@aws-cdk/aws-kinesisfirehose

Amazon Kinesis Data Firehose Construct Library

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All classes with the Cfn prefix in this module (CFN Resources) are always stable and safe to use.

The APIs of higher level constructs in this module are experimental and under active development. They are subject to non-backward compatible changes or removal in any future version. These are not subject to the Semantic Versioning model and breaking changes will be announced in the release notes. This means that while you may use them, you may need to update your source code when upgrading to a newer version of this package.

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Amazon Kinesis Data Firehose is a service for fully-managed delivery of real-time streaming data to storage services such as Amazon S3, Amazon Redshift, Amazon Elasticsearch, Splunk, or any custom HTTP endpoint or third-party services such as Datadog, Dynatrace, LogicMonitor, MongoDB, New Relic, and Sumo Logic.

Kinesis Data Firehose delivery streams are distinguished from Kinesis data streams in their models of consumtpion. Whereas consumers read from a data stream by actively pulling data from the stream, a delivery stream pushes data to its destination on a regular cadence. This means that data streams are intended to have consumers that do on-demand processing, like AWS Lambda or Amazon EC2. On the other hand, delivery streams are intended to have destinations that are sources for offline processing and analytics, such as Amazon S3 and Amazon Redshift.

This module is part of the AWS Cloud Development Kit project. It allows you to define Kinesis Data Firehose delivery streams.

Defining a Delivery Stream

In order to define a Delivery Stream, you must specify a destination. An S3 bucket can be used as a destination. More supported destinations are covered below.

const bucket = new s3.Bucket(this, 'Bucket');
new firehose.DeliveryStream(this, 'Delivery Stream', {
  destinations: [new destinations.S3Bucket(bucket)],
});

The above example defines the following resources:

• An S3 bucket
• A Kinesis Data Firehose delivery stream with Direct PUT as the source and CloudWatch error logging turned on.
• An IAM role which gives the delivery stream permission to write to the S3 bucket.

Sources

There are two main methods of sourcing input data: Kinesis Data Streams and via a "direct put".

See: Sending Data to a Delivery Stream in the Kinesis Data Firehose Developer Guide.

Kinesis Data Stream

A delivery stream can read directly from a Kinesis data stream as a consumer of the data stream. Configure this behaviour by providing a data stream in the sourceStream property when constructing a delivery stream:

declare const destination: firehose.IDestination;
const sourceStream = new kinesis.Stream(this, 'Source Stream');
new firehose.DeliveryStream(this, 'Delivery Stream', {
  sourceStream: sourceStream,
  destinations: [destination],
});

Direct Put

Data must be provided via "direct put", ie., by using a PutRecord or PutRecordBatch API call. There are a number of ways of doing so, such as:

• Kinesis Agent: a standalone Java application that monitors and delivers files while handling file rotation, checkpointing, and retries. See: Writing to Kinesis Data Firehose Using Kinesis Agent in the Kinesis Data Firehose Developer Guide.
• AWS SDK: a general purpose solution that allows you to deliver data to a delivery stream from anywhere using Java, .NET, Node.js, Python, or Ruby. See: Writing to Kinesis Data Firehose Using the AWS SDK in the Kinesis Data Firehose Developer Guide.
• CloudWatch Logs: subscribe to a log group and receive filtered log events directly into a delivery stream. See: logs-destinations.
• Eventbridge: add an event rule target to send events to a delivery stream based on the rule filtering. See: events-targets.
• SNS: add a subscription to send all notifications from the topic to a delivery stream. See: sns-subscriptions.
• IoT: add an action to an IoT rule to send various IoT information to a delivery stream

Destinations

The following destinations are supported. See kinesisfirehose-destinations for the implementations of these destinations.

S3

Defining a delivery stream with an S3 bucket destination:

declare const bucket: s3.Bucket;
const s3Destination = new destinations.S3Bucket(bucket);

new firehose.DeliveryStream(this, 'Delivery Stream', {
  destinations: [s3Destination],
});

The S3 destination also supports custom dynamic prefixes. prefix will be used for files successfully delivered to S3. errorOutputPrefix will be added to failed records before writing them to S3.

declare const bucket: s3.Bucket;
const s3Destination = new destinations.S3Bucket(bucket, {
  dataOutputPrefix: 'myFirehose/DeliveredYear=!{timestamp:yyyy}/anyMonth/rand=!{firehose:random-string}',
  errorOutputPrefix: 'myFirehoseFailures/!{firehose:error-output-type}/!{timestamp:yyyy}/anyMonth/!{timestamp:dd}',
});

See: Custom S3 Prefixes in the Kinesis Data Firehose Developer Guide.

Server-side Encryption

Enabling server-side encryption (SSE) requires Kinesis Data Firehose to encrypt all data sent to delivery stream when it is stored at rest. This means that data is encrypted before being written to the service's internal storage layer and decrypted after it is received from the internal storage layer. The service manages keys and cryptographic operations so that sources and destinations do not need to, as the data is encrypted and decrypted at the boundaries of the service (ie., before the data is delivered to a destination). By default, delivery streams do not have SSE enabled.

The Key Management Service (KMS) Customer Managed Key (CMK) used for SSE can either be AWS-owned or customer-managed. AWS-owned CMKs are keys that an AWS service (in this case Kinesis Data Firehose) owns and manages for use in multiple AWS accounts. As a customer, you cannot view, use, track, or manage these keys, and you are not charged for their use. On the other hand, customer-managed CMKs are keys that are created and owned within your account and managed entirely by you. As a customer, you are responsible for managing access, rotation, aliases, and deletion for these keys, and you are changed for their use. See: Customer master keys in the KMS Developer Guide.

declare const destination: firehose.IDestination;

// SSE with an AWS-owned CMK
new firehose.DeliveryStream(this, 'Delivery Stream AWS Owned', {
  encryption: firehose.StreamEncryption.AWS_OWNED,
  destinations: [destination],
});
// SSE with an customer-managed CMK that is created automatically by the CDK
new firehose.DeliveryStream(this, 'Delivery Stream Implicit Customer Managed', {
  encryption: firehose.StreamEncryption.CUSTOMER_MANAGED,
  destinations: [destination],
});
// SSE with an customer-managed CMK that is explicitly specified
declare const key: kms.Key;
new firehose.DeliveryStream(this, 'Delivery Stream Explicit Customer Managed', {
  encryptionKey: key,
  destinations: [destination],
});

See: Data Protection in the Kinesis Data Firehose Developer Guide.

Monitoring

Kinesis Data Firehose is integrated with CloudWatch, so you can monitor the performance of your delivery streams via logs and metrics.

Logs

Kinesis Data Firehose will send logs to CloudWatch when data transformation or data delivery fails. The CDK will enable logging by default and create a CloudWatch LogGroup and LogStream for your Delivery Stream.

You can provide a specific log group to specify where the CDK will create the log streams where log events will be sent:

import * as logs from '@aws-cdk/aws-logs';

const logGroup = new logs.LogGroup(this, 'Log Group');
declare const bucket: s3.Bucket;
const destination = new destinations.S3Bucket(bucket, {
  logGroup: logGroup,
});

declare const destination: firehose.IDestination;
new firehose.DeliveryStream(this, 'Delivery Stream', {
  destinations: [destination],
});

Logging can also be disabled:

declare const bucket: s3.Bucket;
const destination = new destinations.S3Bucket(bucket, {
  logging: false,
});
new firehose.DeliveryStream(this, 'Delivery Stream', {
  destinations: [destination],
});

See: Monitoring using CloudWatch Logs in the Kinesis Data Firehose Developer Guide.

Metrics

Kinesis Data Firehose sends metrics to CloudWatch so that you can collect and analyze the performance of the delivery stream, including data delivery, data ingestion, data transformation, format conversion, API usage, encryption, and resource usage. You can then use CloudWatch alarms to alert you, for example, when data freshness (the age of the oldest record in the delivery stream) exceeds the buffering limit (indicating that data is not being delivered to your destination), or when the rate of incoming records exceeds the limit of records per second (indicating data is flowing into your delivery stream faster than it is configured to process).

CDK provides methods for accessing delivery stream metrics with default configuration, such as metricIncomingBytes, and metricIncomingRecords (see IDeliveryStream for a full list). CDK also provides a generic metric method that can be used to produce metric configurations for any metric provided by Kinesis Data Firehose; the configurations are pre-populated with the correct dimensions for the delivery stream.

import * as cloudwatch from '@aws-cdk/aws-cloudwatch';
declare const deliveryStream: firehose.DeliveryStream;

// Alarm that triggers when the per-second average of incoming bytes exceeds 90% of the current service limit
const incomingBytesPercentOfLimit = new cloudwatch.MathExpression({
  expression: 'incomingBytes / 300 / bytePerSecLimit',
  usingMetrics: {
    incomingBytes: deliveryStream.metricIncomingBytes({ statistic: cloudwatch.Statistic.SUM }),
    bytePerSecLimit: deliveryStream.metric('BytesPerSecondLimit'),
  },
});

new cloudwatch.Alarm(this, 'Alarm', {
  metric: incomingBytesPercentOfLimit,
  threshold: 0.9,
  evaluationPeriods: 3,
});

See: Monitoring Using CloudWatch Metrics in the Kinesis Data Firehose Developer Guide.

Compression

Your data can automatically be compressed when it is delivered to S3 as either a final or an intermediary/backup destination. Supported compression formats are: gzip, Snappy, Hadoop-compatible Snappy, and ZIP, except for Redshift destinations, where Snappy (regardless of Hadoop-compatibility) and ZIP are not supported. By default, data is delivered to S3 without compression.

// Compress data delivered to S3 using Snappy
declare const bucket: s3.Bucket;
const s3Destination = new destinations.S3Bucket(bucket, {
  compression: destinations.Compression.SNAPPY,
});
new firehose.DeliveryStream(this, 'Delivery Stream', {
  destinations: [s3Destination],
});

Buffering

Incoming data is buffered before it is delivered to the specified destination. The delivery stream will wait until the amount of incoming data has exceeded some threshold (the "buffer size") or until the time since the last data delivery occurred exceeds some threshold (the "buffer interval"), whichever happens first. You can configure these thresholds based on the capabilities of the destination and your use-case. By default, the buffer size is 5 MiB and the buffer interval is 5 minutes.

// Increase the buffer interval and size to 10 minutes and 8 MiB, respectively
declare const bucket: s3.Bucket;
const destination = new destinations.S3Bucket(bucket, {
  bufferingInterval: Duration.minutes(10),
  bufferingSize: Size.mebibytes(8),
});
new firehose.DeliveryStream(this, 'Delivery Stream', {
  destinations: [destination],
});

See: Data Delivery Frequency in the Kinesis Data Firehose Developer Guide.

Destination Encryption

Your data can be automatically encrypted when it is delivered to S3 as a final or an intermediary/backup destination. Kinesis Data Firehose supports Amazon S3 server-side encryption with AWS Key Management Service (AWS KMS) for encrypting delivered data in Amazon S3. You can choose to not encrypt the data or to encrypt with a key from the list of AWS KMS keys that you own. For more information, see Protecting Data Using Server-Side Encryption with AWS KMS–Managed Keys (SSE-KMS). Data is not encrypted by default.

declare const bucket: s3.Bucket;
declare const key: kms.Key;
const destination = new destinations.S3Bucket(bucket, {
  encryptionKey: key,
});
new firehose.DeliveryStream(this, 'Delivery Stream', {
  destinations: [destination],
});

Backup

A delivery stream can be configured to backup data to S3 that it attempted to deliver to the configured destination. Backed up data can be all the data that the delivery stream attempted to deliver or just data that it failed to deliver (Redshift and S3 destinations can only backup all data). CDK can create a new S3 bucket where it will back up data or you can provide a bucket where data will be backed up. You can also provide a prefix under which your backed-up data will be placed within the bucket. By default, source data is not backed up to S3.

// Enable backup of all source records (to an S3 bucket created by CDK).
declare const bucket: s3.Bucket;
new firehose.DeliveryStream(this, 'Delivery Stream Backup All', {
  destinations: [
    new destinations.S3Bucket(bucket, {
      s3Backup: {
        mode: destinations.BackupMode.ALL,
      },
    }),
  ],
});
// Explicitly provide an S3 bucket to which all source records will be backed up.
declare const backupBucket: s3.Bucket;
new firehose.DeliveryStream(this, 'Delivery Stream Backup All Explicit Bucket', {
  destinations: [
    new destinations.S3Bucket(bucket, {
      s3Backup: {
        bucket: backupBucket,
      },
    }),
  ],
});
// Explicitly provide an S3 prefix under which all source records will be backed up.
new firehose.DeliveryStream(this, 'Delivery Stream Backup All Explicit Prefix', {
  destinations: [
    new destinations.S3Bucket(bucket, {
      s3Backup: {
        mode: destinations.BackupMode.ALL,
        dataOutputPrefix: 'mybackup',
      },
    }),
  ],
});

If any Data Processing or Transformation is configured on your Delivery Stream, the source records will be backed up in their original format.

Data Processing/Transformation

Data can be transformed before being delivered to destinations. There are two types of data processing for delivery streams: record transformation with AWS Lambda, and record format conversion using a schema stored in an AWS Glue table. If both types of data processing are configured, then the Lambda transformation is performed first. By default, no data processing occurs. This construct library currently only supports data transformation with AWS Lambda. See #15501 to track the status of adding support for record format conversion.

Data transformation with AWS Lambda

To transform the data, Kinesis Data Firehose will call a Lambda function that you provide and deliver the data returned in place of the source record. The function must return a result that contains records in a specific format, including the following fields:

• recordId -- the ID of the input record that corresponds the results.
• result -- the status of the transformation of the record: "Ok" (success), "Dropped" (not processed intentionally), or "ProcessingFailed" (not processed due to an error).
• data -- the transformed data, Base64-encoded.

The data is buffered up to 1 minute and up to 3 MiB by default before being sent to the function, but can be configured using bufferInterval and bufferSize in the processor configuration (see: Buffering). If the function invocation fails due to a network timeout or because of hitting an invocation limit, the invocation is retried 3 times by default, but can be configured using retries in the processor configuration.

// Provide a Lambda function that will transform records before delivery, with custom
// buffering and retry configuration
const lambdaFunction = new lambda.Function(this, 'Processor', {
  runtime: lambda.Runtime.NODEJS_12_X,
  handler: 'index.handler',
  code: lambda.Code.fromAsset(path.join(__dirname, 'process-records')),
});
const lambdaProcessor = new firehose.LambdaFunctionProcessor(lambdaFunction, {
  bufferInterval: Duration.minutes(5),
  bufferSize: Size.mebibytes(5),
  retries: 5,
});
declare const bucket: s3.Bucket;
const s3Destination = new destinations.S3Bucket(bucket, {
  processor: lambdaProcessor,
});
new firehose.DeliveryStream(this, 'Delivery Stream', {
  destinations: [s3Destination],
});

Example Lambda data processor performing the identity transformation.

See: Data Transformation in the Kinesis Data Firehose Developer Guide.

Specifying an IAM role

The DeliveryStream class automatically creates IAM service roles with all the minimum necessary permissions for Kinesis Data Firehose to access the resources referenced by your delivery stream. One service role is created for the delivery stream that allows Kinesis Data Firehose to read from a Kinesis data stream (if one is configured as the delivery stream source) and for server-side encryption. Another service role is created for each destination, which gives Kinesis Data Firehose write access to the destination resource, as well as the ability to invoke data transformers and read schemas for record format conversion. If you wish, you may specify your own IAM role for either the delivery stream or the destination service role, or both. It must have the correct trust policy (it must allow Kinesis Data Firehose to assume it) or delivery stream creation or data delivery will fail. Other required permissions to destination resources, encryption keys, etc., will be provided automatically.

// Create service roles for the delivery stream and destination.
// These can be used for other purposes and granted access to different resources.
// They must include the Kinesis Data Firehose service principal in their trust policies.
// Two separate roles are shown below, but the same role can be used for both purposes.
const deliveryStreamRole = new iam.Role(this, 'Delivery Stream Role', {
  assumedBy: new iam.ServicePrincipal('firehose.amazonaws.com'),
});
const destinationRole = new iam.Role(this, 'Destination Role', {
  assumedBy: new iam.ServicePrincipal('firehose.amazonaws.com'),
});

// Specify the roles created above when defining the destination and delivery stream.
declare const bucket: s3.Bucket;
const destination = new destinations.S3Bucket(bucket, { role: destinationRole });
new firehose.DeliveryStream(this, 'Delivery Stream', {
  destinations: [destination],
  role: deliveryStreamRole,
});

See Controlling Access in the Kinesis Data Firehose Developer Guide.

Granting application access to a delivery stream

IAM roles, users or groups which need to be able to work with delivery streams should be granted IAM permissions.

Any object that implements the IGrantable interface (ie., has an associated principal) can be granted permissions to a delivery stream by calling:

• grantPutRecords(principal) - grants the principal the ability to put records onto the delivery stream
• grant(principal, ...actions) - grants the principal permission to a custom set of actions

const lambdaRole = new iam.Role(this, 'Role', {
  assumedBy: new iam.ServicePrincipal('lambda.amazonaws.com'),
});

// Give the role permissions to write data to the delivery stream
declare const deliveryStream: firehose.DeliveryStream;
deliveryStream.grantPutRecords(lambdaRole);

The following write permissions are provided to a service principal by the grantPutRecords() method:

• firehose:PutRecord
• firehose:PutRecordBatch

Granting a delivery stream access to a resource

Conversely to the above, Kinesis Data Firehose requires permissions in order for delivery streams to interact with resources that you own. For example, if an S3 bucket is specified as a destination of a delivery stream, the delivery stream must be granted permissions to put and get objects from the bucket. When using the built-in AWS service destinations found in the @aws-cdk/aws-kinesisfirehose-destinations module, the CDK grants the permissions automatically. However, custom or third-party destinations may require custom permissions. In this case, use the delivery stream as an IGrantable, as follows:

const fn = new lambda.Function(this, 'Function', {
  code: lambda.Code.fromInline('exports.handler = (event) => {}'),
  runtime: lambda.Runtime.NODEJS_14_X,
  handler: 'index.handler',
});

declare const deliveryStream: firehose.DeliveryStream;
fn.grantInvoke(deliveryStream);

Multiple destinations

Though the delivery stream allows specifying an array of destinations, only one destination per delivery stream is currently allowed. This limitation is enforced at CDK synthesis time and will throw an error.