describe-stream¶

Description¶

Returns information about a stream, including the current status of the stream, its Amazon Resource Name (ARN), the composition of its shards, and its corresponding DynamoDB table.

Note

You can call DescribeStream at a maximum rate of 10 times per second.

Each shard in the stream has a SequenceNumberRange associated with it. If the SequenceNumberRange has a StartingSequenceNumber but no EndingSequenceNumber , then the shard is still open (able to receive more stream records). If both StartingSequenceNumber and EndingSequenceNumber are present, then that shard is closed and can no longer receive more data.

Synopsis¶

  describe-stream
--stream-arn <value>
[--limit <value>]
[--exclusive-start-shard-id <value>]
[--cli-input-json | --cli-input-yaml]
[--generate-cli-skeleton <value>]

Options¶

--stream-arn (string)

The Amazon Resource Name (ARN) for the stream.

--limit (integer)

The maximum number of shard objects to return. The upper limit is 100.

--exclusive-start-shard-id (string)

The shard ID of the first item that this operation will evaluate. Use the value that was returned for LastEvaluatedShardId in the previous operation.

--cli-input-json | --cli-input-yaml (string) Reads arguments from the JSON string provided. The JSON string follows the format provided by --generate-cli-skeleton. If other arguments are provided on the command line, those values will override the JSON-provided values. It is not possible to pass arbitrary binary values using a JSON-provided value as the string will be taken literally. This may not be specified along with --cli-input-yaml.

--generate-cli-skeleton (string) Prints a JSON skeleton to standard output without sending an API request. If provided with no value or the value input, prints a sample input JSON that can be used as an argument for --cli-input-json. Similarly, if provided yaml-input it will print a sample input YAML that can be used with --cli-input-yaml. If provided with the value output, it validates the command inputs and returns a sample output JSON for that command.

See ‘aws help’ for descriptions of global parameters.

Examples¶

To get information about a DynamoDB stream

The following describe-stream command displays information about the specific DynamoDB stream.

aws dynamodbstreams describe-stream \
    --stream-arn arn:aws:dynamodb:us-west-1:123456789012:table/Music/stream/2019-10-22T18:02:01.576

Output:

{
    "StreamDescription": {
        "StreamArn": "arn:aws:dynamodb:us-west-1:123456789012:table/Music/stream/2019-10-22T18:02:01.576",
        "StreamLabel": "2019-10-22T18:02:01.576",
        "StreamStatus": "ENABLED",
        "StreamViewType": "NEW_AND_OLD_IMAGES",
        "CreationRequestDateTime": 1571767321.571,
        "TableName": "Music",
        "KeySchema": [
            {
                "AttributeName": "Artist",
                "KeyType": "HASH"
            },
            {
                "AttributeName": "SongTitle",
                "KeyType": "RANGE"
            }
        ],
        "Shards": [
            {
                "ShardId": "shardId-00000001571767321804-697ce3d2",
                "SequenceNumberRange": {
                    "StartingSequenceNumber": "4000000000000642977831",
                    "EndingSequenceNumber": "4000000000000642977831"
                }
            },
            {
                "ShardId": "shardId-00000001571780995058-40810d86",
                "SequenceNumberRange": {
                    "StartingSequenceNumber": "757400000000005655171150"
                },
                "ParentShardId": "shardId-00000001571767321804-697ce3d2"
            }
        ]
    }
}

For more information, see Capturing Table Activity with DynamoDB Streams in the Amazon DynamoDB Developer Guide.

Output¶

StreamDescription -> (structure)

A complete description of the stream, including its creation date and time, the DynamoDB table associated with the stream, the shard IDs within the stream, and the beginning and ending sequence numbers of stream records within the shards.

StreamArn -> (string)

The Amazon Resource Name (ARN) for the stream.

StreamLabel -> (string)

A timestamp, in ISO 8601 format, for this stream.

Note that LatestStreamLabel is not a unique identifier for the stream, because it is possible that a stream from another table might have the same timestamp. However, the combination of the following three elements is guaranteed to be unique:

the AWS customer ID.

the table name

the StreamLabel

StreamStatus -> (string)

Indicates the current status of the stream:

ENABLING - Streams is currently being enabled on the DynamoDB table.

ENABLED - the stream is enabled.

DISABLING - Streams is currently being disabled on the DynamoDB table.

DISABLED - the stream is disabled.

StreamViewType -> (string)

Indicates the format of the records within this stream:

KEYS_ONLY - only the key attributes of items that were modified in the DynamoDB table.

NEW_IMAGE - entire items from the table, as they appeared after they were modified.

OLD_IMAGE - entire items from the table, as they appeared before they were modified.

NEW_AND_OLD_IMAGES - both the new and the old images of the items from the table.

CreationRequestDateTime -> (timestamp)

The date and time when the request to create this stream was issued.

TableName -> (string)

The DynamoDB table with which the stream is associated.

KeySchema -> (list)

The key attribute(s) of the stream’s DynamoDB table.

(structure)

Represents a single element of a key schema. A key schema specifies the attributes that make up the primary key of a table, or the key attributes of an index.

A KeySchemaElement represents exactly one attribute of the primary key. For example, a simple primary key would be represented by one KeySchemaElement (for the partition key). A composite primary key would require one KeySchemaElement for the partition key, and another KeySchemaElement for the sort key.

A KeySchemaElement must be a scalar, top-level attribute (not a nested attribute). The data type must be one of String, Number, or Binary. The attribute cannot be nested within a List or a Map.

AttributeName -> (string)

The name of a key attribute.

KeyType -> (string)

The role that this key attribute will assume:

HASH - partition key

RANGE - sort key

Note

The partition key of an item is also known as its hash attribute . The term “hash attribute” derives from DynamoDB’s usage of an internal hash function to evenly distribute data items across partitions, based on their partition key values.

The sort key of an item is also known as its range attribute . The term “range attribute” derives from the way DynamoDB stores items with the same partition key physically close together, in sorted order by the sort key value.

Shards -> (list)

The shards that comprise the stream.

(structure)

A uniquely identified group of stream records within a stream.

ShardId -> (string)

The system-generated identifier for this shard.

SequenceNumberRange -> (structure)

The range of possible sequence numbers for the shard.

StartingSequenceNumber -> (string)

The first sequence number for the stream records contained within a shard. String contains numeric characters only.

EndingSequenceNumber -> (string)

The last sequence number for the stream records contained within a shard. String contains numeric characters only.

ParentShardId -> (string)

The shard ID of the current shard’s parent.

LastEvaluatedShardId -> (string)

The shard ID of the item where the operation stopped, inclusive of the previous result set. Use this value to start a new operation, excluding this value in the new request.

If LastEvaluatedShardId is empty, then the “last page” of results has been processed and there is currently no more data to be retrieved.

If LastEvaluatedShardId is not empty, it does not necessarily mean that there is more data in the result set. The only way to know when you have reached the end of the result set is when LastEvaluatedShardId is empty.

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