Chapter 4. Performing cross-site operations with the REST API

Data Grid Server provides a REST endpoint that exposes methods for performing cross-site operations.

4.1. Getting status of all backup locations

Retrieve the status of all backup locations with GET requests. 

GET /rest/v2/caches/{cacheName}/x-site/backups/

Data Grid responds with the status of each backup location in JSON format, as in the following example: 

{
  "NYC": {
    "status": "online"
  },
  "LON": {
    "status": "mixed",
    "online": [
      "NodeA"
    ],
    "offline": [
      "NodeB"
    ]
  }
}

Table 4.1. Returned Status

ValueDescription

online

All nodes in the local cluster have a cross-site view with the backup location.

offline

No nodes in the local cluster have a cross-site view with the backup location.

mixed

Some nodes in the local cluster have a cross-site view with the backup location, other nodes in the local cluster do not have a cross-site view. The response indicates status for each node.

4.2. Getting status of specific backup locations

Retrieve the status of a backup location with GET requests. 

GET /rest/v2/caches/{cacheName}/x-site/backups/{siteName}

Data Grid responds with the status of each node in the site in JSON format, as in the following example: 

{
  "NodeA":"offline",
  "NodeB":"online"
}

Table 4.2. Returned Status

ValueDescription

online

The node is online.

offline

The node is offline.

failed

Not possible to retrieve status. The remote cache could be shutting down or a network error occurred during the request.

4.3. Taking backup locations offline

Take backup locations offline with POST requests and the ?action=take-offline parameter. 

POST /rest/v2/caches/{cacheName}/x-site/backups/{siteName}?action=take-offline

4.4. Bringing backup locations online

Bring backup locations online with the ?action=bring-online parameter. 

POST /rest/v2/caches/{cacheName}/x-site/backups/{siteName}?action=bring-online

4.5. Pushing state to backup locations

Push cache state to a backup location with the ?action=start-push-state parameter. 

POST /rest/v2/caches/{cacheName}/x-site/backups/{siteName}?action=start-push-state

4.6. Canceling state transfer

Cancel state transfer operations with the ?action=cancel-push-state parameter. 

POST /rest/v2/caches/{cacheName}/x-site/backups/{siteName}?action=cancel-push-state

4.7. Getting state transfer status

Retrieve status of state transfer operations with the ?action=push-state-status parameter. 

GET /rest/v2/caches/{cacheName}/x-site/backups?action=push-state-status

Data Grid responds with the status of state transfer for each backup location in JSON format, as in the following example: 

{
   "NYC":"CANCELED",
   "LON":"OK"
}

Table 4.3. Returned status

ValueDescription

SENDING

State transfer to the backup location is in progress.

OK

State transfer completed successfully.

ERROR

An error occurred with state transfer. Check log files.

CANCELLING

State transfer cancellation is in progress.

4.8. Clearing state transfer status

Clear state transfer status for sending sites with the ?action=clear-push-state-status parameter. 

POST /rest/v2/caches/{cacheName}/x-site/local?action=clear-push-state-status

4.9. Modifying take offline conditions

Sites go offline if certain conditions are met. Modify the take offline parameters to control when backup locations automatically go offline.

Procedure

  1. Check configured take offline parameters with GET requests and the take-offline-config parameter. 

    GET /rest/v2/caches/{cacheName}/x-site/backups/{siteName}/take-offline-config

    The Data Grid response includes after_failures and min_wait fields as follows: 

    {
  "after_failures": 2,
  "min_wait": 1000
}

  2. Modify take offline parameters in the body of PUT requests. 

    PUT /rest/v2/caches/{cacheName}/x-site/backups/{siteName}/take-offline-config

    If the operation successfully completes, the service returns 204 (No Content).

4.10. Canceling state transfer from receiving sites

If the connection between two backup locations breaks, you can cancel state transfer on the site that is receiving the push.

Cancel state transfer from a remote site and keep the current state of the local cache with the ?action=cancel-receive-state parameter. 

POST /rest/v2/caches/{cacheName}/x-site/backups/{siteName}?action=cancel-receive-state

4.11. Getting status of backup locations

Retrieve the status of all backup locations from Cache Managers with GET requests. 

GET /rest/v2/cache-managers/{cacheManagerName}/x-site/backups/

Data Grid responds with status in JSON format, as in the following example: 

{
   "SFO-3":{
      "status":"online"
   },
   "NYC-2":{
      "status":"mixed",
      "online":[
         "CACHE_1"
      ],
      "offline":[
         "CACHE_2"
      ],
      "mixed": [
         "CACHE_3"
      ]
   }
}

Table 4.4. Returned status

ValueDescription

online

All nodes in the local cluster have a cross-site view with the backup location.

offline

No nodes in the local cluster have a cross-site view with the backup location.

mixed

Some nodes in the local cluster have a cross-site view with the backup location, other nodes in the local cluster do not have a cross-site view. The response indicates status for each node. 

GET /rest/v2/cache-managers/{cacheManagerName}/x-site/backups/{site}

Returns the status for a single backup location.

4.12. Taking backup locations offline

Take backup locations offline with the ?action=take-offline parameter. 

POST /rest/v2/cache-managers/{cacheManagerName}/x-site/backups/{siteName}?action=take-offline

4.13. Bringing backup locations online

Bring backup locations online with the ?action=bring-online parameter. 

POST /rest/v2/cache-managers/{cacheManagerName}/x-site/backups/{siteName}?action=bring-online

4.14. Retrieving the state transfer mode

Check the state transfer mode with GET requests. 

GET /rest/v2/caches/{cacheName}/x-site/backups/{site}/state-transfer-mode

4.15. Setting the state transfer mode

Configure the state transfer mode with the ?action=set parameter. 

POST /rest/v2/caches/{cacheName}/x-site/backups/{site}/state-transfer-mode?action=set&mode={mode}

4.16. Starting state transfer

Push state of all caches to remote sites with the ?action=start-push-state parameter. 

POST /rest/v2/cache-managers/{cacheManagerName}/x-site/backups/{siteName}?action=start-push-state

4.17. Canceling state transfer

Cancel ongoing state transfer operations with the ?action=cancel-push-state parameter. 

POST /rest/v2/cache-managers/{cacheManagerName}/x-site/backups/{siteName}?action=cancel-push-state