---
title: Troubleshoot node bootlooping
description: When you try to apply a configuration change to a deployment, an error might appear and resources might not restart. This can result in bootlooping, where...
url: https://www.elastic.co/docs/troubleshoot/monitoring/node-bootlooping
products:
  - Elastic Cloud Enterprise
  - Elastic Cloud Hosted
  - Elastic Cloud on Kubernetes
applies_to:
  - Elastic Cloud Hosted: Generally available
  - Elastic Cloud on Kubernetes: Generally available
  - Elastic Cloud Enterprise: Generally available
---

# Troubleshoot node bootlooping
When you try to apply a configuration change to a deployment, an error might appear and resources might not restart. This can result in _bootlooping_, where the deployment resources cycle through a continual reboot process.
- In Elastic Cloud Hosted and Elastic Cloud Enterprise, a deployment health warning appears:
  ![A screen capture of the deployment page showing an error: Latest change to Elasticsearch configuration failed.](https://www.elastic.co/docs/troubleshoot/images/cloud-ec-ce-configuration-change-failure.png)
  To confirm if your Elasticsearch cluster is bootlooping, you can check the most recent plan under your [Deployment Activity page](https://www.elastic.co/docs/deploy-manage/deploy/elastic-cloud/keep-track-of-deployment-activity) for the error:
  ```sh
  Plan change failed: Some instances were unable to start properly.
  ```
- In Elastic Cloud on Kubernetes, a `CrashLoopBackOff` pod state occurs.

To help diagnose these and any other types of issues in your deployments, we recommend [setting up monitoring](https://www.elastic.co/docs/deploy-manage/monitor). Then, you can easily view your deployment health and access log files to troubleshoot this configuration failure.
If this occurs, correlating product logs should report `fatal exception while booting`. For example, Elasticsearch will report:
```sh
fatal exception while booting Elasticsearch
```

If you can't determine the root cause, you can try to reset the deployment to the latest successful configuration:
- For Elastic Cloud Hosted and Elastic Cloud Enterprise, select **Edit** on the deployment page, then **Save** without making any changes.
- For Elastic Cloud on Kubernetes, use [`kubectl apply`](https://kubernetes.io/docs/reference/kubectl/generated/kubectl_apply/) to reset.

Following are some frequent causes of a failed configuration change:
1. [Secure settings](#ec-config-change-errors-secure-settings)
2. [Expired custom plugins or bundles](#ec-config-change-errors-expired-bundle-extension)
3. [OOM errors](#ec-config-change-errors-oom-errors)
4. [Existing index](#ec-config-change-errors-existing-index)
5. [Insufficient Storage](#ec-config-change-errors-insufficient-storage)

For an example, watch this [video walkthrough](https://www.youtube.com/watch?v=8MnXZ9egBbQ).
<admonition title="Simplify monitoring with AutoOps">
  AutoOps is a [monitoring](https://www.elastic.co/docs/deploy-manage/monitor) 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>


## Secure settings

The most frequent cause of a failed deployment configuration change is due to invalid or mislocated [secure settings](https://www.elastic.co/docs/deploy-manage/security/secure-settings). This can frequently be discovered by searching Elasticsearch logs for one of the following error messages:
```sh
# Typical Error Message
#------------------------------
[ERROR][org.elasticsearch.bootstrap.Elasticsearch] ... fatal exception while booting Elasticsearch
IllegalStateException: security initialization failed

java.lang.IllegalArgumentException: unknown secure setting

org.elasticsearch.common.settings.SettingsException:
The configuration setting [xpack.security.authc.realms.foobar.foobar1.foobar2.client_secret] is required
#------------------------------
```

These are settings typically added to the keystore for the purpose of:
1. Setting up third-party authentication, for example [SAML](https://www.elastic.co/docs/deploy-manage/users-roles/cluster-or-deployment-auth/saml), [OpenID Connect](https://www.elastic.co/docs/deploy-manage/users-roles/cluster-or-deployment-auth/openid-connect), or [Kerberos](https://www.elastic.co/docs/deploy-manage/users-roles/cluster-or-deployment-auth/kerberos).
2. Setting up a [custom repository](https://www.elastic.co/docs/deploy-manage/tools/snapshot-and-restore/elastic-cloud-hosted).

The keystore allows you to safely store sensitive settings, such as passwords, as a key/value pair. You can then access a secret value from a settings file by referencing its key. Importantly, not all settings can be stored in the keystore, and the keystore does not validate the settings that you add. Adding unsupported settings can cause Elasticsearch or other components to fail to restart. To check whether a setting is supported in the keystore, look for a "Secure" qualifier in the [lists of reloadable settings](https://www.elastic.co/docs/deploy-manage/security/secure-settings). Additionally, some settings require their correlating settings to also be configured at the same time to take effect and the missing setting will induce fatal errors like:
```sh
The configuration setting [...] is required
```

The following sections detail some secure settings problems that can result in a configuration change error that can prevent a deployment from restarting. You might diagnose these plan failures via the logs or via their [related exit codes](/docs/deploy-manage/maintenance/start-stop-services/start-stop-elasticsearch#fatal-errors) `1`, `3`, and `78`.
<tip>
  If you configure these settings via a client tool, such as the [Terraform Provider for Elastic Cloud](https://github.com/elastic/terraform-provider-ec), or through an API and encounter the error, try configuring the settings directly in the Cloud UI to isolate the cause. If configuring in the Cloud UI does not result in the same error, it suggests that the keystore setting is valid, and the method of configuration should be examined. Conversely, if the same error is reported, it suggests that the keystore setting may be invalid and should be reviewed.
</tip>


### Invalid or outdated values

The keystore does not validate any settings that you add, so invalid or outdated values are a common source of errors when you apply a configuration change to a deployment.
To check the current set of stored settings:
- For Elastic Cloud Hosted or Elastic Cloud Enterprise:
  1. Open the deployment **Security** page.
2. In the **Elasticsearch keystore** section, check the **Security keys** list. The list is shown only if you currently have settings configured in the keystore.
- For Elastic Cloud on Kubernetes, check your [secure settings](https://www.elastic.co/docs/deploy-manage/security/k8s-secure-settings).

One frequent cause of errors is when settings in the keystore are no longer valid, such as when SAML settings are added for a test environment, but the settings are either not carried over or no longer valid in a production environment.

### Snapshot repositories

Sometimes, settings added to the keystore to connect to a snapshot repository may not be valid. When this happens, you may get an error such as
```sh
SettingsException[Neither a secret key nor a shared access token was set.]
```

For example, when adding an [Azure repository storage setting](/docs/deploy-manage/tools/snapshot-and-restore/azure-repository#repository-azure-usage) such as `azure.client.default.account` to the keystore, the associated setting `azure.client.default.key` must also be added for the configuration to be valid.

### Third-party authentication

When you configure third-party authentication, it’s important that all required configuration elements that are stored in the keystore are included in the Elasticsearch user settings file. For example, when you [create a SAML realm](/docs/deploy-manage/users-roles/cluster-or-deployment-auth/saml#saml-create-realm), omitting a field such as `idp.entity_id` when that setting is present in the keystore results in a failed configuration change.

### Wrong location

In some cases, settings may accidentally be added to the keystore that should have been added to the [Elasticsearch user settings file](https://www.elastic.co/docs/deploy-manage/deploy/elastic-cloud/edit-stack-settings). It’s always a good idea to check the [lists of reloadable settings](https://www.elastic.co/docs/deploy-manage/security/secure-settings) to determine if a setting can be stored in the keystore. Settings that can safely be added to the keystore are flagged as `Secure`.

## Expired custom plugins or bundles

<applies-to>
  - Elastic Cloud Hosted: Generally available
  - Elastic Cloud Enterprise: Generally available
</applies-to>

During the process of applying a configuration change, Elastic Cloud checks to determine if any [uploaded custom plugins or bundles](https://www.elastic.co/docs/deploy-manage/deploy/elastic-cloud/upload-custom-plugins-bundles) are expired.
Problematic plugins produce oscillating Elasticsearch start-up logs like the following:
```sh
Booting at Sun Sep 4 03:06:43 UTC 2022
Installing user plugins.
Installing elasticsearch-analysis-izumo-master-7.10.2-20210618-28f8a97...
/app/elasticsearch.sh: line 169: [: too many arguments
Booting at Sun Sep 4 03:06:58 UTC 2022
Installing user plugins.
Installing elasticsearch-analysis-izumo-master-7.10.2-20210618-28f8a97...
/app/elasticsearch.sh: line 169: [: too many arguments
```

Problematic bundles produce similar oscillations but their install log would appear like
```sh
2024-11-17 15:18:02   https://found-user-plugins.s3.amazonaws.com/XXXXX/XXXXX.zip?response-content-disposition=attachment%3Bfilename%XXXXX%2F4007535947.zip&x-elastic-extension-version=1574194077471&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20241016T133214Z&X-Amz-SignedHeaders=host&X-Amz-Expires=86400&XAmz-Credential=XXXXX%2F20201016%2Fus-east-1%2Fs3%2Faws4_request&X-AmzSignature=XXXXX
```

Noting in example that the bundle’s expiration `X-Amz-Date=20241016T133214Z` is before than the log timestamp `2024-11-17 15:18:02` so this bundle is considered expired.
To view any added plugins or bundles:
1. For Elastic Cloud Hosted, from your deployment's navigation menu, select **Extensions**. For Elastic Cloud Enterprise, go to the **Features** page and open the **Extensions** tab.
2. Select any extension and then choose **Update extension** to renew it. No other changes are needed, and any associated configuration change failures should now be able to succeed.


## OOM errors

Configuration change errors can occur when there is insufficient RAM configured for a data tier. In this case, the cluster typically also shows OOM (out of memory) errors. To resolve these, you need to increase the amount of heap memory. For instances up to 64 GB of RAM, heap memory is half of the total memory allocated. For instances larger than 64 GB, the heap size is capped at 32 GB. You might also detect OOM in plan changes via their [related exit codes](/docs/deploy-manage/maintenance/start-stop-services/start-stop-elasticsearch#fatal-errors) `127`, `137`, and `158`.
Refer to the [High JVM memory pressure](https://www.elastic.co/docs/troubleshoot/elasticsearch/high-jvm-memory-pressure) documentation for more troubleshooting guidance.
You can also read our detailed blog [Managing and troubleshooting Elasticsearch memory](https://www.elastic.co/blog/managing-and-troubleshooting-elasticsearch-memory).

## Existing index

In rare cases, when you attempt to upgrade the version of a deployment and the upgrade fails on the first attempt, subsequent attempts to upgrade may fail due to already existing resources. The problem may be due to the system preventing itself from overwriting existing indices, resulting in an error such as this:
```sh
Another Kibana instance appears to be migrating the index. Waiting for that migration to complete. If no other Kibana instance is attempting migrations, you can get past this message by deleting index .kibana_2 and restarting Kibana
```

To resolve this:
1. Check that you don’t need the content.
2. Run an Elasticsearch [Delete index request](https://www.elastic.co/docs/api/doc/elasticsearch/operation/operation-indices-delete) to remove the existing index.
   In this example, the `.kibana_2` index is the rollover of saved objects (such as Kibana visualizations or dashboards) from the original `.kibana_1` index. Since `.kibana_2` was created as part of the failed upgrade process, this index does not yet contain any pertinent data and it can safely be deleted.
3. Retry the deployment configuration change.


## Insufficient storage

Configuration change errors can occur when there is insufficient disk space for a data tier. To resolve this, you need to increase the size of that tier to ensure it provides enough storage to accommodate the data in your cluster tier considering the [high watermark](https://www.elastic.co/docs/reference/elasticsearch/configuration-reference/cluster-level-shard-allocation-routing-settings#disk-based-shard-allocation). For troubleshooting walkthrough, see [Fix watermark errors](https://www.elastic.co/docs/troubleshoot/elasticsearch/fix-watermark-errors).