Copyright | (c) 2013-2018 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 |
Language | Haskell2010 |
Network.AWS.Kinesis.MergeShards
Description
Merges two adjacent shards in a Kinesis data 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 Data Streams 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 Data Streams immediately returns a response and sets the StreamStatus
to UPDATING
. After the operation is completed, Kinesis Data Streams 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 receive a LimitExceededException
.
MergeShards
has a limit of five transactions per second per account.
Creating a Request
Arguments
:: Text | |
-> Text | |
-> Text | |
-> MergeShards |
Creates a value of MergeShards
with the minimum fields required to make a request.
Use one of the following lenses to modify other fields as desired:
msStreamName
- The name of the stream for the merge.msShardToMerge
- The shard ID of the shard to combine with the adjacent shard for the merge.msAdjacentShardToMerge
- The shard ID of the adjacent shard for the merge.
data MergeShards Source #
Represents the input for MergeShards
.
See: mergeShards
smart constructor.
Instances
Request Lenses
msStreamName :: Lens' MergeShards Text Source #
The name of the stream for the merge.
msShardToMerge :: Lens' MergeShards Text Source #
The shard ID of the shard to combine with the adjacent shard for the merge.
msAdjacentShardToMerge :: Lens' MergeShards Text Source #
The shard ID of the adjacent shard for the merge.
Destructuring the Response
mergeShardsResponse :: MergeShardsResponse Source #
Creates a value of MergeShardsResponse
with the minimum fields required to make a request.
data MergeShardsResponse Source #
See: mergeShardsResponse
smart constructor.