# Assigning Remote Engines to clusters
It is recommended to only add Remote Engines with the same version to a cluster.
In addition, if you have specified an engine to use a specific Java version to run tasks and plans, ensure to configure the same version for all the engines in the same cluster; otherwise, unexpected issues may occur at runtime.
For further information about how to configure Java versions for task and plan executions, see [Configuring Java versions to run Jobs or Microservices](https://help.qlik.com/talend/en-US/remote-engine-user-guide-linux/Cloud/configure-java-versions-for-job-execution-or-microservice-execution "Configure your Talend Remote Engine to execute Jobs or Microservices using the appropriate Java version based on each artifact Java compatibility level.").
## About this task
Information noteNote: If a Route or data service is deployed on an engine you want to add to the cluster, you must first undeploy the task, then add the engine to the cluster and redeploy the task on the engine cluster.
## Procedure
1. Open the Processing page then click the Engines tab.
2. Click the name of cluster to which you want to add Remote Engines.
If this cluster already contains some engines, details about the engine availability is displayed on this list as well as on the Cluster details blade.
To verify the Java version each engine uses, click the engine to open its Engine details blade, and then click the Configuration tab.
3. Click the  icon on the Engines tab.
### Example
4. Select the Remote Engines to include in the cluster.
You can only select Remote Engines from the same environment where your cluster is.
You can select Remote Engines from any space on that environment. However, if the spaces are different, the selected Remote Engines will be placed into the cluster's space.
Information noteNote: When deploying Routes and data services on a cluster, all Remote Engines assigned to it must be of the same version (v2.8.4 or above).
5. If Job tasks are already running or scheduled on the Remote Engine you selected, choose your preferred option to update the cluster's run profile.
You can reschedule the tasks running on the engine to run on the cluster:
* Without a run profile
* By duplicating the engine run profiles and associating them with the cluster
* Using the cluster run profile
## Results
The number of engines belonging to a cluster appears in brackets next to its name on the Engines tab of the Processing page.
When choosing to run a Job task on the cluster, it is executed in a round-robin manner on the engines belonging to the cluster. The task is executed on the first available Remote Engine, then the next and so on, while putting the ones the task was executed on to the end of the list. If a Remote Engine is not available, the task is executed on the next available engine.
When choosing to run a data service or Route task on the cluster, you must define a deployment strategy.
Two deployment strategies are available when running a data service or Route task on the clusterTwo deployment strategies are available when running a data service or Route task on the cluster
| Parallel | The tasks are deployed simultaneously to all the Remote Engines of
the cluster. Before deploying a new version of a task, you will need to
undeploy the currently running version, which will result in service
interruption. |
| --- | --- |
| Rolling | If the Remote Engine cluster contains more than one Remote Engine,
the tasks are deployed one by one to the Remote Engines of the cluster.
This means that for a short time, different Remote Engines will be
running different versions of the task, therefore you can avoid service
interruption. |