Introduction

A batch source that ingests data from dynamodb into hydrator pipelines.

Use case(s)

• For an organization all the spam emails are being dumped to dynamodb table. As a data scientist I want to train my machine learning models in hydrator pipelines based on the data from the dynamodb tables.
  
  

User Storie(s)

• User should be able to provide the table name in DynamoDb.
• 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 throughput for DynamoDb instance. (Dynamo db charges are incurred based on throughput and user should be able to control the throughput)
• 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
• Java Example for working with queries http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/QueryingJavaDocumentAPI.html
• Please reuse/modify RecordReader, InputFormat classes present here https://github.com/awslabs/emr-dynamodb-connector

Design

We will provide dropdown with the list of supported regions to user, to select the region for AWS Dynamo DB to connect to.

Dynamo Db JSON Format:

{

  "name": "DynamoDb",

  "type": "batchsource",

    "properties": {

                  "accessKey": "xyz",

                  "secretAccessKey": "abc",

                  "regionId": "us-east-1",

                  "endpointUrl": "localhost:8000",

                  "tableName": "Movies",

                  "throughput": "10",

                  "query": "ID = :v_IDyear= 1985",

                  "queryArgumentsMapfilterQuery": ":v_Id=198rating"

                  "partitionKey": "Id",

                  "sortKey": "salary"

    }

}

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. User will provide the complete query(fields and its value) through “Query” widget, that will be used to fetch the data. For example: year = 1985 and rating > 5
   
   
5. If there is any filter query required to fetch the data, it can be provided through “Filter Query” widget.

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.
• throughput: Intended throughput for AWS Dynamo DB.
• query: The query that will fetch the data from table.queryArgumentsMap
• : Comma separated list of arguments identifier specified in "Query" along with its value. Key and value are separated by equality operatorfilterQuery: Query that will be used to filter the fetched data, before returning the final results.
• partitionKey: Partition key, that will be used to fetch the data from table.
• sortKey: Sort Key, that will be used to sort/refine the fetched data from table.

Security

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

Limitation(s)

Future Work

Test Case(s)

Sample Pipeline