AWS DynamoDB Streams

Since Camel 3.1

Only consumer is supported

The AWS2 DynamoDB Stream component supports receiving messages from Amazon DynamoDB Stream service.

Prerequisites

You must have a valid Amazon Web Services developer account, and be signed up to use Amazon DynamoDB Streams. More information is available at AWS DynamoDB

URI Format

aws2-ddbstream://table-name[?options]

The stream needs to be created prior to it being used.
You can append query options to the URI in the following format, ?options=value&option2=value&…​

Configuring Options

Camel components are configured on two separate levels:

  • component level

  • endpoint level

Configuring Component Options

The component level is the highest level which holds general and common configurations that are inherited by the endpoints. For example a component may have security settings, credentials for authentication, urls for network connection and so forth.

Some components only have a few options, and others may have many. Because components typically have pre configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all.

Configuring components can be done with the Component DSL, in a configuration file (application.properties|yaml), or directly with Java code.

Configuring Endpoint Options

Where you find yourself configuring the most is on endpoints, as endpoints often have many options, which allows you to configure what you need the endpoint to do. The options are also categorized into whether the endpoint is used as consumer (from) or as a producer (to), or used for both.

Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL and DataFormat DSL as a type safe way of configuring endpoints and data formats in Java.

A good practice when configuring options is to use Property Placeholders, which allows to not hardcode urls, port numbers, sensitive information, and other settings. In other words placeholders allows to externalize the configuration from your code, and gives more flexibility and reuse.

The following two sections lists all the options, firstly for the component followed by the endpoint.

Component Options

The AWS DynamoDB Streams component supports 22 options, which are listed below.

Name Description Default Type

bridgeErrorHandler (consumer)

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions (if possible) occurred while the Camel consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. Important: This is only possible if the 3rd party component allows Camel to be alerted if an exception was thrown. Some components handle this internally only, and therefore bridgeErrorHandler is not possible. In other situations we may improve the Camel component to hook into the 3rd party component and make this possible for future releases. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

false

boolean

configuration (consumer)

The component configuration.

Ddb2StreamConfiguration

maxResultsPerRequest (consumer)

Maximum number of records that will be fetched in each poll.

int

overrideEndpoint (consumer)

Set the need for overidding the endpoint. This option needs to be used in combination with uriEndpointOverride option.

false

boolean

region (consumer)

The region in which DDBStreams client needs to work.

Enum values:

  • ap-south-2

  • ap-south-1

  • eu-south-1

  • eu-south-2

  • us-gov-east-1

  • me-central-1

  • il-central-1

  • ca-central-1

  • eu-central-1

  • us-iso-west-1

  • eu-central-2

  • us-west-1

  • us-west-2

  • af-south-1

  • eu-north-1

  • eu-west-3

  • eu-west-2

  • eu-west-1

  • ap-northeast-3

  • ap-northeast-2

  • ap-northeast-1

  • me-south-1

  • sa-east-1

  • ap-east-1

  • cn-north-1

  • us-gov-west-1

  • ap-southeast-1

  • ap-southeast-2

  • us-iso-east-1

  • ap-southeast-3

  • ap-southeast-4

  • us-east-1

  • us-east-2

  • cn-northwest-1

  • us-isob-east-1

  • aws-global

  • aws-cn-global

  • aws-us-gov-global

  • aws-iso-global

  • aws-iso-b-global

String

streamIteratorType (consumer)

Defines where in the DynamoDB stream to start getting records. Note that using FROM_START can cause a significant delay before the stream has caught up to real-time.

Enum values:

  • FROM_LATEST

  • FROM_START

FROM_LATEST

StreamIteratorType

uriEndpointOverride (consumer)

Set the overriding uri endpoint. This option needs to be used in combination with overrideEndpoint option.

String

amazonDynamoDbStreamsClient (consumer (advanced))

Autowired Amazon DynamoDB client to use for all requests for this endpoint.

DynamoDbStreamsClient

autowiredEnabled (advanced)

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

boolean

healthCheckConsumerEnabled (health)

Used for enabling or disabling all consumer based health checks from this component.

true

boolean

healthCheckProducerEnabled (health)

Used for enabling or disabling all producer based health checks from this component. Notice: Camel has by default disabled all producer based health-checks. You can turn on producer checks globally by setting camel.health.producersEnabled=true.

true

boolean

proxyHost (proxy)

To define a proxy host when instantiating the DDBStreams client.

String

proxyPort (proxy)

To define a proxy port when instantiating the DDBStreams client.

Integer

proxyProtocol (proxy)

To define a proxy protocol when instantiating the DDBStreams client.

Enum values:

  • HTTP

  • HTTPS

HTTPS

Protocol

accessKey (security)

Amazon AWS Access Key.

String

profileCredentialsName (security)

If using a profile credentials provider this parameter will set the profile name.

String

secretKey (security)

Amazon AWS Secret Key.

String

sessionToken (security)

Amazon AWS Session Token used when the user needs to assume a IAM role.

String

trustAllCertificates (security)

If we want to trust all certificates in case of overriding the endpoint.

false

boolean

useDefaultCredentialsProvider (security)

Set whether the DynamoDB Streams client should expect to load credentials through a default credentials provider or to expect static credentials to be passed in.

false

boolean

useProfileCredentialsProvider (security)

Set whether the Cloudtrail client should expect to load credentials through a profile credentials provider.

false

boolean

useSessionCredentials (security)

Set whether the DDB Streams client should expect to use Session Credentials. This is useful in situation in which the user needs to assume a IAM role for doing operations in DDB.

false

boolean

Endpoint Options

The AWS DynamoDB Streams endpoint is configured using URI syntax:

aws2-ddbstream:tableName

with the following path and query parameters:

Path Parameters (1 parameters)

Name Description Default Type

tableName (consumer)

Required Name of the dynamodb table.

String

Query Parameters (36 parameters)

Name Description Default Type

maxResultsPerRequest (consumer)

Maximum number of records that will be fetched in each poll.

int

overrideEndpoint (consumer)

Set the need for overidding the endpoint. This option needs to be used in combination with uriEndpointOverride option.

false

boolean

region (consumer)

The region in which DDBStreams client needs to work.

Enum values:

  • ap-south-2

  • ap-south-1

  • eu-south-1

  • eu-south-2

  • us-gov-east-1

  • me-central-1

  • il-central-1

  • ca-central-1

  • eu-central-1

  • us-iso-west-1

  • eu-central-2

  • us-west-1

  • us-west-2

  • af-south-1

  • eu-north-1

  • eu-west-3

  • eu-west-2

  • eu-west-1

  • ap-northeast-3

  • ap-northeast-2

  • ap-northeast-1

  • me-south-1

  • sa-east-1

  • ap-east-1

  • cn-north-1

  • us-gov-west-1

  • ap-southeast-1

  • ap-southeast-2

  • us-iso-east-1

  • ap-southeast-3

  • ap-southeast-4

  • us-east-1

  • us-east-2

  • cn-northwest-1

  • us-isob-east-1

  • aws-global

  • aws-cn-global

  • aws-us-gov-global

  • aws-iso-global

  • aws-iso-b-global

String

sendEmptyMessageWhenIdle (consumer)

If the polling consumer did not poll any files, you can enable this option to send an empty message (no body) instead.

false

boolean

streamIteratorType (consumer)

Defines where in the DynamoDB stream to start getting records. Note that using FROM_START can cause a significant delay before the stream has caught up to real-time.

Enum values:

  • FROM_LATEST

  • FROM_START

FROM_LATEST

StreamIteratorType

uriEndpointOverride (consumer)

Set the overriding uri endpoint. This option needs to be used in combination with overrideEndpoint option.

String

amazonDynamoDbStreamsClient (consumer (advanced))

Autowired Amazon DynamoDB client to use for all requests for this endpoint.

DynamoDbStreamsClient

bridgeErrorHandler (consumer (advanced))

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions (if possible) occurred while the Camel consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. Important: This is only possible if the 3rd party component allows Camel to be alerted if an exception was thrown. Some components handle this internally only, and therefore bridgeErrorHandler is not possible. In other situations we may improve the Camel component to hook into the 3rd party component and make this possible for future releases. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

false

boolean

exceptionHandler (consumer (advanced))

To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this option is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored.

ExceptionHandler

exchangePattern (consumer (advanced))

Sets the exchange pattern when the consumer creates an exchange.

Enum values:

  • InOnly

  • InOut

ExchangePattern

pollStrategy (consumer (advanced))

A pluggable org.apache.camel.PollingConsumerPollingStrategy allowing you to provide your custom implementation to control error handling usually occurred during the poll operation before an Exchange have been created and being routed in Camel.

PollingConsumerPollStrategy

proxyHost (proxy)

To define a proxy host when instantiating the DDBStreams client.

String

proxyPort (proxy)

To define a proxy port when instantiating the DDBStreams client.

Integer

proxyProtocol (proxy)

To define a proxy protocol when instantiating the DDBStreams client.

Enum values:

  • HTTP

  • HTTPS

HTTPS

Protocol

backoffErrorThreshold (scheduler)

The number of subsequent error polls (failed due some error) that should happen before the backoffMultipler should kick-in.

int

backoffIdleThreshold (scheduler)

The number of subsequent idle polls that should happen before the backoffMultipler should kick-in.

int

backoffMultiplier (scheduler)

To let the scheduled polling consumer backoff if there has been a number of subsequent idles/errors in a row. The multiplier is then the number of polls that will be skipped before the next actual attempt is happening again. When this option is in use then backoffIdleThreshold and/or backoffErrorThreshold must also be configured.

int

delay (scheduler)

Milliseconds before the next poll.

500

long

greedy (scheduler)

If greedy is enabled, then the ScheduledPollConsumer will run immediately again, if the previous run polled 1 or more messages.

false

boolean

initialDelay (scheduler)

Milliseconds before the first poll starts.

1000

long

repeatCount (scheduler)

Specifies a maximum limit of number of fires. So if you set it to 1, the scheduler will only fire once. If you set it to 5, it will only fire five times. A value of zero or negative means fire forever.

0

long

runLoggingLevel (scheduler)

The consumer logs a start/complete log line when it polls. This option allows you to configure the logging level for that.

Enum values:

  • TRACE

  • DEBUG

  • INFO

  • WARN

  • ERROR

  • OFF

TRACE

LoggingLevel

scheduledExecutorService (scheduler)

Allows for configuring a custom/shared thread pool to use for the consumer. By default each consumer has its own single threaded thread pool.

ScheduledExecutorService

scheduler (scheduler)

To use a cron scheduler from either camel-spring or camel-quartz component. Use value spring or quartz for built in scheduler.

none

Object

schedulerProperties (scheduler)

To configure additional properties when using a custom scheduler or any of the Quartz, Spring based scheduler.

Map

startScheduler (scheduler)

Whether the scheduler should be auto started.

true

boolean

timeUnit (scheduler)

Time unit for initialDelay and delay options.

Enum values:

  • NANOSECONDS

  • MICROSECONDS

  • MILLISECONDS

  • SECONDS

  • MINUTES

  • HOURS

  • DAYS

MILLISECONDS

TimeUnit

useFixedDelay (scheduler)

Controls if fixed delay or fixed rate is used. See ScheduledExecutorService in JDK for details.

true

boolean

accessKey (security)

Amazon AWS Access Key.

String

profileCredentialsName (security)

If using a profile credentials provider this parameter will set the profile name.

String

secretKey (security)

Amazon AWS Secret Key.

String

sessionToken (security)

Amazon AWS Session Token used when the user needs to assume a IAM role.

String

trustAllCertificates (security)

If we want to trust all certificates in case of overriding the endpoint.

false

boolean

useDefaultCredentialsProvider (security)

Set whether the DynamoDB Streams client should expect to load credentials through a default credentials provider or to expect static credentials to be passed in.

false

boolean

useProfileCredentialsProvider (security)

Set whether the Cloudtrail client should expect to load credentials through a profile credentials provider.

false

boolean

useSessionCredentials (security)

Set whether the DDB Streams client should expect to use Session Credentials. This is useful in situation in which the user needs to assume a IAM role for doing operations in DDB.

false

boolean

Required DynamoDBStream component options

You have to provide the DynamoDbStreamsClient in the Registry with proxies and relevant credentials configured.

Sequence Numbers

You can provide a literal string as the sequence number or provide a bean in the registry. An example of using the bean would be to save your current position in the change feed and restore it on Camel startup.

It is an error to provide a sequence number that is greater than the largest sequence number in the describe-streams result, as this will lead to the AWS call returning an HTTP 400.

Usage

Static credentials, Default Credential Provider and Profile Credentials Provider

You have the possibility of avoiding the usage of explicit static credentials, by specifying the useDefaultCredentialsProvider option and set it to true.

The order of evaluation for Default Credentials Provider is the following:

  • Java system properties - aws.accessKeyId and aws.secretKey

  • Environment variables - AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY.

  • Web Identity Token from AWS STS.

  • The shared credentials and config files.

  • Amazon ECS container credentials - loaded from the Amazon ECS if the environment variable AWS_CONTAINER_CREDENTIALS_RELATIVE_URI is set.

  • Amazon EC2 Instance profile credentials.

You have also the possibility of using Profile Credentials Provider, by specifying the useProfileCredentialsProvider option to true and profileCredentialsName to the profile name.

Only one of static, default and profile credentials could be used at the same time.

For more information about this you can look at AWS credentials documentation

Coping with Downtime

AWS DynamoDB Streams outage of less than 24 hours

The consumer will resume from the last seen sequence number (as implemented for CAMEL-9515), so you should receive a flood of events in quick succession, as long as the outage did not also include DynamoDB itself.

AWS DynamoDB Streams outage of more than 24 hours

Given that AWS only retain 24 hours worth of changes, you will have missed change events no matter what mitigations are in place.

Message Body

The Message body is instance of "software.amazon.awssdk.services.dynamodb.model.Record", for more information about it, have a look at the related javadoc

Dependencies

Maven users will need to add the following dependency to their pom.xml.

pom.xml

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-aws2-ddb</artifactId>
    <version>${camel-version}</version>
</dependency>

where ${camel-version} must be replaced by the actual version of Camel.