Restoring in multiple regions

This page describes how to restore Cassandra in multiple regions.

In a multi-region deployment, Apigee hybrid is deployed in multiple geographic locations across different datacenters. It is important to note that, if you have multiple Apigee organizations in your deployment, the restore process restores data for all the organizations. In a multi-organization setup, restoring only a specific organization is not supported.

Restoring cassandra

In a multi-region deployment, there are two possible ways to salvage a failed region. This topic describes the following approaches:

Recover failed region(s) - Describes the steps to recover failed region(s) based on a healthy region.
Restore failed region(s) - Describes the steps to restore failed region(s) from a backup. This approach is only required if all hybrid regions are impacted.

Recover failed region(s)

To recover failed region(s) from a healthy region, perform the following steps:

Redirect the API traffic from the impacted region(s) to the good working region. Plan the capacity accordingly to support the diverted traffic from failed region(s).
Decommission the impacted region. For each impacted region, follow the steps outlined in Decommission a hybrid region. Wait for decommissioning to complete before moving on to the next step.
Restore the impacted region. To restore, create a new region, as described in Multi-region deployment on GKE, GKE on-prem, and AKS.

Restoring from a backup

Note: If you want to preserve an existing setup for troubleshooting and root cause analysis (RCA), you should delete all the org and env components from the Kubernetes cluster except the Apigee controller, and retain the cluster. The cluster will contain the existing Apigee datastore (Cassandra) which you can use for troubleshooting. Create a new Kubernetes cluster and then restore Cassandra in the new cluster.

The Cassandra backup can either reside on Cloud Storage or on a remote server based on your configuration. To restore Cassandra from a backup, perform the following steps:

Delete apigee hybrid deployment from all the regions:
```
apigeectl delete -f overrides.yaml
```
Restore the desired region from a backup. For more information, see Restoring a region from a backup.
Remove the deleted region(s) references and add the restored region(s) references in the KeySpaces metadata.

Get the region name by using the nodetool status option.

kubectl exec -n apigee -it apigee-cassandra-default-0 -- bash
      nodetool  -u ${APIGEE_JMX_USER} -pw ${APIGEE_JMX_PASSWORD} status |grep -i Datacenter

Update the KeySpaces replication.
1. Create a client container and connect to the Cassandra cluster through the CQL interface.
2. Get the list of user keyspaces from CQL interface:
```
cqlsh ${CASSANDRA_SEEDS} -u ${CASS_USERNAME} -p ${CASS_PASSWORD}
            --ssl -e "select keyspace_name from system_schema.keyspaces;"|grep -v system
```
3. For each keyspace, run the following command from the CQL interface to update the replication settings:
```
ALTER KEYSPACE KEYSPACE_NAME WITH replication = {'class': 'NetworkTopologyStrategy', 'REGION_NAME':3};
```
  where:
  - KEYSPACE_NAME is the name of the keyspace listed in the previous step's output.
  - REGION_NAME is the region name obtained in Step 4.