You can now scale up your existing ElastiCache for Redis clusters to a larger node type with a few clicks. Simply modify your node type by choosing from the available options and let ElastiCache manage the rest. Your existing node endpoints will persist,thus no application update is required. Scale up for Redis is designed to obtain a best effort to retain your existing data and requires Redis replication to succeed. For more details, please refer to Jeff Barr’s blog and ElastiCache Documentation.
Source: amazon.com