Premium HA - Data center disaster recovery from backup
Dynatrace Premium High Availability (Premium HA) is a self-contained, out-of-the-box solution that provides near-zero downtime and allows monitoring to continue without data loss in failover scenarios. This solution requires additional licensing for your deployment.
In this recovery procedure, the following terms are designated as follows:
- Source-DC - Source (surviving) data center where the Managed cluster is located.
- Target-DC - Target (lost) data center designated for recovery.
- seed node - Any node within Source-DC that will be used for performing the installation tasks and distribution of configuration.
The procedure involves migration and replication of Dynatrace Managed components separately so they are prepared for data replication across two data centers. See Overview of Dynatrace Managed components.
Uninstall Dynatrace Managed on all running nodes
Restore data center from backup
Remove lost data center from configuration
Distribute the installer
Prepare cluster data for a replication
Create the data center topology
Open firewall rules
Install second data center nodes
Migrate Cassandra
Migrate Elasticsearch
Migrate the server
Enable the new data center
Gather information
The commands will use these variables in executing the REST API calls. For this, you will need the following information:
-
<seed-node-ip>- The IP address of the seed node from Source-DC.
This can be any node running in existing data center that will be used for performing the installation tasks and distribution of configuration. -
<nodes-ips>- The list of IPV4 addresses of new nodes in Target-DC.
Example:"176.16.0.5", "176.16.0.6", "176.16.0.7" -
<api-token>- A valid Cluster API token (ServiceProviderAPI scope is required).
You can generate it in the Dynatrace Managed Cluster Management Console. See Cluster API - Authentication. -
<dynatrace-directory>- The directory where Dynatrace Managed is installed on the seed node.
The default Dynatrace Managed installation directory is/opt/dynatrace-managed -
<datacenter-1>- The Source-DC name must be the same as the Cassandra DC name.
The default Cassandra DC name isdatacenter1.To get the DC name, execute this command on the seed node before starting migration:
sudo <dynatrace-directory>/utils/cassandra-nodetool.sh statusYou will get a response that includes the Source-DC name. Example for a DC named
datacenter1:Datacenter: datacenter1=======================Status=Up/Down|/ State=Normal/Leaving/Joining/Moving-- Address Load Tokens Owns (effective) Host ID RackUN 10.176.42.20 65.54 GB 256 100.0% f053dd8d-ecf3-7834-b099-68542439817b rack1UN 10.176.42.244 65.47 GB 256 100.0% 2aa7e790-a423-9273-88f9-45bcd158dd6e rack1UN 10.176.42.168 65.47 GB 256 100.0% 48543bca-41f5-26d3-b2fd-6cfdf5c0f3b2 rack1 -
<datacenter-2>- The Target-DC name must remain unchanged. Example:dc-us-east-2.
You must use the same name of the lost data center during the recovery to Target-DC.
Set variables
Set the following environment variables on seed node in Source-DC and EACH NODE in Target-DC:
SEED_IP=<seed-ip>DT_DIR=<dynatrace-directory>NODES_IPS=$(echo '[<nodes-ips]')API_TOKEN=<api-token>SDC_NAME=<datacenter-1>TDC_NAME=<datacenter-2>
For example:
SEED_IP=10.176.37.201DT_DIR=/opt/dynatrace-managedNODES_IPS=$(echo '["10.176.37.218", "10.176.37.227", "10.176.37.120"]')API_TOKEN=R_SZOpV4RTOmjr9fFmK4xSDC_NAME=datacenter1TDC_NAME=dc-us-east-2
Check for custom settings
If your Cassandra or Elasticsearch cluster is configured with custom.settings that enable rack-awareness, contact a Dynatrace product expert via live chat to apply these custom settings before proceeding with Target-DC installation.
To check whether custom settings are applied, execute on seed node:
ls $DT_DIR/installer/custom.settings
If the custom.settings file exists, you are using custom settings.
Each of the REST API calls will return the HTTP code. Go to the next step only when the returned code is 200. Expect the following return codes:
200 - Go to the next step, current step was executed successfully.
207 - The request is being processed, repeat a step after few minutes.
40x - Revise your request path and arguments and repeat the request.
5xx - Contact support.
Uninstall Dynatrace Managed on all running nodes
Follow the official procedure to remove a cluster node using either the command prompt or the Cluster Management Console. See Remove a cluster node.
Restore data center from backup
Follow the official procedure to restore the data center from the backup. See Back up and restore a cluster.
Remove lost data center from configuration
Execute the following cluster API call only on the seed node:
curl -ikS -X POST https://$SEED_IP/api/v1.0/onpremise/multiDc/migration/lostDatacenterCleanUp?Api-Token=$API_TOKEN -H "accept: application/json" -H "Content-Type: application/json"
If the status code is not 200 and the response does not suggest next steps, contact a Dynatrace product expert via live chat.
Distribute the installer
In this step, you will copy the node installer to every node in Target-DC.
-
Log into your Dynatrace Managed Cluster Management Console.
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Go to Home for the Dynatrace Managed deployment status page.
-
Click Add new cluster node.
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Copy the
wgetcommand line from the Run this command on the target host text box.Do not run the installer scriptThe Run this installer script with root rights text box contains a command for the installation script. Ignore this command; do not execute the provided script.
-
Paste and execute only the
wgetcommand line into every node in Target-DC terminal window.
Prepare cluster data for a replication
In this step, you will prepare data indexes for replication.
Prepare cluster data
Execute the following cluster API call only on the seed node:
curl -ikS -X POST https://$SEED_IP/api/v1.0/onpremise/multiDc/migration/clusterReplicationPreparation?Api-Token=$API_TOKEN
If the status code is not 200 and the response does not suggest next steps, contact a Dynatrace product expert via live chat.
Check cluster preparation status
Execute the following cluster API call only on the seed node:
curl -ikS -X GET https://$SEED_IP/api/v1.0/onpremise/multiDc/migration/clusterReplicationPreparation?Api-Token=$API_TOKEN -H "accept: application/json"
If the status code from this call is not 200, try again after a few minutes.
Create the data center topology
In this step, you will create configuration that maintains which nodes belong to which data center.
Execute the following cluster API call only on the seed node:
curl -ikS -X POST -d "{\"newDatacenterName\" : \"$TDC_NAME\", \"nodesIp\" :$NODES_IPS}" https://$SEED_IP/api/v1.0/onpremise/multiDc/migration/datacenterTopology?Api-Token=$API_TOKEN -H "accept: application/json" -H "Content-Type: application/json"
If the status code is not 200 and the response does not suggest next steps, contact a Dynatrace product expert via live chat.
Open firewall rules
In this step, you will add firewall rules that open ports to traffic from the Target-DC nodes.
Open ports
To open ports to traffic from the new Target-DC nodes, execute the following cluster API call only on the seed node:
curl -ikS -X POST -d "$NODES_IPS" https://$SEED_IP/api/v1.0/onpremise/multiDc/migration/clusterNodes/currentDc?Api-Token=$API_TOKEN -H "accept: application/json" -H "Content-Type: application/json"
If successful, status code will be 200 and the response body will contain a request ID you need to check the firewall rules status.
If the status code is not 200 and the response does not suggest next steps, contact a Dynatrace product expert via live chat.
Verify firewall rules
Set the request ID environment variable on seed node only. The request ID is from the response in the previous API call.
REQ_ID=<topology-configuration-request-id>
To check the firewall rules status, execute the following cluster API call only on the seed node:
curl -ikS https://$SEED_IP/api/v1.0/onpremise/multiDc/migration/clusterNodes/currentDc/$REQ_ID?Api-Token=$API_TOKEN -H "accept: application/json" -H "Content-Type: application/json"
If the status code from this call is not 200, try again after a few minutes.
Install second data center nodes
In this step, you will install managed nodes on all hosts within Target-DC and once completed, you will check for the presence of a Nodekeeper service. This will indicate if all nodes were successfully installed in Target-DC.
Install nodes in Target-DC
Execute the following command on every node in Target-DC. Follow the on-screen instructions as this will be a typical node installation.
sudo /bin/sh ./managed-installer.sh --install-new-dc --premium-ha on --datacenter $TDC_NAME --seed-auth $API_TOKEN
This operation should take about 3-5 minutes and the expected result should be similar to this:
Installation in new data center completed successfully after 2 minutes 51 seconds.
Check Nodekeeper in Target-DC
Execute the following cluster API call only on the seed node when all nodes in Target-DC finish installing:
curl -ikS https://$SEED_IP/api/v1.0/onpremise/multiDc/migration/nodekeeper/healthCheck?Api-Token=$API_TOKEN -H "accept: application/json" -H "Content-Type: application/json"
If the status code is not 200, try again after a few minutes.
Migrate Cassandra
In this step, you will reconfigure Cassandra in Source-DC and Target-DC for cross data center replication, trigger data synchronization, rebuild Cassandra data and verify Cassandra state.
It may take minutes to hours depending on your metric storage size.
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Migration of Cassandra in Target-DC
In this step, you will reconfigure Cassandra for cross data center replication and trigger data synchronization.
Migrate Cassandra
To start migration of Cassandra in the Target-DC data center, execute the following cluster API call only on the seed node:
curl -ikS -X POST https://$SEED_IP/api/v1.0/onpremise/multiDc/migration/cassandra/newDc?Api-Token=$API_TOKEN -H "accept: application/json" -H "Content-Type: application/json"If successful, status code will be
200and the response body will contain a request ID which you need to check migration status. Set the request ID environment variable only on the seed node. The request ID is from the response in the previous API call.REQ_ID=<migration-new-datacenter-request-id>If status code is not
200and response does not suggest next steps, contact a Dynatrace product expert via live chat.Check migration status
To check the migration status, execute the following cluster API call only on the seed node:
curl -ikS -X GET https://$SEED_IP/api/v1.0/onpremise/multiDc/migration/cassandra/newDc/$REQ_ID?Api-Token=$API_TOKEN -H "accept: application/json" -H "Content-Type: application/json"If the status code is not
200, try again after few minutes. -
Rebuild Cassandra data
In this step, you will rebuild Cassandra, verify the progress by checking the status. Depending on the size of your Cassandra database, can take several hours.
Rebuild data
To rebuild Cassandra, run the following command on each new Target-DC node successively. Use the
nohupcommand to prevent interruption of script execution (such as session disconnect) during important operations.sudo nohup $DT_DIR/utils/cassandra-nodetool.sh rebuild -- $SDC_NAME &Verify progress and status
To verify the progress and status, execute the following cluster API call only on the seed node:
curl -ikS -X GET https://$SEED_IP/api/v1.0/onpremise/multiDc/migration/cassandra/rebuildStatus?Api-Token=$API_TOKEN -H "accept: application/json" -H "Content-Type: application/json"If the status code is not
200, try again after approximately 15 minutes. Remember that the rebuild process can be time-consuming.Verify Cassandra state
To verify Cassandra cluster state, execute the
cassandra-nodetool.shwith thestatusparameter only on the seed node:sudo $DT_DIR/utils/cassandra-nodetool.sh statusThe result should look similar to this:
Datacenter: dc1===============Status=Up/Down|/ State=Normal/Leaving/Joining/Moving-- Address Load Tokens Owns (effective) Host ID RackUN 10.176.41.167 18.82 GB 256 100.0% 3af25127-4f99-4f43-afc3-216d7a2c10f8 rack1UN 10.176.41.154 19.44 GB 256 100.0% 5a618559-3a73-42ec-83f0-32d28e08beec rack1UN 10.176.41.43 19.58 GB 256 100.0% 191f3b30-949a-4cf2-b620-68a40eebf31e rack1Datacenter: dc2===============Status=Up/Down|/ State=Normal/Leaving/Joining/Moving-- Address Load Tokens Owns (effective) Host ID RackUN 10.176.42.54 19.18 GB 256 100.0% 852ce236-a430-400a-92a6-daeed99acf68 rack1UN 10.176.42.104 19.12 GB 256 100.0% 84479219-b64d-442c-a807-a832db9aae18 rack1UN 10.176.42.234 19.4 GB 256 100.0% 507b377c-5bfc-4667-b251-a9b7c453ed22 rack1The Load value should not differ significantly between the nodes and Status should be
UNon all nodes.In this step, you will rebuild Cassandra and verify the progress by checking the status. Depending on the size of your Cassandra database, this can take several hours.
Rebuild data
To rebuild Cassandra data in the Target-DC data center, execute the following cluster API call only on the seed node:
curl -ikS -X POST https://$SEED_IP/api/v1.0/onpremise/multiDc/migration/cassandra/rebuild?Api-Token=$API_TOKEN -H "accept: application/json" -H "Content-Type: application/json"If successful, the status code will be
200. If the status code is not200and the response does not suggest the following steps, contact a Dynatrace product expert via live chat within your Dynatrace environment.Check the rebuild data status
To check the rebuild data status, execute the following cluster API call only on the seed node:
curl -ikS -X GET https://$SEED_IP/api/v1.0/onpremise/multiDc/migration/cassandra/rebuild?Api-Token=$API_TOKEN -H "accept: application/json" -H "Content-Type: application/json"If the status code is not
200, try again after approximately 15 minutes. Remember that the rebuilding data process can be time consuming.If the response has an error flag set to
true, contact a Dynatrace product expert via live chat within your environment.
Migrate Elasticsearch
In this step, you will migrate Elasticsearch to the Target-DC data center, verify the configuration and data migration. This step may take minutes or hours depending on your Elasticsearch storage.
Migrate Elasticsearch to Target-DC
Start Elasticsearch. Execute the following command successively on every node in Target-DC only:
sudo $DT_DIR/launcher/elasticsearch.sh start
To start migration of Elasticsearch to the Target-DC data center, execute the following cluster API call only on the seed node:
curl -ikS -X POST https://$SEED_IP/api/v1.0/onpremise/multiDc/restore/elasticsearch/recover?Api-Token=$API_TOKEN -H "accept: application/json" -H "Content-Type: application/json"
If successful, status code will be 200.
Verify progress and status
To check the migration status of Elasticsearch, execute the following cluster API call only on the seed node:
curl -ikS -X GET https://$SEED_IP/api/v1.0/onpremise/multiDc/restore/elasticsearch/recover?Api-Token=$API_TOKEN -H "accept: application/json" -H "Content-Type: application/json"
If the status code is not 200, try again after a few minutes.
Verify data migration
To verify migration Elasticsearch data migration, execute the following cluster API call only on the seed node:
curl -ikS -X GET https://$SEED_IP/api/v1.0/onpremise/multiDc/migration/elasticsearch/indexMigrationStatus?Api-Token=$API_TOKEN -H "accept: application/json" -H "Content-Type: application/json"
If the status code is not 200, try again after a few minutes.
Migrate the server
In this step, you will migrate the server, refresh authorization tokens that enable OneAgent connectivity, and start NGINX in the Target-DC data center. Also, you will refresh installers in Source-DC that are used to add nodes.
Migrate server
Launch the Dynatrace Managed cluster in the Target-DC by executing the following cluster API call only on the seed node:
curl -ikS -X POST https://$SEED_IP/api/v1.0/onpremise/multiDc/restore/server/recovery?Api-Token=$API_TOKEN -H "accept: application/json" -H "Content-Type: application/json"
If successful, status code will be 200 and the response body will contain a request ID which you need to check cluster readiness. Set the request ID environment variable only on the seed node. The request ID is from the response in the previous API call.
REQ_ID=<migration-server-request-id>
If status code is not 200 and response does not suggest next steps, contact a Dynatrace product expert via live chat.
Check cluster readiness
To check if the cluster is ready, execute the following cluster API call only on the seed node:
curl -ikS -X GET https://$SEED_IP/api/v1.0/onpremise/multiDc/restore/server/recovery/$REQ_ID?Api-Token=$API_TOKEN -H "accept: application/json" -H "Content-Type: application/json"
If the status code is not 200, try again after a few minutes.
Enable the new data center
- Enable OneAgent traffic.
For details, see Enable/Disable a cluster node. - Enable backup in one of the data centers. Your backup is disabled after migration.
For details, see Back up and restore a cluster.