2014/10/16 - Amazon Kinesis - 12 new api methods
Creates a Amazon Kinesis stream. A stream captures and transports data records that are continuously emitted from different data sources or producers . Scale-out within an Amazon Kinesis stream is explicitly supported by means of shards, which are uniquely identified groups of data records in an Amazon Kinesis stream.
You specify and control the number of shards that a stream is composed of. Each open shard can support up to 5 read transactions per second, up to a maximum total of 2 MB of data read per second. Each shard can support up to 1000 write transactions per second, up to a maximum total of 1 MB data written per second. You can add shards to a stream if the amount of data input increases and you can remove shards if the amount of data input decreases.
The stream name identifies the stream. The name is scoped to the AWS account used by the application. It is also scoped by region. That is, two streams in two different accounts can have the same name, and two streams in the same account, but in two different regions, can have the same name.
CreateStream is an asynchronous operation. Upon receiving a CreateStream request, Amazon Kinesis immediately returns and sets the stream status to CREATING . After the stream is created, Amazon Kinesis sets the stream status to ACTIVE . You should perform read and write operations only on an ACTIVE stream.
You receive a LimitExceededException when making a CreateStream request if you try to do one of the following:
Have more than five streams in the CREATING state at any point in time.
Create more shards than are authorized for your account.
The default limit for an AWS account is 10 shards per stream. If you need to create a stream with more than 10 shards, contact AWS Support to increase the limit on your account.
You can use DescribeStream to check the stream status, which is returned in StreamStatus .
CreateStream has a limit of 5 transactions per second per account.
Request Syntax
client.create_stream(
StreamName='string',
ShardCount=123
)
string
[REQUIRED]
A name to identify the stream. The stream name is scoped to the AWS account used by the application that creates the stream. It is also scoped by region. That is, two streams in two different AWS accounts can have the same name, and two streams in the same AWS account, but in two different regions, can have the same name.
integer
[REQUIRED]
The number of shards that the stream will use. The throughput of the stream is a function of the number of shards; more shards are required for greater provisioned throughput.
Note: The default limit for an AWS account is 10 shards per stream. If you need to create a stream with more than 10 shards, contact AWS Support to increase the limit on your account.
None
Merges two adjacent shards in a stream and combines them into a single shard to reduce the stream's capacity to ingest and transport data. Two shards are considered adjacent if the union of the hash key ranges for the two shards form a contiguous set with no gaps. For example, if you have two shards, one with a hash key range of 276...381 and the other with a hash key range of 382...454, then you could merge these two shards into a single shard that would have a hash key range of 276...454. After the merge, the single child shard receives data for all hash key values covered by the two parent shards.
MergeShards is called when there is a need to reduce the overall capacity of a stream because of excess capacity that is not being used. You must specify the shard to be merged and the adjacent shard for a stream. For more information about merging shards, see Merge Two Shards in the Amazon Kinesis Developer Guide .
If the stream is in the ACTIVE state, you can call MergeShards . If a stream is in the CREATING , UPDATING , or DELETING state, MergeShards returns a ResourceInUseException . If the specified stream does not exist, MergeShards returns a ResourceNotFoundException .
You can use DescribeStream to check the state of the stream, which is returned in StreamStatus .
MergeShards is an asynchronous operation. Upon receiving a MergeShards request, Amazon Kinesis immediately returns a response and sets the StreamStatus to UPDATING . After the operation is completed, Amazon Kinesis sets the StreamStatus to ACTIVE . Read and write operations continue to work while the stream is in the UPDATING state.
You use DescribeStream to determine the shard IDs that are specified in the MergeShards request.
If you try to operate on too many streams in parallel using CreateStream, DeleteStream, MergeShards or SplitShard, you will receive a LimitExceededException .
MergeShards has limit of 5 transactions per second per account.
Request Syntax
client.merge_shards(
StreamName='string',
ShardToMerge='string',
AdjacentShardToMerge='string'
)
string
[REQUIRED]
The name of the stream for the merge.
string
[REQUIRED]
The shard ID of the shard to combine with the adjacent shard for the merge.
string
[REQUIRED]
The shard ID of the adjacent shard for the merge.
None
Splits a shard into two new shards in the 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 stream because of an expected increase in the volume of data records being ingested.
You can also use SplitShard when a shard appears to be approaching its maximum utilization, for example, when the set of 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 Amazon Kinesis 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 simply 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 about splitting shards, see Split a Shard in the Amazon Kinesis Developer Guide .
You can use DescribeStream 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, Amazon Kinesis immediately returns a response and sets the stream status to UPDATING . After the operation is completed, Amazon Kinesis sets the stream status to ACTIVE . Read and write operations continue to work while the stream is in the UPDATING state.
You can use DescribeStream 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 a stream is in CREATING or UPDATING or DELETING states, DescribeStream returns a ResourceInUseException .
If the specified stream does not exist, DescribeStream returns a ResourceNotFoundException . If you try to create more shards than are authorized for your account, you receive a LimitExceededException .
The default limit for an AWS account is 10 shards per stream. If you need to create a stream with more than 10 shards, contact AWS Support to increase the limit on your account.
If you try to operate on too many streams in parallel using CreateStream, DeleteStream, MergeShards or SplitShard, you receive a LimitExceededException .
SplitShard has limit of 5 transactions per second per account.
Request Syntax
client.split_shard(
StreamName='string',
ShardToSplit='string',
NewStartingHashKey='string'
)
string
[REQUIRED]
The name of the stream for the shard split.
string
[REQUIRED]
The shard ID of the shard to split.
string
[REQUIRED]
A hash key value for the starting hash key of one of the child shards created by the split. The hash key range for a given shard constitutes a set of ordered contiguous positive integers. The value for NewStartingHashKey must be in the range of hash keys being mapped into the shard. The NewStartingHashKey hash key value and all higher hash key values in hash key range are distributed to one of the child shards. All the lower hash key values in the range are distributed to the other child shard.
None
Adds or updates tags for the specified Amazon Kinesis stream. Each stream can have up to 10 tags.
If tags have already been assigned to the stream, AddTagsToStream overwrites any existing tags that correspond to the specified tag keys.
Request Syntax
client.add_tags_to_stream(
StreamName='string',
Tags={
'string': 'string'
}
)
string
[REQUIRED]
The name of the stream.
dict
[REQUIRED]
The set of key-value pairs to use to create the tags.
(string) --
(string) --
None
Puts a data record from a producer into an Amazon Kinesis stream. You must call PutRecord to send data from the producer into the Amazon Kinesis stream for real-time ingestion and subsequent processing. You must specify the name of the stream that captures, stores, and transports the data; a partition key; and the data blob itself. The data blob could be a segment from a log file, geographic/location data, website clickstream data, or any other data type.
The partition key is used to distribute data across shards. Amazon Kinesis segregates the data records that belong to a data stream into multiple shards, using the partition key associated with each data record to determine which shard a given data record belongs to.
Partition keys are Unicode strings, with a maximum length limit of 256 bytes. An MD5 hash function is used to map partition keys to 128-bit integer values and to map associated data records to shards using the hash key ranges of the shards. You can override hashing the partition key to determine the shard by explicitly specifying a hash value using the ExplicitHashKey parameter. For more information, see Partition Key in the Amazon Kinesis Developer Guide .
PutRecord returns the shard ID of where the data record was placed and the sequence number that was assigned to the data record.
Sequence numbers generally increase over time. To guarantee strictly increasing ordering, use the SequenceNumberForOrdering parameter. For more information, see Sequence Number in the Amazon Kinesis Developer Guide .
If a PutRecord request cannot be processed because of insufficient provisioned throughput on the shard involved in the request, PutRecord throws ProvisionedThroughputExceededException .
Data records are accessible for only 24 hours from the time that they are added to an Amazon Kinesis stream.
Request Syntax
client.put_record(
StreamName='string',
Data=b'bytes',
PartitionKey='string',
ExplicitHashKey='string',
SequenceNumberForOrdering='string'
)
string
[REQUIRED]
The name of the stream to put the data record into.
bytes
[REQUIRED]
The data blob to put into the record, which is Base64-encoded when the blob is serialized. The maximum size of the data blob (the payload before Base64-encoding) is 50 kilobytes (KB)
string
[REQUIRED]
Determines which shard in the stream the data record is assigned to. Partition keys are Unicode strings with a maximum length limit of 256 bytes. Amazon Kinesis uses the partition key as input to a hash function that maps the partition key and associated data to a specific shard. Specifically, an MD5 hash function is used to map partition keys to 128-bit integer values and to map associated data records to shards. As a result of this hashing mechanism, all data records with the same partition key will map to the same shard within the stream.
string
The hash value used to explicitly determine the shard the data record is assigned to by overriding the partition key hash.
string
Guarantees strictly increasing sequence numbers, for puts from the same client and to the same partition key. Usage: set the SequenceNumberForOrdering of record n to the sequence number of record n-1 (as returned in the PutRecordResult when putting record n-1 ). If this parameter is not set, records will be coarsely ordered based on arrival time.
dict
Response Syntax
{
'ShardId': 'string',
'SequenceNumber': 'string'
}
Response Structure
(dict) --
Represents the output for PutRecord .
ShardId (string) --
The shard ID of the shard where the data record was placed.
SequenceNumber (string) --
The sequence number identifier that was assigned to the put data record. The sequence number for the record is unique across all records in the stream. A sequence number is the identifier associated with every record put into the stream.
Lists the tags for the specified Amazon Kinesis stream.
Request Syntax
client.list_tags_for_stream(
StreamName='string',
ExclusiveStartTagKey='string',
Limit=123
)
string
[REQUIRED]
The name of the stream.
string
The key to use as the starting point for the list of tags. If this parameter is set, ListTagsForStream gets all tags that occur after ExclusiveStartTagKey .
integer
The number of tags to return. If this number is less than the total number of tags associated with the stream, HasMoreTags is set to true . To list additional tags, set ExclusiveStartTagKey to the last key in the response.
dict
Response Syntax
{
'Tags': [
{
'Key': 'string',
'Value': 'string'
},
],
'HasMoreTags': True|False
}
Response Structure
(dict) --
Represents the output for ListTagsForStream .
Tags (list) --
A list of tags associated with StreamName , starting with the first tag after ExclusiveStartTagKey and up to the specified Limit .
(dict) --
Metadata assigned to the stream, consisting of a key-value pair.
Key (string) --
A unique identifier for the tag. Maximum length: 128 characters. Valid characters: Unicode letters, digits, white space, _ . / = + - % @
Value (string) --
An optional string, typically used to describe or define the tag. Maximum length: 256 characters. Valid characters: Unicode letters, digits, white space, _ . / = + - % @
HasMoreTags (boolean) --
If set to true , more tags are available. To request additional tags, set ExclusiveStartTagKey to the key of the last tag returned.
Describes the specified stream.
The information about the stream includes its current status, its Amazon Resource Name (ARN), and an array of shard objects. For each shard object, there is information about the hash key and sequence number ranges that the shard spans, and the IDs of any earlier shards that played in a role in creating the shard. A sequence number is the identifier associated with every record ingested in the Amazon Kinesis stream. The sequence number is assigned when a record is put into the stream.
You can limit the number of returned shards using the Limit parameter. The number of shards in a stream may be too large to return from a single call to DescribeStream . You can detect this by using the HasMoreShards flag in the returned output. HasMoreShards is set to true when there is more data available.
DescribeStream is a paginated operation. If there are more shards available, you can request them using the shard ID of the last shard returned. Specify this ID in the ExclusiveStartShardId parameter in a subsequent request to DescribeStream .
DescribeStream has a limit of 10 transactions per second per account.
Request Syntax
client.describe_stream(
StreamName='string',
Limit=123,
ExclusiveStartShardId='string'
)
string
[REQUIRED]
The name of the stream to describe.
integer
The maximum number of shards to return.
string
The shard ID of the shard to start with.
dict
Response Syntax
{
'StreamDescription': {
'StreamName': 'string',
'StreamARN': 'string',
'StreamStatus': 'CREATING'|'DELETING'|'ACTIVE'|'UPDATING',
'Shards': [
{
'ShardId': 'string',
'ParentShardId': 'string',
'AdjacentParentShardId': 'string',
'HashKeyRange': {
'StartingHashKey': 'string',
'EndingHashKey': 'string'
},
'SequenceNumberRange': {
'StartingSequenceNumber': 'string',
'EndingSequenceNumber': 'string'
}
},
],
'HasMoreShards': True|False
}
}
Response Structure
(dict) --
Represents the output for DescribeStream .
StreamDescription (dict) --
The current status of the stream, the stream ARN, an array of shard objects that comprise the stream, and states whether there are more shards available.
StreamName (string) --
The name of the stream being described.
StreamARN (string) --
The Amazon Resource Name (ARN) for the stream being described.
StreamStatus (string) --
The current status of the stream being described.
The stream status is one of the following states:
CREATING - The stream is being created. Amazon Kinesis immediately returns and sets StreamStatus to CREATING .
DELETING - The stream is being deleted. The specified stream is in the DELETING state until Amazon Kinesis completes the deletion.
ACTIVE - The stream exists and is ready for read and write operations or deletion. You should perform read and write operations only on an ACTIVE stream.
UPDATING - Shards in the stream are being merged or split. Read and write operations continue to work while the stream is in the UPDATING state.
Shards (list) --
The shards that comprise the stream.
(dict) --
A uniquely identified group of data records in an Amazon Kinesis stream.
ShardId (string) --
The unique identifier of the shard within the Amazon Kinesis stream.
ParentShardId (string) --
The shard Id of the shard's parent.
AdjacentParentShardId (string) --
The shard Id of the shard adjacent to the shard's parent.
HashKeyRange (dict) --
The range of possible hash key values for the shard, which is a set of ordered contiguous positive integers.
StartingHashKey (string) --
The starting hash key of the hash key range.
EndingHashKey (string) --
The ending hash key of the hash key range.
SequenceNumberRange (dict) --
The range of possible sequence numbers for the shard.
StartingSequenceNumber (string) --
The starting sequence number for the range.
EndingSequenceNumber (string) --
The ending sequence number for the range. Shards that are in the OPEN state have an ending sequence number of null .
HasMoreShards (boolean) --
If set to true , more shards in the stream are available to describe.
Gets data records from a 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. 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 50 KB 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 specifying the maximum number of records that GetRecords can return in the Limit parameter. Consider your average record size when determining this limit. For example, if your average record size is 40 KB, you can limit the data returned to about 1 MB per call by specifying 25 as the limit.
The size of the data returned by GetRecords will vary depending on the utilization of the shard. The maximum size of data that GetRecords can return is 10 MB. If a call returns 10 MB 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, add a timestamp to your records and note how long it takes to process them. You can also monitor how much data is in a stream using the CloudWatch metrics for PutRecord . For more information, see Monitoring Amazon Kinesis with Amazon CloudWatch in the Amazon Kinesis Developer Guide .
Request Syntax
client.get_records(
ShardIterator='string',
Limit=123
)
string
[REQUIRED]
The position in the shard from which you want to start sequentially reading data records. A shard iterator specifies this position using the sequence number of a data record in the shard.
integer
The maximum number of records to return. Specify a value of up to 10,000. If you specify a value that is greater than 10,000, GetRecords throws InvalidArgumentException .
dict
Response Syntax
{
'Records': [
{
'SequenceNumber': 'string',
'Data': b'bytes',
'PartitionKey': 'string'
},
],
'NextShardIterator': 'string'
}
Response Structure
(dict) --
Represents the output for GetRecords .
Records (list) --
The data records retrieved from the shard.
(dict) --
The unit of data of the Amazon Kinesis stream, which is composed of a sequence number, a partition key, and a data blob.
SequenceNumber (string) --
The unique identifier for the record in the Amazon Kinesis stream.
Data (bytes) --
The data blob. The data in the blob is both opaque and immutable to the Amazon Kinesis service, which does not inspect, interpret, or change the data in the blob in any way. The maximum size of the data blob (the payload before Base64-encoding) is 50 kilobytes (KB)
PartitionKey (string) --
Identifies which shard in the stream the data record is assigned to.
NextShardIterator (string) --
The next position in the shard from which to start sequentially reading data records. If set to null , the shard has been closed and the requested iterator will not return any more data.
Lists your streams.
The number of streams may be too large to return from a single call to ListStreams . You can limit the number of returned streams using the Limit parameter. If you do not specify a value for the Limit parameter, Amazon Kinesis uses the default limit, which is currently 10.
You can detect if there are more streams available to list by using the HasMoreStreams flag from the returned output. If there are more streams available, you can request more streams by using the name of the last stream returned by the ListStreams request in the ExclusiveStartStreamName parameter in a subsequent request to ListStreams . The group of stream names returned by the subsequent request is then added to the list. You can continue this process until all the stream names have been collected in the list.
ListStreams has a limit of 5 transactions per second per account.
Request Syntax
client.list_streams(
Limit=123,
ExclusiveStartStreamName='string'
)
integer
The maximum number of streams to list.
string
The name of the stream to start the list with.
dict
Response Syntax
{
'StreamNames': [
'string',
],
'HasMoreStreams': True|False
}
Response Structure
(dict) --
Represents the output for ListStreams .
StreamNames (list) --
The names of the streams that are associated with the AWS account making the ListStreams request.
(string) --
HasMoreStreams (boolean) --
If set to true , there are more streams available to list.
Deletes tags from the specified Amazon Kinesis stream.
If you specify a tag that does not exist, it is ignored.
Request Syntax
client.remove_tags_from_stream(
StreamName='string',
TagKeys=[
'string',
]
)
string
[REQUIRED]
The name of the stream.
list
[REQUIRED]
A list of tag keys. Each corresponding tag is removed from the stream.
(string) --
None
Deletes a stream and all its shards and data. You must shut down any applications that are operating on the stream before you delete the stream. If an application attempts to operate on a deleted stream, it will receive the exception ResourceNotFoundException .
If the stream is in the ACTIVE state, you can delete it. After a DeleteStream request, the specified stream is in the DELETING state until Amazon Kinesis completes the deletion.
Note: Amazon Kinesis might continue to accept data read and write operations, such as PutRecord and GetRecords, on a stream in the DELETING state until the stream deletion is complete.
When you delete a stream, any shards in that stream are also deleted, and any tags are dissociated from the stream.
You can use the DescribeStream operation to check the state of the stream, which is returned in StreamStatus .
DeleteStream has a limit of 5 transactions per second per account.
Request Syntax
client.delete_stream(
StreamName='string'
)
string
[REQUIRED]
The name of the stream to delete.
None
Gets a shard iterator. A shard iterator expires five minutes after it is returned to the requester.
A shard iterator specifies 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. A sequence number is the identifier associated with every record ingested in the Amazon Kinesis stream. The sequence number is assigned when a record is put into the stream.
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, or right after the sequence number by using the AFTER_SEQUENCE_NUMBER shard iterator type, using sequence numbers returned by earlier calls to PutRecord, GetRecords, or DescribeStream. You can specify the shard iterator type TRIM_HORIZON in the request to cause ShardIterator to point to the last untrimmed record in the shard in the system, which is the oldest data record in the shard. Or you can point to just after the most recent record in the shard, by using the shard iterator type LATEST , so that you always read the most recent data in the shard.
When you repeatedly read from an Amazon Kinesis stream use a GetShardIterator request to get the first shard iterator to to use in your first GetRecords request and then use the shard iterator returned by the GetRecords request in NextShardIterator for subsequent reads. 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.
If the shard is closed, the iterator can't return more data, and GetShardIterator returns null for its ShardIterator . A shard can be closed using SplitShard or MergeShards.
GetShardIterator has a limit of 5 transactions per second per account per open shard.
Request Syntax
client.get_shard_iterator(
StreamName='string',
ShardId='string',
ShardIteratorType='AT_SEQUENCE_NUMBER'|'AFTER_SEQUENCE_NUMBER'|'TRIM_HORIZON'|'LATEST',
StartingSequenceNumber='string'
)
string
[REQUIRED]
The name of the stream.
string
[REQUIRED]
The shard ID of the shard to get the iterator for.
string
[REQUIRED]
Determines how the shard iterator is used to start reading data records from the shard.
The following are the valid shard iterator types:
AT_SEQUENCE_NUMBER - Start reading exactly from the position denoted by a specific sequence number.
AFTER_SEQUENCE_NUMBER - Start reading right after the position denoted by a specific sequence number.
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.
string
The sequence number of the data record in the shard from which to start reading from.
dict
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.