When you stop routing requests or pause Elasticsearch cluster nodes, you can perform corrective actions that might otherwise be difficult to complete. For example, if your cluster is being overwhelmed by requests because it is undersized for its workload, its nodes might not respond to efforts to resize. Think of these actions as a maintenance mode for cluster nodes that can stop the cluster from becoming completely unresponsive, so that you can resolve operational issues much more effectively.
In this maintenance mode, requests to your cluster are blocked during configuration changes. You use maintenance mode to perform corrective actions that might otherwise be difficult to complete.
We strongly recommend that you use maintenance mode when your cluster is overwhelmed by requests and you need to increase capacity. If your cluster is being overwhelmed because it is undersized for its workload, nodes might not respond to efforts to resize. Putting the cluster into maintenance mode as part of the configuration change can stop the cluster from becoming completely unresponsive during the configuration change, so that you can resolve the capacity issue. Without this option, configuration changes for clusters that are overwhelmed can take longer and are more likely to fail.
What these actions accomplish:
- Stop routing: No new requests are routed to the cluster node, but existing requests are permitted to be completed. A gentler, less invasive action than pausing the cluster.
- Pause instance: Suspends the node immediately by stopping the Docker container that the node runs on without completing existing requests. A more direct, aggressive action to regain control of an unresponsive node.
To perform one of these actions on a cluster node:
- Log into the Cloud UI.
On the Deployments page, select your deployment.
Narrow the list by name, ID, or choose from several other filters. To further define the list, use a combination of filters.
- Select Stop routing or Pause instance for one of the nodes. Repeat for additional nodes in the cluster, if necessary.
Additionally, you can override the RAM to storage disk capacity for a deployment if your deployment is unhealthy or at capacity. By opening the Disk Quota Override window and changing the ratio, you can update all of the nodes in the deployment that have the same instance type. If the cluster is overwhelmed by requests, you can resize the deployment. After that, new cluster nodes start accepting requests again automatically. For other corrective actions, select Start routing or Resume instance after your changes are complete.