GetRecords - Amazon DynamoDB

GetRecords

Retrieves the stream records from a given 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 stream records sequentially. If there are no stream 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 stream records.

Note

GetRecords can retrieve a maximum of 1 MB of data or 1000 stream records, whichever comes first.

Request Syntax

{ "Limit": number, "ShardIterator": "string" }

Request Parameters

The request accepts the following data in JSON format.

Note

In the following list, the required parameters are described first.

ShardIterator

A shard iterator that was retrieved from a previous GetShardIterator operation. This iterator can be used to access the stream records in this shard.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 2048.

Required: Yes

Limit

The maximum number of records to return from the shard. The upper limit is 1000.

Type: Integer

Valid Range: Minimum value of 1.

Required: No

Response Syntax

{ "NextShardIterator": "string", "Records": [ { "awsRegion": "string", "dynamodb": { "ApproximateCreationDateTime": number, "Keys": { "string" : { "B": blob, "BOOL": boolean, "BS": [ blob ], "L": [ "AttributeValue" ], "M": { "string" : "AttributeValue" }, "N": "string", "NS": [ "string" ], "NULL": boolean, "S": "string", "SS": [ "string" ] } }, "NewImage": { "string" : { "B": blob, "BOOL": boolean, "BS": [ blob ], "L": [ "AttributeValue" ], "M": { "string" : "AttributeValue" }, "N": "string", "NS": [ "string" ], "NULL": boolean, "S": "string", "SS": [ "string" ] } }, "OldImage": { "string" : { "B": blob, "BOOL": boolean, "BS": [ blob ], "L": [ "AttributeValue" ], "M": { "string" : "AttributeValue" }, "N": "string", "NS": [ "string" ], "NULL": boolean, "S": "string", "SS": [ "string" ] } }, "SequenceNumber": "string", "SizeBytes": number, "StreamViewType": "string" }, "eventID": "string", "eventName": "string", "eventSource": "string", "eventVersion": "string", "userIdentity": { "PrincipalId": "string", "Type": "string" } } ] }

Response Elements

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

The following data is returned in JSON format by the service.

NextShardIterator

The next position in the shard from which to start sequentially reading stream records. If set to null, the shard has been closed and the requested iterator will not return any more data.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 2048.

Records

The stream records from the shard, which were retrieved using the shard iterator.

Type: Array of Record objects

Errors

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

ExpiredIteratorException

The shard iterator has expired and can no longer be used to retrieve stream records. A shard iterator expires 15 minutes after it is retrieved using the GetShardIterator action.

HTTP Status Code: 400

InternalServerError

An error occurred on the server side.

HTTP Status Code: 500

LimitExceededException

There is no limit to the number of daily on-demand backups that can be taken.

For most purposes, up to 500 simultaneous table operations are allowed per account. These operations include CreateTable, UpdateTable, DeleteTable,UpdateTimeToLive, RestoreTableFromBackup, and RestoreTableToPointInTime.

When you are creating a table with one or more secondary indexes, you can have up to 250 such requests running at a time. However, if the table or index specifications are complex, then DynamoDB might temporarily reduce the number of concurrent operations.

When importing into DynamoDB, up to 50 simultaneous import table operations are allowed per account.

There is a soft account quota of 2,500 tables.

GetRecords was called with a value of more than 1000 for the limit request parameter.

More than 2 processes are reading from the same streams shard at the same time. Exceeding this limit may result in request throttling.

HTTP Status Code: 400

ResourceNotFoundException

The operation tried to access a nonexistent table or index. The resource might not be specified correctly, or its status might not be ACTIVE.

HTTP Status Code: 400

TrimmedDataAccessException

The operation attempted to read past the oldest stream record in a shard.

In DynamoDB Streams, there is a 24 hour limit on data retention. Stream records whose age exceeds this limit are subject to removal (trimming) from the stream. You might receive a TrimmedDataAccessException if:

  • You request a shard iterator with a sequence number older than the trim point (24 hours).

  • You obtain a shard iterator, but before you use the iterator in a GetRecords request, a stream record in the shard exceeds the 24 hour period and is trimmed. This causes the iterator to access a record that no longer exists.

HTTP Status Code: 400

Examples

Retrieve stream records from a shard

The following sample retrieves all the stream records from a shard. To do this, it uses a ShardIterator that was obtained from a previous GetShardIterator call.

Sample Request

POST / HTTP/1.1 x-amzn-RequestId: <RequestID> x-amzn-crc32: <CRC32> Content-Type: application/x-amz-json-1.0 Content-Length: <PayloadSizeBytes> X-Amz-Date: <Date> X-Amz-Target: DynamoDBStreams_20120810.GetRecords { "ShardIterator": "arn:aws:dynamodb:us-west-2:111122223333:table/Forum/stream/2015-05-20T20:51:10.252|1|AAAAAAAAAAEvJp6D+zaQ... <remaining characters omitted> ..." }

Sample Response

HTTP/1.1 200 OK x-amzn-RequestId: <RequestId> x-amz-crc32: <Checksum> Content-Type: application/x-amz-json-1.0 Content-Length: <PayloadSizeBytes> Date: <Date> { "NextShardIterator": "arn:aws:dynamodb:us-west-2:111122223333:table/Forum/stream/2015-05-20T20:51:10.252|1|AAAAAAAAAAGQBYshYDEe ... <remaining characters omitted> ...", "Records": [ { "awsRegion": "us-west-2", "dynamodb": { "ApproximateCreationDateTime": 1.46480431E9, "Keys": { "ForumName": {"S": "DynamoDB"}, "Subject": {"S": "DynamoDB Thread 3"} }, "SequenceNumber": "300000000000000499659", "SizeBytes": 41, "StreamViewType": "KEYS_ONLY" }, "eventID": "e2fd9c34eff2d779b297b26f5fef4206", "eventName": "INSERT", "eventSource": "aws:dynamodb", "eventVersion": "1.0" }, { "awsRegion": "us-west-2", "dynamodb": { "ApproximateCreationDateTime": 1.46480527E9, "Keys": { "ForumName": {"S": "DynamoDB"}, "Subject": {"S": "DynamoDB Thread 1"} }, "SequenceNumber": "400000000000000499660", "SizeBytes": 41, "StreamViewType": "KEYS_ONLY" }, "eventID": "4b25bd0da9a181a155114127e4837252", "eventName": "MODIFY", "eventSource": "aws:dynamodb", "eventVersion": "1.0" }, { "awsRegion": "us-west-2", "dynamodb": { "ApproximateCreationDateTime": 1.46480646E9, "Keys": { "ForumName": {"S": "DynamoDB"}, "Subject": {"S": "DynamoDB Thread 2"} }, "SequenceNumber": "500000000000000499661", "SizeBytes": 41, "StreamViewType": "KEYS_ONLY" }, "eventID": "740280c73a3df7842edab3548a1b08ad", "eventName": "REMOVE", "eventSource": "aws:dynamodb", "eventVersion": "1.0" } ] }

See Also

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