Updates the shard count of the specified stream to the specified number of shards.
Updating the shard count is an asynchronous operation. Upon receiving the request, Kinesis Data Streams returns immediately and sets the status of the stream to
. After the update is complete, Kinesis Data Streams sets the status of the stream back to
. Depending on the size of the stream, the scaling action could take a few minutes to complete. You can continue to read and write data to your stream while its status is
To update the shard count, Kinesis Data Streams performs splits or merges on individual shards. This can cause short-lived shards to be created, in addition to the final shards. These short-lived shards count towards your total shard limit for your account in the Region.
When using this operation, we recommend that you specify a target shard count that is a multiple of 25% (25%, 50%, 75%, 100%). You can specify any target value within your shard limit. However, if you specify a target that isn't a multiple of 25%, the scaling action might take longer to complete.
This operation has the following default limits. By default, you cannot do the following:
- Scale more than ten times per rolling 24-hour period per stream
- Scale up to more than double your current shard count for a stream
- Scale down below half your current shard count for a stream
- Scale up to more than 10000 shards in a stream
- Scale a stream with more than 10000 shards down unless the result is less than 10000 shards
- Scale up to more than the shard limit for your account
For the default limits for an Amazon Web Services account, see Streams Limits
in the Amazon Kinesis Data Streams Developer Guide
. To request an increase in the call rate limit, the shard limit for this API, or your overall shard limit, use the limits form