---
title: Troubleshoot shard capacity health issues
description: Elasticsearch limits the maximum number of shards to be held per node using the cluster.max_shards_per_node and cluster.max_shards_per_node.frozen settings...
url: https://www.elastic.co/docs/troubleshoot/elasticsearch/troubleshooting-shards-capacity-issues
products:
  - Elasticsearch
applies_to:
  - Elastic Stack: Generally available
---

# Troubleshoot shard capacity health issues
<admonition title="Simplify monitoring with AutoOps">
  AutoOps is a monitoring tool that simplifies cluster management through performance recommendations, resource utilization visibility, and real-time issue detection with resolution paths. Learn more about [AutoOps](https://www.elastic.co/docs/deploy-manage/monitor/autoops).
</admonition>

Elasticsearch limits the maximum number of shards to be held per node using the [`cluster.max_shards_per_node`](https://www.elastic.co/docs/reference/elasticsearch/configuration-reference/miscellaneous-cluster-settings#cluster-max-shards-per-node) and [`cluster.max_shards_per_node.frozen`](https://www.elastic.co/docs/reference/elasticsearch/configuration-reference/miscellaneous-cluster-settings#cluster-max-shards-per-node-frozen) settings. The current shards capacity of the cluster is available in the [health API shards capacity section](https://www.elastic.co/docs/api/doc/elasticsearch/operation/operation-health-report).

## Cluster is close to reaching the configured maximum number of shards for data nodes

The [`cluster.max_shards_per_node`](https://www.elastic.co/docs/reference/elasticsearch/configuration-reference/miscellaneous-cluster-settings#cluster-max-shards-per-node) cluster setting limits the maximum number of open shards for a cluster, only counting data nodes that do not belong to the frozen tier.
This symptom indicates that action should be taken, otherwise, either the creation of new indices or upgrading the cluster could be blocked.
If you're confident your changes won't destabilize the cluster, you can temporarily increase the limit using the [cluster update settings API](https://www.elastic.co/docs/api/doc/elasticsearch/operation/operation-cluster-put-settings).
You can perform the following steps using either [API console](https://www.elastic.co/docs/explore-analyze/query-filter/tools/console), or direct [Elasticsearch API](https://www.elastic.co/docs/reference/elasticsearch/rest-apis) calls.
1. Check the current status of the cluster according the shards capacity indicator:
   ```json
   ```
   The response will look like this:
   ```json
   {
     "cluster_name": "...",
     "indicators": {
       "shards_capacity": {
         "status": "yellow",
         "symptom": "Cluster is close to reaching the configured maximum number of shards for data nodes.",
         "details": {
           "data": {
             "max_shards_in_cluster": 1000, 
             "current_used_shards": 988 
           },
           "frozen": {
             "max_shards_in_cluster": 3000,
             "current_used_shards": 0
           }
         },
         "impacts": [
           ...
         ],
         "diagnosis": [
           ...
       }
     }
   }
   ```
2. Update the [`cluster.max_shards_per_node`](https://www.elastic.co/docs/reference/elasticsearch/configuration-reference/miscellaneous-cluster-settings#cluster-max-shards-per-node) setting with a proper value using the [cluster settings API](https://www.elastic.co/docs/api/doc/elasticsearch/operation/operation-cluster-put-settings):
   ```json

   {
     "persistent" : {
       "cluster.max_shards_per_node": 1200
     }
   }
   ```
   This increase should only be temporary. As a long-term solution, we recommend you add nodes to the oversharded data tier or [reduce your cluster's shard count](/docs/deploy-manage/production-guidance/optimize-performance/size-shards#reduce-cluster-shard-count) on nodes that do not belong to the frozen tier.
3. To verify that the change has fixed the issue, check the current status of the `shards_capacity` indicator:
   ```json
   ```
   The response will look like this:
   ```json
   {
     "cluster_name": "...",
     "indicators": {
       "shards_capacity": {
         "status": "green",
         "symptom": "The cluster has enough room to add new shards.",
         "details": {
           "data": {
             "max_shards_in_cluster": 1000
           },
           "frozen": {
             "max_shards_in_cluster": 3000
           }
         }
       }
     }
   }
   ```
4. When a long-term solution is in place, reset the `cluster.max_shards_per_node` limit:
   ```json

   {
     "persistent" : {
       "cluster.max_shards_per_node": null
     }
   }
   ```


## Cluster is close to reaching the configured maximum number of shards for frozen nodes

The [`cluster.max_shards_per_node.frozen`](https://www.elastic.co/docs/reference/elasticsearch/configuration-reference/miscellaneous-cluster-settings#cluster-max-shards-per-node-frozen) cluster setting limits the maximum number of open shards for a cluster, only counting data nodes that belong to the frozen tier.
This symptom indicates that action should be taken, otherwise, either the creation of new indices or upgrading the cluster could be blocked.
If you're confident your changes won't destabilize the cluster, you can temporarily increase the limit using the [cluster update settings API](https://www.elastic.co/docs/api/doc/elasticsearch/operation/operation-cluster-put-settings).
You can perform the following steps using either [API console](https://www.elastic.co/docs/explore-analyze/query-filter/tools/console), or direct [Elasticsearch API](https://www.elastic.co/docs/reference/elasticsearch/rest-apis) calls.
1. Check the current status of the cluster according the shards capacity indicator:
   ```json
   ```
   The response will look like this:
   ```json
   {
     "cluster_name": "...",
     "indicators": {
       "shards_capacity": {
         "status": "yellow",
         "symptom": "Cluster is close to reaching the configured maximum number of shards for frozen nodes.",
         "details": {
           "data": {
             "max_shards_in_cluster": 1000
           },
           "frozen": {
             "max_shards_in_cluster": 3000, 
             "current_used_shards": 2998 
           }
         },
         "impacts": [
           ...
         ],
         "diagnosis": [
           ...
       }
     }
   }
   ```
2. Update the [`cluster.max_shards_per_node.frozen`](https://www.elastic.co/docs/reference/elasticsearch/configuration-reference/miscellaneous-cluster-settings#cluster-max-shards-per-node-frozen) setting using the [cluster settings API](https://www.elastic.co/docs/api/doc/elasticsearch/operation/operation-cluster-put-settings):
   ```json

   {
     "persistent" : {
       "cluster.max_shards_per_node.frozen": 3200
     }
   }
   ```
   This increase should only be temporary. As a long-term solution, we recommend you add nodes to the oversharded data tier or [reduce your cluster's shard count](/docs/deploy-manage/production-guidance/optimize-performance/size-shards#reduce-cluster-shard-count) on nodes that belong to the frozen tier.
3. To verify that the change has fixed the issue, check the current status of the `shards_capacity` indicator:
   ```json
   ```
   The response will look like this:
   ```json
   {
     "cluster_name": "...",
     "indicators": {
       "shards_capacity": {
         "status": "green",
         "symptom": "The cluster has enough room to add new shards.",
         "details": {
           "data": {
             "max_shards_in_cluster": 1000
           },
           "frozen": {
             "max_shards_in_cluster": 3200
           }
         }
       }
     }
   }
   ```
4. When a long-term solution is in place, reset the `cluster.max_shards_per_node.frozen` limit:
   ```json

   {
     "persistent" : {
       "cluster.max_shards_per_node.frozen": null
     }
   }
   ```