| Copyright | (c) 2013-2021 Brendan Hay |
|---|---|
| License | Mozilla Public License, v. 2.0. |
| Maintainer | Brendan Hay <brendan.g.hay+amazonka@gmail.com> |
| Stability | auto-generated |
| Portability | non-portable (GHC extensions) |
| Safe Haskell | None |
Amazonka.Kinesis.GetShardIterator
Description
Gets an Amazon Kinesis shard iterator. A shard iterator expires 5 minutes after it is returned to the requester.
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
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.
Synopsis
- data GetShardIterator = GetShardIterator' {}
- newGetShardIterator :: Text -> Text -> ShardIteratorType -> GetShardIterator
- getShardIterator_startingSequenceNumber :: Lens' GetShardIterator (Maybe Text)
- getShardIterator_timestamp :: Lens' GetShardIterator (Maybe UTCTime)
- getShardIterator_streamName :: Lens' GetShardIterator Text
- getShardIterator_shardId :: Lens' GetShardIterator Text
- getShardIterator_shardIteratorType :: Lens' GetShardIterator ShardIteratorType
- data GetShardIteratorResponse = GetShardIteratorResponse' {
- shardIterator :: Maybe Text
- httpStatus :: Int
- newGetShardIteratorResponse :: Int -> GetShardIteratorResponse
- getShardIteratorResponse_shardIterator :: Lens' GetShardIteratorResponse (Maybe Text)
- getShardIteratorResponse_httpStatus :: Lens' GetShardIteratorResponse Int
Creating a Request
data GetShardIterator Source #
Represents the input for GetShardIterator.
See: newGetShardIterator smart constructor.
Constructors
| GetShardIterator' | |
Fields
| |
Instances
Arguments
| :: Text | |
| -> Text | |
| -> ShardIteratorType | |
| -> GetShardIterator |
Create a value of GetShardIterator with all optional fields omitted.
Use generic-lens or optics to modify other optional fields.
The following record fields are available, with the corresponding lenses provided for backwards compatibility:
$sel:startingSequenceNumber:GetShardIterator', getShardIterator_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.
$sel:timestamp:GetShardIterator', getShardIterator_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).
$sel:streamName:GetShardIterator', getShardIterator_streamName - The name of the Amazon Kinesis data stream.
$sel:shardId:GetShardIterator', getShardIterator_shardId - The shard ID of the Kinesis Data Streams shard to get the iterator for.
$sel:shardIteratorType:GetShardIterator', getShardIterator_shardIteratorType - 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.
Request Lenses
getShardIterator_startingSequenceNumber :: Lens' GetShardIterator (Maybe Text) Source #
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.
getShardIterator_timestamp :: Lens' GetShardIterator (Maybe UTCTime) Source #
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).
getShardIterator_streamName :: Lens' GetShardIterator Text Source #
The name of the Amazon Kinesis data stream.
getShardIterator_shardId :: Lens' GetShardIterator Text Source #
The shard ID of the Kinesis Data Streams shard to get the iterator for.
getShardIterator_shardIteratorType :: Lens' GetShardIterator ShardIteratorType Source #
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.
Destructuring the Response
data GetShardIteratorResponse Source #
Represents the output for GetShardIterator.
See: newGetShardIteratorResponse smart constructor.
Constructors
| GetShardIteratorResponse' | |
Fields
| |
Instances
newGetShardIteratorResponse Source #
Create a value of GetShardIteratorResponse with all optional fields omitted.
Use generic-lens or optics to modify other optional fields.
The following record fields are available, with the corresponding lenses provided for backwards compatibility:
$sel:shardIterator:GetShardIteratorResponse', getShardIteratorResponse_shardIterator - 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.
$sel:httpStatus:GetShardIteratorResponse', getShardIteratorResponse_httpStatus - The response's http status code.
Response Lenses
getShardIteratorResponse_shardIterator :: Lens' GetShardIteratorResponse (Maybe Text) Source #
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.
getShardIteratorResponse_httpStatus :: Lens' GetShardIteratorResponse Int Source #
The response's http status code.