Alibaba Cloud Elasticsearch provides four mechanisms to protect your data and keep your service available: data backup and restoration, load balancing, multi-zone deployment, and continuous kernel optimization.
Data backup and restoration
Three backup modes are available, each suited to a different recovery scenario:
| Mode | What it does | For more information |
|---|---|---|
| Automatic snapshots | Back up the full data of a cluster at a specified interval and point in time. Restore data from any automatic snapshot back to the original cluster. | Create automatic snapshots and restore data from automatic snapshots |
| Manual snapshots | Manually create a snapshot for a specific index and save it to an Object Storage Service (OSS) bucket in the same region. Restore to the original cluster or any cluster in the same region. | Create manual snapshots and restore data from manual snapshots |
| Shared OSS repository | Configure shared OSS snapshot repositories to restore data from automatic snapshots of another cluster to your cluster. | Configure a shared OSS repository |
Load balancing
Point your application to the cluster's public or internal endpoint. Elasticsearch distributes incoming requests evenly across all data nodes.
Load balancing effectiveness depends on the number and size of index shards. Set these to appropriate values when creating an index. See Shard evaluation.
Multi-zone deployment
Deploy a cluster across multiple zones so that your service remains available if one zone goes down. The system automatically selects which zones to use.
With replica shards configured, if nodes in one zone fail, the remaining zones continue serving requests without interruption. Two manual operations are available in the console to manage failures:
| Operation | When to use | What happens |
|---|---|---|
| Switchover | A zone experiences node failures | Isolates the faulty zone and adds computing resources to the remaining zones to compensate. Initiated from the Elasticsearch console. |
| Recovery | After faulty nodes are restored | Adds the recovered nodes back to the zone and removes the extra resources added during switchover. |
Both operations are transparent to running services and improve service stability. See Deploy and use a multi-zone Elasticsearch cluster.
AliES enhancements
The Alibaba Cloud Elasticsearch team continuously develops and optimizes the Elasticsearch kernel to improve cluster stability and availability. See Features supported by Kernel-enhanced Edition.