Athena-Express: Simplifying SQL queries on Amazon Athena

As published on the official AWS Partner Network Blog

Synopsis

Athena-Express can simplify executing SQL queries in Amazon Athena AND fetching cleaned-up JSON results in the same synchronous call - well suited for web applications.

Example:

Amazon Athena Background

Amazon Athena, launched at AWS re:Invent 2016, made it easier to analyze data in Amazon S3 using standard SQL. Under the covers, it uses Presto, which is an opensource SQL engine developed by Facebook in 2012 to query their 300 Petabyte data warehouse. It's incredibly powerful!

Amazon Athena combines the strength of Presto with serverless & self-managed capabilities of AWS. By simply pointing Athena to your data in Amazon S3, one could start querying using standard SQL. Most results are delivered within seconds and there’s no need for complex ETL jobs to prepare your data for analysis. This makes it easy for anyone with SQL skills to quickly analyze large-scale datasets.

How athena-express simplifies using Amazon Athena

athena-express simplifies integrating Amazon Athena with any Node.JS application - running as a standalone application or as a Lambda function. As a wrapper on AWS SDK, Athena-Express bundles the following steps listed on the official AWS Documentation:

1. Initiates a query execution
2. Keeps checking until the query has finished executing
3. Fetches the results of the query execution from Amazon S3

And as added features

4. Formats the results into a clean, user-friendly JSON array
5. Handles specific Athena errors by recursively retrying for ThrottlingException, NetworkingError, and TooManyRequestsException
6. Provides optional helpful stats including cost per query in USD

Integrating with Amazon Athena without athena-express would require you to identify the appropriate API methods in the AWS SDK, stich them together sequentially, and then build out an error handling & retry mechanism for each of those methods.

athena-express can help you save time & effort in setting up this integration so that you can focus on core application development.

How is athena-express being used?

The most common use case is integrating a web front-end with Amazon Athena using athena-express as a backend. This backend could be any Node.JS application including AWS Lambda.

Here is an example using AWS Lambda:

This architecture has a web front-end that invokes an API endpoint hosted on Amazon API Gateway by passing a query request. The query request can be as simple as SELECT * FROM movies LIMIT 3

This API Gateway then triggers a Lambda function that has the athena-express library imported.

Setup

Prerequisites

• You will need either an IAM Role (if you're running athena-express on AWS Lambda or AWS EC2) OR an IAM User with accessKeyId and secretAccessKey (if you're running athena-express on a standalone NodeJS application)
• This IAM role/user must have AmazonAthenaFullAccess and AmazonS3FullAccess policies attached
  • Note: As an alternative to granting AmazonS3FullAccess you could granularize and limit write access to a specific bucket. Just specify this bucket name during athena-express initialization

Configuration

• athena-express needs an AWS SDK object created with relevant permissions as mentioned in the prerequisites above.
• This AWS object is passed within the constructor so that it can invoke Amazon Athena SDK. It's up to you how you create this aws object. Here are 4 options:
  1. Create an aws object by explicitly passing in the accessKeyId and secretAccessKey generated in prerequisites

   const aws = require("aws-sdk");
   const awsCredentials = {
       region: "YOUR_AWS_REGION",
   	accessKeyId: "YOUR_AWS_ACCESS_KEY_ID",
   	secretAccessKey: "YOUR_AWS_SECRET_ACCESS_KEY"
   };
   aws.config.update(awsCredentials);
  
   const athenaExpressConfig = { aws }; //configuring athena-express with aws sdk object
   const athenaExpress = new AthenaExpress(athenaExpressConfig);

  2. OR if using Lambda, provide an IAM execution role with AmazonAthenaFullAccess and AmazonS3FullAccess policies attached

   const aws = require("aws-sdk");
   const athenaExpressConfig = { aws }; //configuring athena-express with aws sdk object
   const athenaExpress = new AthenaExpress(athenaExpressConfig);

  3. OR Use instance profiles when using EC2s
  4. OR Use environment variables

Option 1: Simple configuration

• Simple configuration requires only the AWS SDK object to be passed as a parameter to initialize athena-express
• Default values are assumed for all parameter options and athena-express creates a new S3 bucket in your AWS account for Amazon Athena to store the query results in.

const aws = require("aws-sdk");

const athenaExpressConfig = { aws }; //simple configuration with just an aws sdk object

//Initializing athena-express
const athenaExpress = new AthenaExpress(athenaExpressConfig);

Option 2: Advance configuration

• Besides the aws sdk paramater that is required, you can add any of the following optional parameters below

const aws = require("aws-sdk");

//Advance configuration with all options
const athenaExpressConfig = {
	aws, /* required */
	s3: "STRING_VALUE", /* optional */
	db: "STRING_VALUE", /* optional */
	formatJson: BOOLEAN, /* optional default=true */
	retry: Integer, /* optional default=200 */
	getStats: BOOLEAN, /* optional default=false */
	ignoreEmpty: BOOLEAN, /* optional default=true */
	encryption: OBJECT /* optional */
};

//Initializing AthenaExpress
const athenaExpress = new AthenaExpress(athenaExpressConfig);

Advance config Parameters:

Parameter	Format	Default Value	Description
s3	string	athena-express creates a new bucket for you	S3 bucket name/prefix to store Athena query results
db	string	default	Athena database name that the SQL queries should be executed in. When a db name is specified in the config, you can execute SQL queries without needing to explicitly mention DB name. e.g. athenaExpress.query("SELECT * FROM movies LIMIT 3") as opposed to athenaExpress.query({sql: "SELECT * FROM movies LIMIT 3", db: "moviedb"});
formatJson	boolean	true	Override as false if you rather get the raw unformatted output from S3.
retry	integer	200 milliseconds	Wait interval between re-checking if the specific Athena query has finished executing
getStats	boolean	false	Get stats for your query including data scanned in megabytes, athena execution time in milliseconds, item count, and query cost in USD based on the Athena Pricing Documentation. e.g. {DataScannedInMB: 6, QueryCostInUSD: 0.00004768, EngineExecutionTimeInMillis: 2234, Count: 5,...
ignoreEmpty	boolean	true	Ignore fields with empty values from the final JSON response.
encryption	object	Not included	Encryption configuation example usage: { EncryptionOption: "SSE_KMS", KmsKey: process.env.kmskey}

Usage: Invoking athena-express

Using Promises:

let query = {
	sql: "SELECT elb_name, request_port, request_ip FROM elb_logs LIMIT 3" /* required */,
	db: "sampledb" /* optional. You could specify a database here or in the advance configuration option mentioned above*/
};

athenaExpress
	.query(query)
	.then(results => {
		console.log(results);
	})
	.catch(error => {
		console.log(error);
	});

Using Async/Await:

(async () => {
	let query = {
		sql: "SELECT elb_name, request_port, request_ip FROM elb_logs LIMIT 3" /* required */,
		db: "sampledb" /* optional. You could specify a database here or in the configuration constructor*/
	};

	try {
		let results = await athenaExpress.query(query);
		console.log(results);
	} catch (error) {
		console.log(error);
	}
})();

Full Example

Using standard NodeJS application

"use strict";

const AthenaExpress = require("athena-express"),
	aws = require("aws-sdk"),
	awsCredentials = {
		region: "YOUR_AWS_REGION",
		accessKeyId: "YOUR_AWS_ACCESS_KEY_ID",
		secretAccessKey: "YOUR_AWS_SECRET_ACCESS_KEY"
	};

aws.config.update(awsCredentials);

const athenaExpressConfig = {
	aws,
	s3: "s3://my-bucket-for-storing-athena-results-us-east-1",
	getStats: true
};

const athenaExpress = new AthenaExpress(athenaExpressConfig);

//Invoking a query on Amazon Athena
(async () => {
	let query = {
		sql: "SELECT elb_name, request_port, request_ip FROM elb_logs LIMIT 3",
		db: "sampledb"
	};

	try {
		let results = await athenaExpress.query(query);
		console.log(results);
	} catch (error) {
		console.log(error);
	}
})();

Using AWS Lambda

"use strict";

const AthenaExpress = require("athena-express"),
	aws = require("aws-sdk");

	/* AWS Credentials are not required here 
    /* because the IAM Role assumed by this Lambda 
    /* has the necessary permission to execute Athena queries 
    /* and store the result in Amazon S3 bucket */

const athenaExpressConfig = {
	aws,
	db: "sampledb",
	getStats: true
};
const athenaExpress = new AthenaExpress(athenaExpressConfig);

exports.handler = async (event, context, callback) => {
	const sqlQuery = "SELECT elb_name, request_port, request_ip FROM elb_logs LIMIT 3";

	try {
		let results = await athenaExpress.query(sqlQuery);
		callback(null, results);
	} catch (error) {
		callback(error, null);
	}
};

Results:

More Examples

UTILITY queries - Added in v3.0

Show Tables (single column result)

const results = await athenaExpress.query("SHOW TABLES");
console.log(results);

//Output:
{ Items:
  [ { row: 'default' },
    { row: 'sampledb' } ] }

Describe Table (dual column result)

const results = await athenaExpress.query("DESCRIBE elb_logs");
console.log(results);

//Output:
{ Items:
  [ { request_timestamp: 'string' },
    { elb_name: 'string' },
    { request_ip: 'string' },
    { request_port: 'int' },
    { backend_ip: 'string' },
    { backend_port: 'int' },
    { request_processing_time: 'double' },
    { backend_processing_time: 'double' },
    { client_response_time: 'double' },
    { elb_response_code: 'string' },
    { backend_response_code: 'string' },
    { received_bytes: 'bigint' },
    { sent_bytes: 'bigint' },
    { request_verb: 'string' },
    { url: 'string' },
    { protocol: 'string' },
    { user_agent: 'string' },
    { ssl_cipher: 'string' },
    { ssl_protocol: 'string' } ] }

Contributors

Gary Arora

License

MIT