This topic describes the issues to consider before you purchase an Alibaba Cloud Elasticsearch instance.

Considerations of purchasing a subscription-based Elasticsearch instance

Discounts are offered on subscription-based Alibaba Cloud Elasticsearch instances based on the subscription duration.

You can request a refund within five days after you have purchased a subscription-based Elasticsearch instance. Refunds are not supported after five days from the date of purchase.

Considerations of purchasing an Elasticsearch instance

Currently, Alibaba Cloud Elasticsearch provides multiple instance specifications. The 1-core 2 GB specification is only for testing purposes. The specification is not covered under our Service Level Agreement (SLA). Do not use Elasticsearch instances of this specification in a production environment. A production environment always requires high resource consumption. This specification provides a low configuration, which may cause service instability in a production environment.

  • If you have purchased a 1-core 2 GB instance and the instance is being used in a production environment, we recommend that you perform a Cluster upgrade to improve the stability and availability of your services. When you upgrade a cluster, additional fees may be charged. For more information, see Pricing.
  • The minimum specification for an Elasticsearch instance used in a production environment is 2-core 4 GB.

Considerations of purchasing disks for Elasticsearch instances

Before you determine the size of the disks purchased for your Elasticsearch instance, make sure that you understand the types of data that will be stored in Elasticsearch.

Alibaba Cloud Elasticsearch is used to store the following types of data:
  • 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.
  • Alibaba Cloud Elasticsearch cluster logs, including the operation log, access log, and slow log. The amount of storage space that Elasticsearch consumes increases with the number of queries and pushes that Elasticsearch has received. By default, Elasticsearch only retains log data generated in the last seven days. Cluster logs currently are not accessible to users.
  • X-Pack monitoring indexes for troubleshooting. X-Pack is a plug-in of Alibaba Cloud Elasticsearch. Monitoring indexes include the following:
    • .monitoring-es-6-2018.01.08: The indexes consume a large amount of storage space. By default, Elasticsearch only keeps indexes created in the last seven days.
    • .monitoring-kibana-6-2018.01.08: The amount of storage space that the indexes consume increases with the number of the indexes. By default, Elasticsearch only keeps indexes created in the last seven days.
    • .watcher-history-3-2018.01.08: The indexes consume only a small amount of storage space. You need to manually delete these indexes if you no longer need them.
Notice The smaller the disk space, the higher the disk utilization of the Elasticsearch cluster logs and X-Pack monitoring indexes.