Modifying a parameter group - Amazon ElastiCache for Redis

Modifying a parameter group

Important

You cannot modify any default parameter group.

You can modify some parameter values in a parameter group. These parameter values are applied to clusters associated with the parameter group. For more information on when a parameter value change is applied to a parameter group, see Redis-specific parameters.

Modifying a parameter group (Console)

The following procedure shows how to change the cluster-enabled parameter's value using the ElastiCache console. You would use the same procedure to change the value of any parameter.

To change a parameter's value using the ElastiCache console

  1. Sign in to the AWS Management Console and open the ElastiCache console at https://console.aws.amazon.com/elasticache/.

  2. To see a list of all available parameter groups, in the left hand navigation pane choose Parameter Groups.

  3. Choose the parameter group you want to modify by choosing the box to the left of the parameter group's name.

    The parameter group's parameters will be listed at the bottom of the screen. You may need to page through the list to see all the parameters.

  4. To modify one or more parameters, choose Edit Parameters.

  5. Choose Save Changes.

  6. To find the name of the parameter you changed, see Redis-specific parameters. If you have a Redis (cluster mode disabled) cluster and make changes to the following parameters, you must reboot the nodes in the cluster:

    • activerehashing

    • databases

    For more information, see Rebooting nodes.

    Redis (Cluster Mode Enabled) parameter changes

    If you make changes to the following parameters on a Redis (cluster mode enabled) cluster, follow the ensuing steps.

    • activerehashing

    • databases

    1. Create a manual backup of your cluster. See Making manual backups.

    2. Delete the Redis (cluster mode enabled) cluster. See Deleting a cluster.

    3. Restore the cluster using the altered parameter group and backup to seed the new cluster. See Restoring from a backup with optional cluster resizing.

    Changes to other parameters do not require this.

Modifying a parameter group (AWS CLI)

To change a parameter's value using the AWS CLI, use the command modify-cache-parameter-group.

To find the name and permitted values of the parameter you want to change, see Redis-specific parameters

The following sample code sets the value of two parameters, reserved-memory-percent and cluster-enabled on the parameter group myredis32-on-30. We set reserved-memory-percent to 30 (30 percent) and cluster-enabled to yes so that the parameter group can be used with Redis (cluster mode enabled) clusters (replication groups).

For Linux, macOS, or Unix:

aws elasticache modify-cache-parameter-group \ --cache-parameter-group-name myredis32-on-30 \ --parameter-name-values \ ParameterName=reserved-memory-percent,ParameterValue=30 \ ParameterName=cluster-enabled,ParameterValue=yes

For Windows:

aws elasticache modify-cache-parameter-group ^ --cache-parameter-group-name myredis32-on-30 ^ --parameter-name-values ^ ParameterName=reserved-memory-percent,ParameterValue=30 ^ ParameterName=cluster-enabled,ParameterValue=yes

Output from this command will look something like this.

{ "CacheParameterGroupName": "my-redis32-on-30" }

For more information, see modify-cache-parameter-group.

To find the name of the parameter you changed, see Redis-specific parameters.

If you have a Redis (cluster mode disabled) cluster and make changes to the following parameters, you must reboot the nodes in the cluster:

  • activerehashing

  • databases

For more information, see Rebooting nodes.

Redis (Cluster Mode Enabled) parameter changes

If you make changes to the following parameters on a Redis (cluster mode enabled) cluster, follow the ensuing steps.

  • activerehashing

  • databases

  1. Create a manual backup of your cluster. See Making manual backups.

  2. Delete the Redis (cluster mode enabled) cluster. See Deleting a cluster.

  3. Restore the cluster using the altered parameter group and backup to seed the new cluster. See Restoring from a backup with optional cluster resizing.

Changes to other parameters do not require this.

Modifying a parameter group (ElastiCache API)

To change a parameter group's parameter values using the ElastiCache API, use the ModifyCacheParameterGroup action.

To find the name and permitted values of the parameter you want to change, see Redis-specific parameters

The following sample code sets the value of two parameters, reserved-memory-percent and cluster-enabled on the parameter group myredis32-on-30. We set reserved-memory-percent to 30 (30 percent) and cluster-enabled to yes so that the parameter group can be used with Redis (cluster mode enabled) clusters (replication groups).

https://elasticache.us-west-2.amazonaws.com/ ?Action=ModifyCacheParameterGroup &CacheParameterGroupName=myredis32-on-30 &ParameterNameValues.member.1.ParameterName=reserved-memory-percent &ParameterNameValues.member.1.ParameterValue=30 &ParameterNameValues.member.2.ParameterName=cluster-enabled &ParameterNameValues.member.2.ParameterValue=yes &SignatureVersion=4 &SignatureMethod=HmacSHA256 &Timestamp=20150202T192317Z &Version=2015-02-02 &X-Amz-Credential=<credential>

For more information, see ModifyCacheParameterGroup.

If you have a Redis (cluster mode disabled) cluster and make changes to the following parameters, you must reboot the nodes in the cluster:

  • activerehashing

  • databases

For more information, see Rebooting nodes.

Redis (Cluster Mode Enabled) parameter changes

If you make changes to the following parameters on a Redis (cluster mode enabled) cluster, follow the ensuing steps.

  • activerehashing

  • databases

  1. Create a manual backup of your cluster. See Making manual backups.

  2. Delete the Redis (cluster mode enabled) cluster. See Deleting a cluster.

  3. Restore the cluster using the altered parameter group and backup to seed the new cluster. See Restoring from a backup with optional cluster resizing.

Changes to other parameters do not require this.