Considerations when changing read/write Capacity Mode - Amazon DynamoDB
Managing capacityManaging auto scaling
Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Considerations when changing read/write Capacity Mode

You can change this setting twice in a 24-hour period, so don’t worry if this needs to be changed in the future. Consider the following when updating your read/write capacity mode in Amazon DynamoDB.

Managing capacity

When you update a table from provisioned to on-demand mode, you don't need to specify how much read and write throughput you expect your application to perform.

Consider the following when you update a table from on-demand to provisioned mode:

  • If you're using the Amazon Web Services Management Console, the console estimates initial provisioned capacity values based on the consumed read and write capacity of your table and global secondary indexes over the past 30 minutes. To override these recommended values, choose Override recommended values.

  • If you're using the Amazon CLI or Amazon SDK, choose the right provisioned capacity settings of your table and global secondary indexes by using Amazon CloudWatch to look at your historical consumption (ConsumedWriteCapacityUnits and ConsumedReadCapacityUnits metrics) to determine the new throughput settings.

    Note

    If you're switching a global table to provisioned mode, look at the maximum consumption across all your regional replicas for base tables and global secondary indexes when determining the new throughput settings.

Managing auto scaling

When you update a table from provisioned to on-demand mode:

  • If you're using the console, all of your auto scaling settings (if any) will be deleted.

  • If you're using the Amazon CLI or Amazon SDK, all of your auto scaling settings will be preserved. These settings can be applied when you update your table to provisioned billing mode again.

When you update a table from on-demand to provisioned mode:

  • If you're using the console, DynamoDB recommends enabling auto scaling with the following defaults:

    • Target utilization: 70%

    • Minimum provisioned capacity: 5 units

    • Maximum provisioned capacity: The Region maximum

  • If you're using the Amazon CLI or SDK, your previous auto scaling settings (if any) are preserved.