE
mysqlmigrationschedule-daily-2019-02-14-221651 1d
mysqlmigrationschedule-interval-2019-02-16-004052 5m
mysqlmigrationschedule-interval-2019-02-16-004152 4m
mysqlmigrationschedule-monthly-2019-02-14-200541 1d
mysqlmigrationschedule-weekly-2019-02-14-221351 1d
Once the MigrationSchedule object is deleted, all the associated Migration objects should be deleted as well.
Failover an application
For instructions on how to failover an application, follow the steps from Metro DR to Stop the application on the source cluster and then Start the application on the destination cluster.
Clean up disaster recovery objects
If you no longer require a disaster recovery object, you can delete it.
To delete a migration schedule, run the following command:
kubectl delete migrationschedule mysqlmigrationschedule -n mysql
To delete a namespaced
policy, run the following command:
kubectl delete namespacedschedulepolicy testpolicy -n mysql
To delete a cluster pair, run the following command:
kubectl delete clusterpair remotecluster -n mysql
Supported Kubernetes Resources
The Asynchronous DR feature supports the following Kubernetes resources:
- PersistentVolumeClaim
- PersistentVolume
- Deployment
- DeploymentConfig
- StatefulSet
- ConfigMap
- Service
- Secret
- DaemonSet
- ServiceAccount
- Role
- RoleBinding
- ClusterRole
- ClusterRoleBinding
- ImageStream
- Ingress
- Route
- Template
- CronJob
- ResourceQuota
- ReplicaSet
- LimitRange
- PodDisruptionBudget
- NetworkPolicy
CIDR
set. To migrate NetworkPolicies which have CIDR
set, use the skipNetworkPolicyCheck: true
flag in the Migration object.
Asynchronous DR also supports the following CRDs out-of-the-box:
- CassandraDatacenter
- CouchbaseBucket
- CouchbaseCluster
- CouchbaseEphemeralBucket
- CouchbaseMemcachedBucket
- CouchbaseReplication
- CouchbaseUser
- CouchbaseGroup
- CouchbaseRoleBinding
- CouchbaseBackup
- CouchbaseBackupRestore
- IBPCA
- IBPConsole
- IBPOrderer
- IBPPeer
- RedisEnterpriseCluster
- RedisEnterpriseDatabase