Scan Source: Unbounded Sink: Streaming Append Mode
The Kinesis connector allows for reading data from and writing data into Amazon Kinesis Data Streams (KDS).
In order to use the Kinesis connector the following dependencies are required for both projects using a build automation tool (such as Maven or SBT) and SQL Client with SQL JAR bundles.
Maven dependency | SQL Client JAR |
---|---|
<dependency>
|
Download |
Follow the instructions from the Amazon KDS Developer Guide to set up a Kinesis stream. The following example shows how to create a table backed by a Kinesis data stream:
The following metadata can be exposed as read-only (VIRTUAL
) columns in a table definition.
Key | Data Type | Description |
---|---|---|
timestamp |
TIMESTAMP(3) WITH LOCAL TIME ZONE NOT NULL |
The approximate time when the record was inserted into the stream. |
shard-id |
VARCHAR(128) NOT NULL |
The unique identifier of the shard within the stream from which the record was read. |
sequence-number |
VARCHAR(128) NOT NULL |
The unique identifier of the record within its shard. |
The extended CREATE TABLE
example demonstrates the syntax for exposing these metadata fields:
Option | Required | Default | Type | Description |
---|---|---|---|---|
Common Options | ||||
connector |
required | (none) | String | Specify what connector to use. For Kinesis use 'kinesis' . |
stream |
required | (none) | String | Name of the Kinesis data stream backing this table. |
format |
required | (none) | String | The format used to deserialize and serialize Kinesis data stream records. See Data Type Mapping for details. |
aws.region |
optional | (none) | String | The AWS region where the stream is defined. Either this or aws.endpoint are required. |
aws.endpoint |
optional | (none) | String | The AWS endpoint for Kinesis (derived from the AWS region setting if not set). Either this or aws.region are required. |
Authentication Options | ||||
aws.credentials.provider |
optional | AUTO | String | A credentials provider to use when authenticating against the Kinesis endpoint. See Authentication for details. |
aws.credentials.basic.accesskeyid |
optional | (none) | String | The AWS access key ID to use when setting credentials provider type to BASIC. |
aws.credentials.basic.secretkey |
optional | (none) | String | The AWS secret key to use when setting credentials provider type to BASIC. |
aws.credentials.profile.path |
optional | (none) | String | Optional configuration for profile path if credential provider type is set to be PROFILE. |
aws.credentials.profile.name |
optional | (none) | String | Optional configuration for profile name if credential provider type is set to be PROFILE. |
aws.credentials.role.arn |
optional | (none) | String | The role ARN to use when credential provider type is set to ASSUME_ROLE or WEB_IDENTITY_TOKEN. |
aws.credentials.role.sessionName |
optional | (none) | String | The role session name to use when credential provider type is set to ASSUME_ROLE or WEB_IDENTITY_TOKEN. |
aws.credentials.role.externalId |
optional | (none) | String | The external ID to use when credential provider type is set to ASSUME_ROLE. |
aws.credentials.role.provider |
optional | (none) | String | The credentials provider that provides credentials for assuming the role when credential provider type is set to ASSUME_ROLE. Roles can be nested, so this value can again be set to ASSUME_ROLE |
aws.credentials.webIdentityToken.file |
optional | (none) | String | The absolute path to the web identity token file that should be used if provider type is set to WEB_IDENTITY_TOKEN. |
Source Options | ||||
scan.stream.initpos |
optional | LATEST | String | Initial position to be used when reading from the table. See Start Reading Position for details. |
scan.stream.initpos-timestamp |
optional | (none) | String | The initial timestamp to start reading Kinesis stream from (when scan.stream.initpos is AT_TIMESTAMP). See Start Reading Position for details. |
scan.stream.initpos-timestamp-format |
optional | yyyy-MM-dd'T'HH:mm:ss.SSSXXX | String | The date format of initial timestamp to start reading Kinesis stream from (when scan.stream.initpos is AT_TIMESTAMP). See Start Reading Position for details. |
scan.stream.recordpublisher |
optional | POLLING | String | The RecordPublisher type to use for sources. See Enhanced Fan-Out for details. |
scan.stream.efo.consumername |
optional | (none) | String | The name of the EFO consumer to register with KDS. See Enhanced Fan-Out for details. |
scan.stream.efo.registration |
optional | LAZY | String | Determine how and when consumer de-/registration is performed (LAZY|EAGER|NONE). See Enhanced Fan-Out for details. |
scan.stream.efo.consumerarn |
optional | (none) | String | The prefix of consumer ARN for a given stream. See Enhanced Fan-Out for details. |
scan.stream.efo.http-client.max-concurrency |
optional | 10000 | Integer | Maximum number of allowed concurrent requests for the EFO client. See Enhanced Fan-Out for details. |
scan.stream.describe.maxretries |
optional | 50 | Integer | The maximum number of describeStream attempts if we get a recoverable exception. |
scan.stream.describe.backoff.base |
optional | 2000 | Long | The base backoff time (in milliseconds) between each describeStream attempt (for consuming from DynamoDB streams). |
scan.stream.describe.backoff.max |
optional | 5000 | Long | The maximum backoff time (in milliseconds) between each describeStream attempt (for consuming from DynamoDB streams). |
scan.stream.describe.backoff.expconst |
optional | 1.5 | Double | The power constant for exponential backoff between each describeStream attempt (for consuming from DynamoDB streams). |
scan.list.shards.maxretries |
optional | 10 | Integer | The maximum number of listShards attempts if we get a recoverable exception. |
scan.list.shards.backoff.base |
optional | 1000 | Long | The base backoff time (in milliseconds) between each listShards attempt. |
scan.list.shards.backoff.max |
optional | 5000 | Long | The maximum backoff time (in milliseconds) between each listShards attempt. |
scan.list.shards.backoff.expconst |
optional | 1.5 | Double | The power constant for exponential backoff between each listShards attempt. |
scan.stream.describestreamconsumer.maxretries |
optional | 50 | Integer | The maximum number of describeStreamConsumer attempts if we get a recoverable exception. |
scan.stream.describestreamconsumer.backoff.base |
optional | 2000 | Long | The base backoff time (in milliseconds) between each describeStreamConsumer attempt. |
scan.stream.describestreamconsumer.backoff.max |
optional | 5000 | Long | The maximum backoff time (in milliseconds) between each describeStreamConsumer attempt. |
scan.stream.describestreamconsumer.backoff.expconst |
optional | 1.5 | Double | The power constant for exponential backoff between each describeStreamConsumer attempt. |
scan.stream.registerstreamconsumer.maxretries |
optional | 10 | Integer | The maximum number of registerStream attempts if we get a recoverable exception. |
scan.stream.registerstreamconsumer.timeout |
optional | 60 | Integer | The maximum time in seconds to wait for a stream consumer to become active before giving up. |
scan.stream.registerstreamconsumer.backoff.base |
optional | 500 | Long | The base backoff time (in milliseconds) between each registerStream attempt. |
scan.stream.registerstreamconsumer.backoff.max |
optional | 2000 | Long | The maximum backoff time (in milliseconds) between each registerStream attempt. |
scan.stream.registerstreamconsumer.backoff.expconst |
optional | 1.5 | Double | The power constant for exponential backoff between each registerStream attempt. |
scan.stream.deregisterstreamconsumer.maxretries |
optional | 10 | Integer | The maximum number of deregisterStream attempts if we get a recoverable exception. |
scan.stream.deregisterstreamconsumer.timeout |
optional | 60 | Integer | The maximum time in seconds to wait for a stream consumer to deregister before giving up. |
scan.stream.deregisterstreamconsumer.backoff.base |
optional | 500 | Long | The base backoff time (in milliseconds) between each deregisterStream attempt. |
scan.stream.deregisterstreamconsumer.backoff.max |
optional | 2000 | Long | The maximum backoff time (in milliseconds) between each deregisterStream attempt. |
scan.stream.deregisterstreamconsumer.backoff.expconst |
optional | 1.5 | Double | The power constant for exponential backoff between each deregisterStream attempt. |
scan.shard.subscribetoshard.maxretries |
optional | 10 | Integer | The maximum number of subscribeToShard attempts if we get a recoverable exception. |
scan.shard.subscribetoshard.backoff.base |
optional | 1000 | Long | The base backoff time (in milliseconds) between each subscribeToShard attempt. |
scan.shard.subscribetoshard.backoff.max |
optional | 2000 | Long | The maximum backoff time (in milliseconds) between each subscribeToShard attempt. |
scan.shard.subscribetoshard.backoff.expconst |
optional | 1.5 | Double | The power constant for exponential backoff between each subscribeToShard attempt. |
scan.shard.getrecords.maxrecordcount |
optional | 10000 | Integer | The maximum number of records to try to get each time we fetch records from a AWS Kinesis shard. |
scan.shard.getrecords.maxretries |
optional | 3 | Integer | The maximum number of getRecords attempts if we get a recoverable exception. |
scan.shard.getrecords.backoff.base |
optional | 300 | Long | The base backoff time (in milliseconds) between getRecords attempts if we get a ProvisionedThroughputExceededException. |
scan.shard.getrecords.backoff.max |
optional | 1000 | Long | The maximum backoff time (in milliseconds) between getRecords attempts if we get a ProvisionedThroughputExceededException. |
scan.shard.getrecords.backoff.expconst |
optional | 1.5 | Double | The power constant for exponential backoff between each getRecords attempt. |
scan.shard.getrecords.intervalmillis |
optional | 200 | Long | The interval (in milliseconds) between each getRecords request to a AWS Kinesis shard in milliseconds. |
scan.shard.getiterator.maxretries |
optional | 3 | Integer | The maximum number of getShardIterator attempts if we get ProvisionedThroughputExceededException. |
scan.shard.getiterator.backoff.base |
optional | 300 | Long | The base backoff time (in milliseconds) between getShardIterator attempts if we get a ProvisionedThroughputExceededException. |
scan.shard.getiterator.backoff.max |
optional | 1000 | Long | The maximum backoff time (in milliseconds) between getShardIterator attempts if we get a ProvisionedThroughputExceededException. |
scan.shard.getiterator.backoff.expconst |
optional | 1.5 | Double | The power constant for exponential backoff between each getShardIterator attempt. |
scan.shard.discovery.intervalmillis |
optional | 10000 | Integer | The interval between each attempt to discover new shards. |
scan.shard.adaptivereads |
optional | false | Boolean | The config to turn on adaptive reads from a shard. See the AdaptivePollingRecordPublisher documentation for details. |
scan.shard.idle.interval |
optional | -1 | Long | The interval (in milliseconds) after which to consider a shard idle for purposes of watermark generation. A positive value will allow the watermark to progress even when some shards don't receive new records. |
scan.watermark.sync.interval |
optional | 30000 | Long | The interval (in milliseconds) for periodically synchronizing the shared watermark state. |
scan.watermark.lookahead.millis |
optional | 0 | Long | The maximum delta (in milliseconds) allowed for the reader to advance ahead of the shared global watermark. |
scan.watermark.sync.queue.capacity |
optional | 100 | Integer | The maximum number of records that will be buffered before suspending consumption of a shard. |
Sink Options | ||||
sink.partitioner |
optional | random or row-based | String | Optional output partitioning from Flink's partitions into Kinesis shards. See Sink Partitioning for details. |
sink.partitioner-field-delimiter |
optional | | | String | Optional field delimiter for a fields-based partitioner derived from a PARTITION BY clause. See Sink Partitioning for details. |
sink.producer.* |
optional | (none) |
Sink options for the KinesisProducer .
Suffix names must match the KinesisProducerConfiguration setters in lower-case hyphenated style (for example, sink.producer.collection-max-count or sink.producer.aggregation-max-count ).
The transformed action keys are passed to the sink.producer.* to KinesisProducerConfigurations#fromProperties.
Note that some of the defaults are overwritten by KinesisConfigUtil .
|
Make sure to create an appropriate IAM policy to allow reading from / writing to the Kinesis data streams.
Depending on your deployment you would choose a different Credentials Provider to allow access to Kinesis.
By default, the AUTO
Credentials Provider is used.
If the access key ID and secret key are set in the deployment configuration, this results in using the BASIC
provider.
A specific AWSCredentialsProvider can be optionally set using the aws.credentials.provider
setting.
Supported values are:
AUTO
- Use the default AWS Credentials Provider chain that searches for credentials in the following order: ENV_VARS
, SYS_PROPS
, WEB_IDENTITY_TOKEN
, PROFILE
, and EC2/ECS credentials provider.BASIC
- Use access key ID and secret key supplied as configuration.ENV_VAR
- Use AWS_ACCESS_KEY_ID
& AWS_SECRET_ACCESS_KEY
environment variables.SYS_PROP
- Use Java system properties aws.accessKeyId
and aws.secretKey
.PROFILE
- Use an AWS credentials profile to create the AWS credentials.ASSUME_ROLE
- Create AWS credentials by assuming a role. The credentials for assuming the role must be supplied.WEB_IDENTITY_TOKEN
- Create AWS credentials by assuming a role using Web Identity Token.You can configure table sources to start reading a table-backing Kinesis data stream from a specific position through the scan.stream.initpos
option.
Available values are:
LATEST
: read shards starting from the latest record.TRIM_HORIZON
: read shards starting from the earliest record possible (data may be trimmed by Kinesis depending on the current retention settings of the backing stream).AT_TIMESTAMP
: read shards starting from a specified timestamp. The timestamp value should be specified through the scan.stream.initpos-timestamp
in one of the following formats:
1459799926.480
).SimpleDateFormat
specified at scan.stream.initpos-timestamp-format
.
If a user does not define a format, the default pattern will be yyyy-MM-dd'T'HH:mm:ss.SSSXXX
.
For example, timestamp value is 2016-04-04
and user-defined format is yyyy-MM-dd
, or timestamp value is 2016-04-04T19:58:46.480-00:00
and a user-defined format is not provided.Kinesis data streams consist of one or more shards, and the sink.partitioner
option allows you to control how records written into a multi-shard Kinesis-backed table will be partitioned between its shards.
Valid values are:
fixed
: Kinesis PartitionKey
values derived from the Flink subtask index, so each Flink partition ends up in at most one Kinesis partition (assuming that no re-sharding takes place at runtime).random
: Kinesis PartitionKey
values are assigned randomly. This is the default value for tables not defined with a PARTITION BY
clause.FixedKinesisPartitioner
subclass: e.g. 'org.mycompany.MyPartitioner'
.Note Records written into tables defining a PARTITION BY
clause will always be partitioned based on a concatenated projection of the PARTITION BY
fields.
In this case, the sink.partitioner
field cannot be used to modify this behavior (attempting to do this results in a configuration error).
You can, however, use the sink.partitioner-field-delimiter
option to set the delimiter of field values in the concatenated PartitionKey string (an empty string is also a valid delimiter).
Enhanced Fan-Out (EFO) increases the maximum number of concurrent consumers per Kinesis data stream. Without EFO, all concurrent Kinesis consumers share a single read quota per shard. Using EFO, each consumer gets a distinct dedicated read quota per shard, allowing read throughput to scale with the number of consumers.
Note Using EFO will incur additional cost.
You can enable and configure EFO with the following properties:
scan.stream.recordpublisher
: Determines whether to use EFO
or POLLING
.scan.stream.efo.consumername
: A name to identify the consumer when the above value is EFO
.scan.stream.efo.registration
: Strategy for (de-)registration of EFO
consumers with the name given by the scan.stream.efo.consumername
value. Valid strategies are:
LAZY
(default): Stream consumers are registered when the Flink job starts running.
If the stream consumer already exists, it will be reused.
This is the preferred strategy for the majority of applications.
However, jobs with parallelism greater than 1 will result in tasks competing to register and acquire the stream consumer ARN.
For jobs with very large parallelism this can result in an increased start-up time.
The describe operation has a limit of 20 transactions per second,
this means application startup time will increase by roughly parallelism/20 seconds
.EAGER
: Stream consumers are registered in the FlinkKinesisConsumer
constructor.
If the stream consumer already exists, it will be reused.
This will result in registration occurring when the job is constructed,
either on the Flink Job Manager or client environment submitting the job.
Using this strategy results in a single thread registering and retrieving the stream consumer ARN,
reducing startup time over LAZY
(with large parallelism).
However, consider that the client environment will require access to the AWS services.NONE
: Stream consumer registration is not performed by FlinkKinesisConsumer
.
Registration must be performed externally using the AWS CLI or SDK
to invoke RegisterStreamConsumer.
Stream consumer ARNs should be provided to the job via the consumer configuration.scan.stream.efo.consumerarn.<stream-name>
: ARNs identifying externally registered ARN-consumers (substitute <stream-name>
with the name of your stream in the parameter name).
Use this if you choose to use NONE
as a scan.stream.efo.registration
strategy.Note For a given Kinesis data stream, each EFO consumer must have a unique name. However, consumer names do not have to be unique across data streams. Reusing a consumer name will result in existing subscriptions being terminated.
Note With the LAZY
strategy, stream consumers are de-registered when the job is shutdown gracefully.
In the event that a job terminates within executing the shutdown hooks, stream consumers will remain active.
In this situation the stream consumers will be gracefully reused when the application restarts.
With the NONE
and EAGER
strategies, stream consumer de-registration is not performed by FlinkKinesisConsumer
.
Kinesis stores records as Base64-encoded binary data objects, so it doesn’t have a notion of internal record structure.
Instead, Kinesis records are deserialized and serialized by formats, e.g. ‘avro’, ‘csv’, or ‘json’.
To determine the data type of the messages in your Kinesis-backed tables, pick a suitable Flink format with the format
keyword.
Please refer to the Formats pages for more details.