---
name: databases-for-redis-howto-config
title: Changing the Redis configuration
description: In IBM Cloud® Databases for Redis, you can change some of the Redis configuration settings to tune your databases to your use-case. In a typical Redis setting, you can change the configuration from the command line by using `CONFIG SET`. You can still use `CONFIG SET` on your deployment but the changes do NOT persist if there is a failover, node restart, or other event on your deployment. Changing the configuration with `CONFIG SET` can be used for testing, evaluation, and tuning purposes.
last-updated: 2025-10-13
---

> ## Documentation Index
> The table of contents for this documentation set is at https://cloud.ibm.com/docs/databases-for-redis?format=markdown
> The index for all IBM Cloud docs is at: https://cloud.ibm.com/docs/llms.txt
> Use these files to discover more information as needed.

# Changing the Redis configuration
{: #changing-configuration}

In IBM Cloud® Databases for Redis, you can change some of the Redis configuration settings to tune your databases to your use-case. In a typical Redis setting, you can change the configuration from the command line by using [`CONFIG SET`](https://redis.io/commands/config-set){: external}. You can still use `CONFIG SET` on your deployment but the changes do NOT persist if there is a failover, node restart, or other event on your deployment. Changing the configuration with `CONFIG SET` can be used for testing, evaluation, and tuning purposes.

In Redis 6 and above versions, only `CONFIG GET` and `CONFIG RESETSTAT` are exposed.
{: note}

To make permanent changes to the database configuration, use the Cloud Databases [CLI plug-in](https://cloud.ibm.com/docs/databases-cli-plugin?topic=databases-cli-plugin-cdb-reference&format=markdown#deployment-configuration) or [API](https://cloud.ibm.com/apidocs/cloud-databases-api/cloud-databases-api-v5#updatedatabaseconfiguration) to write the changes to the configuration file for your deployment. 

To make a change, you send a JSON object with the settings that you want to change and their new values. For example, to set the `maxmemory-policy` setting, you would supply the following either to the CLI or to the API.

```sh
{"configuration":{"maxmemory-policy":"allkeys-lru"}}
```
{: .pre}

## Using the CLI
{: #using-cli}
{: cli}

View the configuration schema of possible settings through the Cloud Databases cli-plugin with the [`cdb deployment-configuration-schema`](https://cloud.ibm.com/docs/databases-cli-plugin?topic=databases-cli-plugin-cdb-reference&format=markdown#deployment-configuration-schema) command.

```sh
ibmcloud cdb deployment-configuration-schema <INSTANCE_NAME_OR_CRN>
```
{: .pre}

To change your configuration, use the [`cdb deployment-configuration`](https://cloud.ibm.com/docs/databases-cli-plugin?topic=databases-cli-plugin-cdb-reference&format=markdown#deployment-configuration) command.

```sh
ibmcloud cdb deployment-configuration <INSTANCE_NAME_OR_CRN> [@JSON_FILE | JSON_STRING]
```
{: .pre}

The command reads the changes that you would like to make from the JSON object or a file.

## Using the API
{: #using-api}
{: api}

There are two deployment-configuration endpoints, one for viewing the configuration schema and one for changing the configuration. To view the configuration schema, send a `GET` request to `/deployments/{id}/configuration/schema`.

To change the configuration, send the settings that you would like to change as a JSON object in the request body of a `PATCH` request to `/deployments/{id}/configuration`.

For more information, see the [API reference](https://cloud.ibm.com/apidocs/cloud-databases-api/cloud-databases-api-v5#updatedatabaseconfiguration).

## Available configuration settings
{: # config-settings}

To check the current value of a setting, use [`CONFIG GET`](https://redis.io/commands/config-get){: external} from a [CLI client](https://cloud.ibm.com/docs/databases-for-redis?topic=databases-for-redis-connecting-cli-client&format=markdown). You can check all of the settings by using `CONFIG GET *`.

Many of the settings are used to configure Redis as a cache. For more information, see the [Configuring Redis as a Cache](https://cloud.ibm.com/docs/databases-for-redis?topic=databases-for-redis-redis-cache&format=markdown) page.

| Setting | Default | Notes | 
| ---------- | ----- | ----------- | 
| [`maxmemory`](https://redis.io/topics/memory-optimization#memory-allocation) | 80% of your deployment's memory | Determines the amount of data that you can store in Redis. | 
| [`appendonly`](https://redis.io/topics/persistence#append-only-file)| `yes` | Enables or disables Redis persistence. | 
| [`maxmemory-policy`](https://redis.io/topics/lru-cache#eviction-policies) |`noeviction` | Determines eviction behavior when `maxmemory` limit is reached. | 
| [`maxmemory-samples`](https://redis.io/topics/lru-cache#approximated-lru-algorithm) | `5`| Tunes LRU eviction algorithm when Redis is configured as a cache. | 
| `stop-writes-on-bgsave-error` | `yes` | Redis stops accepting writes if it detects an unsuccessful backup snapshot.  | 
{: caption="Configuration Settings for Redis" caption-side="top"}