Amazon ElastiCache Serverless for Valkey now offers zero-downtime online migration from self-managed Valkey and Redis OSS on EC2. This feature allows applications to continue reading and writing data throughout the migration process without errors. The migration occurs in three phases: preparation, data synchronization, and cutover. During preparation, users receive a migration endpoint for their application. Data synchronization replicates continuously from the source to the serverless cache. Cutover can be manual or automatic once data is synchronized. The migration process utilizes TLS encryption and authentication, storing credentials in AWS Secrets Manager for security. It supports self-managed Redis OSS from version 4.0 to 7.2 and Valkey from 7.2 to 8.1, migrating to Valkey 9.0. Migration usage is free for the initial 180 days per AWS account. Following the free period, node-hour charges apply for migration nodes. The ElastiCache Serverless cache is billed separately at standard rates. This online migration capability is available across all commercial, China, and AWS GovCloud Regions. To begin, create or select an empty ElastiCache Serverless cache and initiate the migration via the console or CLI.