:doc:`Kinesis <../../kinesis>` / Client / get_shard_iterator

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get_shard_iterator
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.. py:method:: Kinesis.Client.get_shard_iterator(**kwargs)

  

  Gets an Amazon Kinesis shard iterator. A shard iterator expires 5 minutes after it is returned to the requester.

   

  .. note::

    

    When invoking this API, you must use either the ``StreamARN`` or the ``StreamName`` parameter, or both. It is recommended that you use the ``StreamARN`` input parameter when you invoke this API.

    

   

  A shard iterator specifies the shard position from which to start reading data records sequentially. The position is specified using the sequence number of a data record in a shard. A sequence number is the identifier associated with every record ingested in the stream, and is assigned when a record is put into the stream. Each stream has one or more shards.

   

  You must specify the shard iterator type. For example, you can set the ``ShardIteratorType`` parameter to read exactly from the position denoted by a specific sequence number by using the ``AT_SEQUENCE_NUMBER`` shard iterator type. Alternatively, the parameter can read right after the sequence number by using the ``AFTER_SEQUENCE_NUMBER`` shard iterator type, using sequence numbers returned by earlier calls to  PutRecord,  PutRecords,  GetRecords, or  DescribeStream. In the request, you can specify the shard iterator type ``AT_TIMESTAMP`` to read records from an arbitrary point in time, ``TRIM_HORIZON`` to cause ``ShardIterator`` to point to the last untrimmed record in the shard in the system (the oldest data record in the shard), or ``LATEST`` so that you always read the most recent data in the shard.

   

  When you read repeatedly from a stream, use a  GetShardIterator request to get the first shard iterator for use in your first  GetRecords request and for subsequent reads use the shard iterator returned by the  GetRecords request in ``NextShardIterator``. A new shard iterator is returned by every  GetRecords request in ``NextShardIterator``, which you use in the ``ShardIterator`` parameter of the next  GetRecords request.

   

  If a  GetShardIterator request is made too often, you receive a ``ProvisionedThroughputExceededException``. For more information about throughput limits, see  GetRecords, and `Streams Limits <https://docs.aws.amazon.com/kinesis/latest/dev/service-sizes-and-limits.html>`__ in the *Amazon Kinesis Data Streams Developer Guide*.

   

  If the shard is closed,  GetShardIterator returns a valid iterator for the last sequence number of the shard. A shard can be closed as a result of using  SplitShard or  MergeShards.

   

   GetShardIterator has a limit of five transactions per second per account per open shard.

  

  See also: `AWS API Documentation <https://docs.aws.amazon.com/goto/WebAPI/kinesis-2013-12-02/GetShardIterator>`_  


  **Request Syntax**
  ::

    response = client.get_shard_iterator(
        StreamName='string',
        ShardId='string',
        ShardIteratorType='AT_SEQUENCE_NUMBER'|'AFTER_SEQUENCE_NUMBER'|'TRIM_HORIZON'|'LATEST'|'AT_TIMESTAMP',
        StartingSequenceNumber='string',
        Timestamp=datetime(2015, 1, 1),
        StreamARN='string',
        StreamId='string'
    )
    
  :type StreamName: string
  :param StreamName: 

    The name of the Amazon Kinesis data stream.

    

  
  :type ShardId: string
  :param ShardId: **[REQUIRED]** 

    The shard ID of the Kinesis Data Streams shard to get the iterator for.

    

  
  :type ShardIteratorType: string
  :param ShardIteratorType: **[REQUIRED]** 

    Determines how the shard iterator is used to start reading data records from the shard.

     

    The following are the valid Amazon Kinesis shard iterator types:

     

    
    * AT_SEQUENCE_NUMBER - Start reading from the position denoted by a specific sequence number, provided in the value ``StartingSequenceNumber``.
     
    * AFTER_SEQUENCE_NUMBER - Start reading right after the position denoted by a specific sequence number, provided in the value ``StartingSequenceNumber``.
     
    * AT_TIMESTAMP - Start reading from the position denoted by a specific time stamp, provided in the value ``Timestamp``.
     
    * TRIM_HORIZON - Start reading at the last untrimmed record in the shard in the system, which is the oldest data record in the shard.
     
    * LATEST - Start reading just after the most recent record in the shard, so that you always read the most recent data in the shard.
    

    

  
  :type StartingSequenceNumber: string
  :param StartingSequenceNumber: 

    The sequence number of the data record in the shard from which to start reading. Used with shard iterator type AT_SEQUENCE_NUMBER and AFTER_SEQUENCE_NUMBER.

    

  
  :type Timestamp: datetime
  :param Timestamp: 

    The time stamp of the data record from which to start reading. Used with shard iterator type AT_TIMESTAMP. A time stamp is the Unix epoch date with precision in milliseconds. For example, ``2016-04-04T19:58:46.480-00:00`` or ``1459799926.480``. If a record with this exact time stamp does not exist, the iterator returned is for the next (later) record. If the time stamp is older than the current trim horizon, the iterator returned is for the oldest untrimmed data record (TRIM_HORIZON).

    

  
  :type StreamARN: string
  :param StreamARN: 

    The ARN of the stream.

    

  
  :type StreamId: string
  :param StreamId: 

    Not Implemented. Reserved for future use.

    

  
  
  :rtype: dict
  :returns: 
    
    **Response Syntax**

    
    ::

      {
          'ShardIterator': 'string'
      }
      
    **Response Structure**

    

    - *(dict) --* 

      Represents the output for ``GetShardIterator``.

      
      

      - **ShardIterator** *(string) --* 

        The position in the shard from which to start reading data records sequentially. A shard iterator specifies this position using the sequence number of a data record in a shard.

        
  
  **Exceptions**
  
  *   :py:class:`Kinesis.Client.exceptions.ResourceNotFoundException`

  
  *   :py:class:`Kinesis.Client.exceptions.InvalidArgumentException`

  
  *   :py:class:`Kinesis.Client.exceptions.ProvisionedThroughputExceededException`

  
  *   :py:class:`Kinesis.Client.exceptions.AccessDeniedException`

  
  *   :py:class:`Kinesis.Client.exceptions.InternalFailureException`

  