DynamoDB Stream Component

Available as of Camel 2.7

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

URI Format

aws-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&...

URI Options

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.

Batch Consumer

This component implements the Batch Consumer.

This allows you for instance to know how many messages exists in this batch and for instance let the Aggregator aggregate this number of messages.

Usage

AmazonDynamoDBStreamsClient configuration

You will need to create an instance of AmazonDynamoDBStreamsClient and bind it to the registry

ClientConfiguration clientConfiguration = new ClientConfiguration();
clientConfiguration.setProxyHost("http://myProxyHost");
clientConfiguration.setProxyPort(8080);

Region region = Region.getRegion(Regions.fromName(region));
region.createClient(AmazonDynamoDBStreamsClient.class, null, clientConfiguration);
// the 'null' here is the AWSCredentialsProvider which defaults to an instance of DefaultAWSCredentialsProviderChain

registry.bind("kinesisClient", client);

Providing AWS Credentials

It is recommended that the credentials are obtained by using the DefaultAWSCredentialsProviderChain that is the default when creating a new ClientConfiguration instance, however, a different AWSCredentialsProvider can be specified when calling createClient(...).

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.

Dependencies

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

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

where ${camel-version} must be replaced by the actual version of Camel (2.7 or higher).

• AWS Component