Creating an Amazon ElastiCache cluster using Amazon RDS DB instance settings

ElastiCache is a fully managed, in-memory caching service that provides microsecond read and write latencies that support flexible, real-time use cases. ElastiCache can help you accelerate application and database performance. You can use ElastiCache as a primary data store for use cases that don't require data durability, such as gaming leaderboards, streaming, and data analytics. ElastiCache helps remove the complexity associated with deploying and managing a distributed computing environment. For more information, see Common ElastiCache Use Cases and How ElastiCache Can Help for Memcached and Common ElastiCache Use Cases and How ElastiCache Can Help for Redis. You can use the Amazon RDS console for creating ElastiCache clusters.

Amazon ElastiCache works with both the Redis and Memcached engines. If you're unsure which engine you want to use, see Comparing Memcached and Redis. For more information about Amazon ElastiCache, see the Amazon ElastiCache User Guide.

Overview of ElastiCache cluster creation with RDS DB instance settings

You can create an ElastiCache cluster from Amazon RDS using the same configuration settings as a newly created or existing RDS DB instance.

Some use-cases to associate an ElastiCache cluster with your DB instance:

• You can save costs and improve your performance by using ElastiCache with RDS versus running on RDS alone.

  For example, you can save up to 55% in cost and gain up to 80x faster read performance by using ElastiCache with RDS for MySQL versus RDS for MySQL alone.

• You can use the ElastiCache cluster as a primary data store for applications that don't require data durability. Your applications that use Redis or Memcached can use ElastiCache with almost no modification.

When you create an ElastiCache cluster from RDS, the ElastiCache cluster inherits the following settings from the associated RDS DB instance:

• ElastiCache connectivity settings

• ElastiCache security settings

You can also set the cluster configuration settings according to your requirements.

Setting up ElastiCache in your applications

Your applications must be set up to utilize ElastiCache clusters. You can also optimize and improve cluster performance by setting up your applications to use caching strategies depending on your requirements.

• To access your ElastiCache cluster and get started, see Getting started with Amazon ElastiCache for Redis and Getting started with Amazon ElastiCache for Memcached.

• For more information about caching strategies, see Caching strategies and best practices for Memcached and Caching strategies and best practices for Redis.

• For more information about high availability in ElastiCache for Redis clusters, see High availability using replication groups.

• You might incur costs associated with backup storage, data transfer within or across regions, or use of AWS Outposts. For pricing details, see Amazon ElastiCache pricing.

Creating an ElastiCache cluster with settings from a new RDS DB instance

After creating a new RDS DB instance in the RDS console, you can create add-ons for your RDS DB instance from the Suggested add-ons window.

In the Suggested add-ons window, you can create an ElastiCache cluster from RDS with the same settings as your newly created RDS DB instance.

Create an ElastiCache cluster with settings from a new DB instance

1. To create a DB instance, follow the instructions in Creating an Amazon RDS DB instance.

2. After creating a new RDS DB instance, the console displays the Suggested add-ons window. Select Create an ElastiCache cluster from RDS using your DB settings.

   In the ElastiCache configuration section, the Source DB identifier displays which DB instance the ElastiCache cluster inherits settings from.

3. Choose whether you want to create a Redis or Memcached cluster. For more information, see Comparing Memcached and Redis.

   If you choose Redis cluster, then choose whether you want to keep the cluster mode Enabled or Disabled. For more information, see Replication: Redis (Cluster Mode Disabled) vs. Redis (Cluster Mode Enabled).

   

4. Enter values for Name, Description, and Engine version.

   For Engine version, the recommended default value is the latest engine version. You can also choose an Engine version for the ElastiCache cluster that best meets your requirements.

5. Choose the node type in the Node type option. For more information, see Managing nodes.

   If you choose to create a Redis cluster with the Cluster mode set to Enabled, then enter the number of shards (partitions/node groups) in the Number of shards option.

   Enter the number of replicas of each shard in Number of replicas.

   Note

   The selected node type, the number of shards, and the number of replicas all affect your cluster performance and resource costs. Be sure these settings match your database needs. For pricing information, see Amazon ElastiCache pricing.

6. Confirm the ElastiCache connectivity settings.

   RDS automatically fills the Port and the Network type. ElastiCache creates an equivalent Subnet group from the source database. To customize these settings, select Customize your connectivity settings.

   

7. Confirm the ElastiCache security settings.

   ElastiCache provides the default values for Encryption at rest, Encryption key, Encryption in transit, Access control, and Security groups. To customize these settings, select Customize your security settings.

   

8. Verify the default and inherited settings of your ElastiCache cluster. Some settings can't be changed after creation.

   Note

   RDS might adjust the backup window of your ElastiCache cluster to meet the minimum window requirement of 60 minutes. The backup window of your source database remains the same.

9. When you're ready, choose Create ElastiCache cluster.

The console displays a confirmation banner for the ElastiCache cluster creation. Follow the link in the banner to the ElastiCache console to view the cluster details. The ElastiCache console displays the newly created ElastiCache cluster.

Creating an ElastiCache cluster with settings from an existing RDS DB instance

You can create an ElastiCache cluster for your existing RDS DB instances from the Actions dropdown menu in the console.

Create an ElastiCache cluster with settings from an existing DB instance

1. In the Databases page, select the required DB instance.

2. In the Actions dropdown menu, choose Create ElastiCache cluster to create an ElastiCache cluster in RDS that has the same settings as your existing RDS DB instance.

   In the ElastiCache configuration section, the Source DB identifier shows which DB instance the ElastiCache cluster inherits settings from.

3. Choose whether you want to create a Redis or Memcached cluster. For more information, see Comparing Memcached and Redis.

   If you choose Redis cluster, then choose whether you want to keep the cluster mode Enabled or Disabled. For more information, see Replication: Redis (Cluster Mode Disabled) vs. Redis (Cluster Mode Enabled).

   

4. Enter values for Name, Description, and Engine version.

   For Engine version, the recommended default value is the latest engine version. You can also choose an Engine version for the ElastiCache cluster that best meets your requirements.

5. Choose the node type in the Node type option. For more information, see Managing nodes.

   If you choose to create a Redis cluster with the Cluster mode set to Enabled, then enter the number of shards (partitions/node groups) in the Number of shards option.

   Enter the number of replicas of each shard in Number of replicas.

   Note

   The selected node type, the number of shards, and the number of replicas all affect your cluster performance and resource costs. Be sure these settings match your database needs. For pricing information, see Amazon ElastiCache pricing.

6. Confirm the ElastiCache connectivity settings.

   RDS automatically fills the Port and the Network type. ElastiCache creates an equivalent Subnet group from the source database. To customize these settings, select Customize your connectivity settings.

   

7. Confirm the ElastiCache security settings.

   ElastiCache provides the default values for Encryption at rest, Encryption key, Encryption in transit, Access control, and Security groups. To customize these settings, select Customize your security settings.

   

8. Verify the default and inherited settings of your ElastiCache cluster. Some settings can't be changed after creation.

   Note

   RDS might adjust the backup window of your ElastiCache cluster to meet the minimum window requirement of 60 minutes. The backup window of your source database remains the same.

9. When you're ready, choose Create ElastiCache cluster.

The console displays a confirmation banner for the ElastiCache cluster creation. Follow the link in the banner to the ElastiCache console to view the cluster details. The ElastiCache console displays the newly created ElastiCache cluster.