The DynamoDB Import Export Tool is designed to perform parallel scans on the source table, store scan results in a queue, then consume the queue by writing the items asynchronously to a destination table.

• Maven
• JRE 1.7+
• Pre-existing source and destination DynamoDB tables

1. Build the library:

    mvn install

2. This produces the target jar in the target/ directory, to start the replication process:

java -jar dynamodb-import-export-tool.jar

--destinationEndpoint <destination_endpoint> // the DynamoDB endpoint where the destination table is located.

--destinationTable <destination_table> // the destination table to write to.

--sourceEndpoint <source_endpoint> // the endpoint where the source table is located.

--sourceTable <source_table>// the source table to read from.

--readThroughputRatio <ratio_in_decimal> // the ratio of read throughput to consume from the source table.

--writeThroughputRatio <ratio_in_decimal> // the ratio of write throughput to consume from the destination table.

--maxWriteThreads // (Optional, default=128 * Available_Processors) Maximum number of write threads to create.

--totalSections // (Optional, default=1) Total number of sections to split the bootstrap into. Each application will only scan and write one section.

--section // (Optional, default=0) section to read and write. Only will scan this one section of all sections, [0...totalSections-1].

--consistentScan // (Optional, default=false) indicates whether consistent scan should be used when reading from the source table.

NOTE: To split the replication process across multiple machines, simply use the totalSections & section command line arguments, where each machine will run one section out of [0 ... totalSections-1].

The below example will read from "mySourceTable" at 100 reads per second, using 4 threads. And it will write to "myDestinationTable" at 50 writes per second, using 8 threads. Both tables are located at "dynamodb.us-west-1.amazonaws.com". (to transfer to a different region, create 2 AmazonDynamoDBClients with different endpoints to pass into the DynamoDBBootstrapWorker and the DynamoDBConsumer.

AmazonDynamoDBClient client = new AmazonDynamoDBClient(new ProfileCredentialsProvider());
client.setEndpoint("dynamodb.us-west-1.amazonaws.com");
DynamoDBBootstrapWorker worker = null;
try {
    // 100.0 read operations per second. 4 threads to scan the table.
    worker = new DynamoDBBootstrapWorker(client,
                100.0, "mySourceTable", 4);
} catch (NullReadCapacityException e) {
    LOGGER.error("The DynamoDB source table returned a null read capacity.", e);
    System.exit(1);
}
 // 50.0 write operations per second. 8 threads to scan the table.
DynamoDBConsumer consumer = new DynamoDBConsumer(client, "myDestinationTable", 50.0, Executors.newFixedThreadPool(8));
try {
    worker.pipe(consumer);
} catch (ExecutionException e) {
    LOGGER.error("Encountered exception when executing transfer.", e);
    System.exit(1);
} catch (InterruptedException e){
    LOGGER.error("Interrupted when executing transfer.", e);
    System.exit(1);
}

The below example will read from a DynamoDB table and export to an array blocking queue. This is useful for when another application would like to consume the DynamoDB entries but does not have a setup application for it. They can just retrieve the queue (consumer.getQueue()) and then continually pop() from it to then process the new entries.

AmazonDynamoDBClient client = new AmazonDynamoDBClient(new ProfileCredentialsProvider());
client.setEndpoint("dynamodb.us-west-1.amazonaws.com");
DynamoDBBootstrapWorker worker = null;
try {
    // 100.0 read operations per second. 4 threads to scan the table.
    worker = new DynamoDBBootstrapWorker(client,
                100.0, "mySourceTable", 4);
} catch (NullReadCapacityException e) {
    LOGGER.error("The DynamoDB source table returned a null read capacity.", e);
    System.exit(1);
}
BlockingQueueConsumer consumer = new BlockingQueueConsumer(8);
try {
    worker.pipe(consumer);
} catch (ExecutionException e) {
    LOGGER.error("Encountered exception when executing transfer.", e);
    System.exit(1);
} catch (InterruptedException e){
    LOGGER.error("Interrupted when executing transfer.", e);
    System.exit(1);
}