This topic describes the precautions for purchasing an Alibaba Cloud Elasticsearch cluster.
Subscription Elasticsearch clusters
Elasticsearch offers discounts based on subscription durations. After you purchase a subscription Elasticsearch cluster, you can request a refund within five days. Refunds are not provided five days after the data of purchase.
Elasticsearch provides a variety of specifications. The specifications of one vCPU and 2 GiB of memory are offered only for testing purposes. The service-level agreement (SLA) does not apply to clusters with the specifications. These specifications have lower configurations that may not meet the needs of production environments, which generally have high resource consumption. If you use the specifications to handle production workloads, your services may be affected. Therefore, do not use these specifications in product environments.
- If you are using an Elasticsearch cluster with such specifications in a production environment, we recommend that you perform a configuration upgrade to improve the stability and availability of your cluster. The upgrade may incur additional fees. For more information, see Pricing.
- Two vCPUs and 4 GiB of memory are the minimum specifications for an Elasticsearch cluster used in a production environment.
Disk sizes of Elasticsearch clusters
Before you determine the disk size of an Elasticsearch cluster, make sure that you understand the types of data that will be stored on the nodes in the cluster.
- User data that has been pushed to Elasticsearch.
- Index replicas. The number of index replicas is user-configurable. However, each index must have a minimum of one replica.
- Logs of your Elasticsearch cluster. The logs include operational logs, access logs, and slow logs. The amount of storage space that Elasticsearch consumes increases with the number of queries and data pushes that your Elasticsearch cluster receives. By default, Elasticsearch keeps only logs generated in the last seven days. The logs are not accessible to users.
- X-Pack monitoring indexes for troubleshooting. X-Pack is a plug-in of Elasticsearch.
The monitoring indexes include the following types:
Notice The higher the disk space occupied by Elasticsearch cluster logs and X-Pack monitoring indexes, the smaller the amount of remaining disk space.
- .monitoring-es-6-2018.01.08: This type of index consumes a large amount of storage space. By default, Elasticsearch keeps only index data that is created in the last seven days.
- .monitoring-kibana-6-2018.01.08: The amount of storage space consumed by this type of index increases with the number of indexes. By default, Elasticsearch keeps only index data that is created in the last seven days.
- .watcher-history-3-2018.01.08: This type of index consumes only a small amount of storage space. If such indexes are no longer required, you can manually delete these indexes.