Help Center/ Cloud Search Service/ User Guide/ Using Elasticsearch for Data Search/ Managing Index Policies for an Elasticsearch Cluster/ Decoupling Index Storage and Compute in an Elasticsearch Cluster Through Index Lifecycle Management
Updated on 2025-09-05 GMT+08:00

Decoupling Index Storage and Compute in an Elasticsearch Cluster Through Index Lifecycle Management

Overview

CSS supports decoupled storage and compute. That is, indexes can be frozen and their data can be dumped to OBS to reduce the storage cost of cold data. This document describes how to use index lifecycle management to automatically freeze indexes at a specific time to decouple storage and compute.

In this example, a lifecycle policy is created for an Elasticsearch 7.10.2 cluster. According to this policy, a newly created index is automatically frozen in three days, with data dumped to OBS; and deleted in seven days.

Figure 1 Storage-compute decoupling

Constraints

Only Elasticsearch 7.6.2 and 7.10.2 clusters support decoupled storage and compute.

Prerequisites

The Elasticsearch cluster is available.

Decoupling Index Storage and Compute Through Index Lifecycle Management

  1. Log in to Kibana.
    1. Log in to the CSS management console.
    2. In the navigation pane on the left, choose Clusters > Elasticsearch.
    3. In the cluster list, find the target cluster, and click Kibana in the Operation column to log in to the Kibana console.
    4. In the left navigation pane, choose Dev Tools.
  2. Create a lifecycle policy named hot_warm_policy.

    Policy description: Three days after an index is created, the API for freezing indexes is automatically called to dump data to OBS. Seven days after index creation, the index is deleted.

    PUT _opendistro/_ism/policies/hot_warm_policy
    {
      "policy": {
        "description": "hot warm archive delete workflow",
        "error_notification": null,
        "default_state": "hot",
        "states": [
          {
            "name": "hot",
            "actions": [],
            "transitions": [
              {
                "state_name": "warm",
                "conditions": {
                  "min_index_age": "3d"
                }
              }
            ]
          },
          {
            "name": "warm",
            "actions": [
              {
                "freeze_low_cost": {}
              }
            ],
            "transitions": [
              {
                "state_name": "delete",
                "conditions": {
                  "min_index_age": "7d"
                }
              }
            ]
          },
          {
            "name": "delete",
            "actions": [
              {
                "delete": {}
              }
            ],
            "transitions": []
          }
        ]
      }
    }
  3. Create the index template template_hot_warm.

    Template description: All the new indexes starting with data are automatically associated with the lifecycle policy hot_warm_policy.

    PUT _template/template_hot_warm
    {
      "index_patterns": "data*",
      "settings": {
        "number_of_replicas": 5,
        "number_of_shards": 1,
        "opendistro.index_state_management.policy_id": "hot_warm_policy"
      },
      "mappings": {
        "properties": {
          "name": {
            "type": "text"
          }
        }
      }
    }
    Table 1 Parameter description

    Parameter

    Description

    number_of_shards

    Number of index shards

    number_of_replicas

    Number of index shard replicas

    opendistro.index_state_management.policy_id

    Lifecycle policy name

  4. Create the data-2022-06-06 index. The index automatically uses the template_hot_warm template and associates the index template with the lifecycle policy hot_warm_policy. As such, the index is automatically frozen in three days, and deleted in seven days after creation.
    POST data-2022-06-06/_bulk
    {"index":{}}
    {"name":"name1"}
    {"index":{}}
    {"name":"name2"}
    {"index":{}}
    {"name":"name3"}
    {"index":{}}
    {"name":"name4"}
    {"index":{}}
    {"name":"name5"}
    {"index":{}}
    {"name":"name6"}
  5. Query data and check whether storage and compute is automatically decoupled.
    • Three days after the index is created, check the frozen index.
      GET _cat/freeze_indices?s=i&v

      The index generated three days ago is expected to be frozen.

      health status index                  uuid                   pri rep docs.count docs.deleted store.size pri.store.size
      green  open   data-2022-06-06  x8ab5NX6T3Ox_xoGUanogQ    1   1          6            0      7.6kb          3.8kb
    • Seven days after index creation, check the index. The index is expected to be deleted.