AWS SDK Version 3 for .NET
API Reference

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Gets data records from an Amazon Kinesis stream's shard.

Specify a shard iterator using the ShardIterator parameter. The shard iterator specifies the position in the shard from which you want to start reading data records sequentially. If there are no records available in the portion of the shard that the iterator points to, GetRecords returns an empty list. Note that it might take multiple calls to get to a portion of the shard that contains records.

You can scale by provisioning multiple shards per stream while considering service limits (for more information, see Streams Limits in the Amazon Kinesis Streams Developer Guide). Your application should have one thread per shard, each reading continuously from its stream. To read from a stream continually, call GetRecords in a loop. Use GetShardIterator to get the shard iterator to specify in the first GetRecords call. GetRecords returns a new shard iterator in NextShardIterator. Specify the shard iterator returned in NextShardIterator in subsequent calls to GetRecords. Note that if the shard has been closed, the shard iterator can't return more data and GetRecords returns null in NextShardIterator. You can terminate the loop when the shard is closed, or when the shard iterator reaches the record with the sequence number or other attribute that marks it as the last record to process.

Each data record can be up to 1 MB in size, and each shard can read up to 2 MB per second. You can ensure that your calls don't exceed the maximum supported size or throughput by using the Limit parameter to specify the maximum number of records that GetRecords can return. Consider your average record size when determining this limit.

The size of the data returned by GetRecords varies depending on the utilization of the shard. The maximum size of data that GetRecords can return is 10 MB. If a call returns this amount of data, subsequent calls made within the next 5 seconds throw ProvisionedThroughputExceededException. If there is insufficient provisioned throughput on the shard, subsequent calls made within the next 1 second throw ProvisionedThroughputExceededException. Note that GetRecords won't return any data when it throws an exception. For this reason, we recommend that you wait one second between calls to GetRecords; however, it's possible that the application will get exceptions for longer than 1 second.

To detect whether the application is falling behind in processing, you can use the MillisBehindLatest response attribute. You can also monitor the stream using CloudWatch metrics and other mechanisms (see Monitoring in the Amazon Kinesis Streams Developer Guide).

Each Amazon Kinesis record includes a value, ApproximateArrivalTimestamp, that is set when a stream successfully receives and stores a record. This is commonly referred to as a server-side timestamp, whereas a client-side timestamp is set when a data producer creates or sends the record to a stream (a data producer is any data source putting data records into a stream, for example with PutRecords). The timestamp has millisecond precision. There are no guarantees about the timestamp accuracy, or that the timestamp is always increasing. For example, records in a shard or across a stream might have timestamps that are out of order.

Note:

For PCL and Unity this operation is only available in asynchronous form. Please refer to GetRecordsAsync.

Namespace: Amazon.Kinesis
Assembly: AWSSDK.Kinesis.dll
Version: 3.x.y.z

Syntax

C#
public virtual GetRecordsResponse GetRecords(
         GetRecordsRequest request
)
Parameters
request
Type: Amazon.Kinesis.Model.GetRecordsRequest

Container for the necessary parameters to execute the GetRecords service method.

Return Value
The response from the GetRecords service method, as returned by Kinesis.

Exceptions

ExceptionCondition
ExpiredIteratorException The provided iterator exceeds the maximum age allowed.
InvalidArgumentException A specified parameter exceeds its restrictions, is not supported, or can't be used. For more information, see the returned message.
KMSAccessDeniedException The ciphertext references a key that doesn't exist or that you don't have access to.
KMSDisabledException The request was rejected because the specified CMK isn't enabled.
KMSInvalidStateException The request was rejected because the state of the specified resource isn't valid for this request. For more information, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
KMSNotFoundException The request was rejected because the specified entity or resource couldn't be found.
KMSOptInRequiredException The AWS access key ID needs a subscription for the service.
KMSThrottlingException The request was denied due to request throttling. For more information about throttling, see Limits in the AWS Key Management Service Developer Guide.
ProvisionedThroughputExceededException The request rate for the stream is too high, or the requested data is too large for the available throughput. Reduce the frequency or size of your requests. For more information, see Streams Limits in the Amazon Kinesis Streams Developer Guide, and Error Retries and Exponential Backoff in AWS in the AWS General Reference.
ResourceNotFoundException The requested resource could not be found. The stream might not be specified correctly.

Version Information

.NET Framework:
Supported in: 4.5, 4.0, 3.5

Portable Class Library:
Supported in: Windows Store Apps
Supported in: Windows Phone 8.1
Supported in: Xamarin Android
Supported in: Xamarin iOS (Unified)
Supported in: Xamarin.Forms

Unity:
Supported Versions: 4.6 and above
Supported Platforms: Android, iOS, Standalone

See Also