Introduction

A batch sink that pushes data from hydrator pipelines into dynamoDb tables.

Use case(s)

• An organization wants to parse the logs generated by a system and want to store the metadata in dynamodb tables.

User Storie(s)

• • User should be able to provide the table name in DynamoDb. 
  • User should be able to provide the primary key of the table. 
  • User should be able to provide the type of primary key (hash or range).
  • The table should be created if it is not already existing. 
  • User should be able to provide the AWS endpoint url for DynamoDb instance.
  • User should be able to provide the AWS region id for DynamoDb instance.
  • User should be able to provide the AWS access id.
  • User should be able to provide the AWS access key.

Plugin Type

•  Batch Source
•  Batch Sink 
•  Real-time Source
•  Real-time Sink
•  Action
•  Post-Run Action
•  Aggregate
•  Join
•  Spark Model
•  Spark Compute

Configurables

This section defines properties that are configurable for this plugin. 

Design / Implementation Tips

• • For Testing purposes tables can be created either using AWS cli or using java code http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/JavaDocumentAPITablesExample.html
  • AWS dynamoDb cli refrence http://docs.aws.amazon.com/cli/latest/reference/dynamodb/
  • Java example for CRUD operations http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/batch-operation-document-api-java.html
  • Please reuse/modify RecordReader, InputFormat classes present here https://github.com/awslabs/emr-dynamodb-connector

Design

DynamoDB Sink JSON format:

{
     "name": "DynamoDb",
     "type": "batchsink",
     "properties": {
         "endpointUrl": "",
         "regionId": "us-east-1",
         "accessKey": "xyz",
         "secretAccessKey": "abc",
         "tableName": "Movies",
         "primaryKeyFields": "Id:N",
         "primaryKeyTypes": "Id:HASH",  
         "readCapacityUnits": "10",
         "throughputwriteCapacityUnits": "10"
    }
}

Approach(s)

1. Dropdown with the list of regions will be provided to user, to select the region for AWS Dynamo DB to connect to. Supported regions are:          
   "us-gov-west-1", "us-east-1", "us-east-2", "us-west-1", "us-west-2", "eu-west-1", "eu-west-2", "eu-central-1", "ap-south-1","ap-southeast-1", "ap-southeast-2", "ap-northeast-1", "ap-northeast-2", "sa-east-1", "cn-north-1", "ca-central-1", "getCurrentRegion".   (Referred from: http://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/
   http://docs.aws.amazon.com/general/latest/gr/rande.html#ddb_region)
   
   
2. If user does not select any region, then default region will be used, i.e. us_west_2.
   
   
3. getCurrentRegion from the list, returns a Region object representing the region the application is running in, when running in EC2. If this method is called from a non-EC2 environment, it will return null.
   
   
4. The plugin will support following CDAP data types in schema:   String, Number(int, long, float, double), Boolean, NULL, Map, List, Array of String and Array of Number, Bytes (will be converted to binary when storing to DynamoDB).
   
   
5. Key value drop-down to take the name of the primary key fields and attribute type. The drop-down will allow following values: String, Number(int, long, float, double), Boolean, NULL, Map, List, Array of String and Array of Number.
   
   
6. Key value drop-down to take the name of the primary key fields and key type. The drop-down will have the following values: "N"(number) and , "S"(string) and "B"(binary - the byte[] value received from the previous stage will be converted to binary when storing the data in DynamoDB).

Properties

• endpointUrl: aws endpoint http://docs.aws.amazon.com/general/latest/gr/rande.html#ddb_region This could be reconstructed using regionId.
• regionId: The region for AWS Dynamo DB to connect to.
• accessKey: Access key for AWS Dynamo DB.
• secretAccessKey: Secret access key for AWS Dynamo DB.
• tableName: The table to read the data from.
• primaryKeyFields: The field name to be used as primary key and its type.
• primaryKeyTypes: Primary key field names and type
• throughput: Intended throughput for DynamoDb.
• readCapacityUnits: The maximum number of strongly consistent reads consumed per second before DynamoDB returns a ThrottlingException. This will be used when creating a new table if the table name specified by the user does not exists.
• writeCapacityUnits: The maximum number of writes consumed per second before DynamoDB returns a ThrottlingException. This will be used when creating a new table if the table name specified by the user does not exists.

Security

• The AWS access keys should be a password field and macros enabled

Limitation(s)

Future Work

Test Case(s)

Sample Pipeline