SplitShard

Splits a shard into two new shards in the Kinesis data stream, to increase the stream's capacity to ingest and transport data. SplitShard is called when there is a need to increase the overall capacity of a stream because of an expected increase in the volume of data records being ingested. This API is only supported for the data streams with the provisioned capacity mode.

You can also use SplitShard when a shard appears to be approaching its maximum utilization; for example, the producers sending data into the specific shard are suddenly sending more than previously anticipated. You can also call SplitShard to increase stream capacity, so that more Kinesis Data Streams applications can simultaneously read data from the stream for real-time processing.

You must specify the shard to be split and the new hash key, which is the position in the shard where the shard gets split in two. In many cases, the new hash key might be the average of the beginning and ending hash key, but it can be any hash key value in the range being mapped into the shard. For more information, see Split a Shard in the Amazon Kinesis Data Streams Developer Guide.

You can use DescribeStreamSummary and the ListShards APIs to determine the shard ID and hash key values for the ShardToSplit and NewStartingHashKey parameters that are specified in the SplitShard request.

SplitShard is an asynchronous operation. Upon receiving a SplitShard request, Kinesis Data Streams immediately returns a response and sets the stream status to UPDATING. After the operation is completed, Kinesis Data Streams sets the stream status to ACTIVE. Read and write operations continue to work while the stream is in the UPDATING state.

You can use DescribeStreamSummary to check the status of the stream, which is returned in StreamStatus. If the stream is in the ACTIVE state, you can call SplitShard.

If the specified stream does not exist, DescribeStreamSummary returns a ResourceNotFoundException. If you try to create more shards than are authorized for your account, you receive a LimitExceededException.

For the default shard limit for an AWS account, see Kinesis Data Streams Limits in the Amazon Kinesis Data Streams Developer Guide. To increase this limit, contact AWS Support.

If you try to operate on too many streams simultaneously using CreateStream, DeleteStream, MergeShards, and/or SplitShard, you receive a LimitExceededException.

SplitShard has a limit of five transactions per second per account.

Request Syntax

{
   "NewStartingHashKey": "string",
   "ShardToSplit": "string",
   "StreamARN": "string",
   "StreamName": "string"
}

Request Parameters

The request accepts the following data in JSON format.

Response Elements

If the action is successful, the service sends back an HTTP 200 response with an empty HTTP body.

Errors

For information about the errors that are common to all actions, see Common Errors.

Examples

To split a shard

The following JSON example splits the specified shard.

Sample Request

POST / HTTP/1.1
Host: kinesis.<region>.<domain>
Content-Length: <PayloadSizeBytes>
User-Agent: <UserAgentString>
Content-Type: application/x-amz-json-1.1
Authorization: <AuthParams>
Connection: Keep-Alive 
X-Amz-Date: <Date>
X-Amz-Target: Kinesis_20131202.SplitShard
{
  "StreamName": "exampleStreamName",
  "ShardToSplit": "shardId-000000000000",
  "NewStartingHashKey": "10"
}

Sample Response

HTTP/1.1 200 OK
x-amzn-RequestId: <RequestId>
Content-Type: application/x-amz-json-1.1
Content-Length: <PayloadSizeBytes>
Date: <Date>

See Also

For more information about using this API in one of the language-specific AWS SDKs, see the following: