get_records
¶
get_records(
shard_iterator: ShardIterator,
*,
config_overrides: Optional[KinesisClientConfig] = None,
limit: Optional[GetRecordsInputLimit] = None,
stream_arn: Optional[StreamARN] = None,
stream_id: Optional[StreamId] = None,
dry_run: Optional[BooleanObject] = None,
) -> GetRecordsOutput
Gets data records from a Kinesis data stream's shard.
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.
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. It might take multiple calls to get to a portion of the shard that contains records.
You can scale by provisioning multiple shards per stream while considering service limits (for more information, see Amazon Kinesis Data Streams Limits in the Amazon Kinesis Data Streams Developer Guide). 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. 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 1 MiB in size by default. Amazon Kinesis Data Streams supports large records up to 10 MiB in size, but the average throughput for your stream cannot exceed 1 MiB per second. For more information about how large records are handled, see Large records. Each shard can read up to 2 MiB per second. You can ensure that your calls don't exceed the maximum supported size or throughput by using the Limit parameter to specify the maximum number of records that GetRecords can return. Consider your average record size when determining this limit. The maximum number of records that can be returned per call is 10,000.
The size of the data returned by GetRecords varies depending on the utilization of the shard. It is recommended that consumer applications retrieve records via the GetRecords command using the 5 TPS limit to remain caught up. Retrieving records less frequently can lead to consumer applications falling behind. The maximum size of data that GetRecords can return is 10 MiB. If a call returns this amount of data, subsequent calls made within the next 5 seconds throw ProvisionedThroughputExceededException. If there is insufficient provisioned throughput on the stream, subsequent calls made within the next 1 second throw ProvisionedThroughputExceededException. GetRecords doesn't return any data when it throws an exception. For this reason, we recommend that you wait 1 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, you can use the MillisBehindLatest response attribute. You can also monitor the stream using CloudWatch metrics and other mechanisms (see Monitoring in the Amazon Kinesis Data Streams Developer Guide).
Each Amazon Kinesis record includes a value, ApproximateArrivalTimestamp, that is set when a stream successfully receives and stores a record. This is commonly referred to as a server-side time stamp, whereas a client-side time stamp is set when a data producer creates or sends the record to a stream (a data producer is any data source putting data records into a stream, for example with PutRecords). The time stamp has millisecond precision. There are no guarantees about the time stamp accuracy, or that the time stamp is always increasing. For example, records in a shard or across a stream might have time stamps that are out of order.
This operation has a limit of five transactions per second per shard.
Parameters:
-
shard_iterator(ShardIterator) –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.
-
limit(Optional[GetRecordsInputLimit], default:None) –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. The default value is 10,000. -
stream_arn(Optional[StreamARN], default:None) –The ARN of the stream.
-
stream_id(Optional[StreamId], default:None) –Not Implemented. Reserved for future use.
-
dry_run(Optional[BooleanObject], default:None) –Checks if your request will succeed.
DryRunis an optional parameter.
Raises:
-
AccessDeniedException–Specifies that you do not have the permissions required to perform this operation.
-
DryRunOperationException–The request was rejected because the DryRun parameter was specified.
-
ExpiredIteratorException–The provided iterator exceeds the maximum age allowed.
-
InternalFailureException–The processing of the request failed because of an unknown error, exception, or failure.
-
InvalidArgumentException–A specified parameter exceeds its restrictions, is not supported, or can't be used. For more information, see the returned message.
-
KMSAccessDeniedException–The ciphertext references a key that doesn't exist or that you don't have access to.
-
KMSDisabledException–The request was rejected because the specified customer master key (CMK) isn't enabled.
-
KMSInvalidStateException–The request was rejected because the state of the specified resource isn't valid for this request. For more information, see How Key State Affects Use of a Customer Master Key in the Amazon Web Services Key Management Service Developer Guide.
-
KMSNotFoundException–The request was rejected because the specified entity or resource can't be found.
-
KMSOptInRequired–The Amazon Web Services access key ID needs a subscription for the service.
-
KMSThrottlingException–The request was denied due to request throttling. For more information about throttling, see Limits in the Amazon Web Services Key Management Service Developer Guide.
-
ProvisionedThroughputExceededException–The request rate for the stream is too high, or the requested data is too large for the available throughput. Reduce the frequency or size of your requests. For more information, see Streams Limits in the Amazon Kinesis Data Streams Developer Guide, and Error Retries and Exponential Backoff in Amazon Web Services in the Amazon Web Services General Reference.
-
ResourceNotFoundException–The requested resource could not be found. The stream might not be specified correctly.
-
UnknownServiceError–The service returned an error code this client does not model.
Source code in docs_src/capo_kinesis/_services/kinesis.py
1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 | |