A Comprehensive Analysis of AWS Athena, AWS S3, and AWS Glue

This topic is discussed in episode #003 of our Cloud & DevOps Pod

A Comprehensive Analysis of AWS Athena, AWS S3, and AWS Glue

In today's data-driven world, organizations are constantly looking for ways to manage and analyze vast amounts of data efficiently and affordably. Amazon Web Services (AWS) offers several tools that can help streamline data storage, querying, and transformation. Among the most widely used are AWS Athena, AWS S3, and AWS Glue. These three services work together seamlessly to form a powerful data processing and analytics ecosystem.

In this blog, we will explore how these services function, their strengths, and when to use them. We'll also provide insights into how they compare to other AWS services and the cost considerations you should be aware of.

AWS S3: The Foundation of Data Storage

At the heart of AWS's data services lies Amazon Simple Storage Service (S3), which is often the starting point for organizations looking to store their data. AWS S3 is a scalable, object-based storage service that allows you to store and retrieve any amount of data at any time. One of its key benefits is its pricing structure, which is based on the amount of data stored and the number of requests made.

S3 is a cornerstone for many AWS services, and it's no surprise that it's commonly used as the main storage location for data lakes. You can ingest raw data from various sources such as RDS, on-premise databases, or external third-party sources into an S3 bucket. From there, you have flexibility regarding how you manage and process that data​(3).

Why S3?

  • Cost-efficiency: AWS S3 offers tiered storage options, allowing you to reduce costs by moving less frequently accessed data to cheaper storage classes like S3 Glacier. With features like Intelligent-Tiering, S3 can automatically move objects to the most cost-effective storage tier based on access patterns​(3).
  • Scalability: S3 is built to scale with your data. Whether you’re storing gigabytes or petabytes of data, S3 can handle it without needing to provision additional resources.
  • Durability: S3 offers a 99.999999999% (11 nines) durability guarantee, making it a reliable option for long-term storage of valuable data​(3).

AWS Athena: Querying Data on S3

Once your data is stored in S3, the next step is often analyzing it, and that’s where AWS Athena comes in. Athena is a serverless, interactive query service that allows you to analyze data stored in S3 using standard SQL. It is built on Presto (or Trino), a distributed SQL query engine, which enables it to process large datasets quickly and efficiently​(3).

Athena charges you based on the amount of data you scan, which means that you only pay when you're running queries. This can make it a cost-effective solution for businesses that don’t need to query their data continuously.

Athena’s Key Benefits:

  • Cost-effectiveness: You only pay when you run queries, and the cost is calculated based on the amount of data scanned. At around $5 per terabyte scanned, Athena is significantly more affordable than traditional databases that require constant uptime and resource allocation​(3).
  • No Infrastructure Management: Athena is serverless, meaning you don’t need to worry about provisioning or managing infrastructure. This eliminates the need for database administration, making it perfect for organizations looking for simplicity.
  • Compatibility: Athena can query data stored in several formats, including JSON, CSV, Parquet, and Avro. It also supports partitioning, which can help improve query performance and reduce costs by narrowing the data scope for specific queries​(3).

However, Athena does come with some limitations. While it’s perfect for exploratory data analysis and reporting, it may not be ideal for use cases requiring real-time processing or for Online Transaction Processing (OLTP) systems that demand low-latency, high-throughput operations. It also takes a few seconds to return query results, which might be fine for analytics but not for high-performance, transaction-heavy environments​(3).

AWS Glue: ETL Made Easy

When working with data, you’ll often need to extract, transform, and load (ETL) it to make it usable for analysis. AWS Glue is AWS’s fully managed ETL service, designed to make it easy to transform data before it’s queried. Glue works by running Spark jobs that can be triggered on-demand or scheduled to run at specified intervals​(3).

Why Use Glue?

  • Managed Service: Glue takes care of provisioning and scaling the underlying infrastructure for your ETL jobs. This reduces the need to manage clusters and resources manually​(3).
  • Integration with S3 and Athena: Glue can read data directly from S3, process it, and then write the transformed data back to S3. This makes it a natural fit for data processing workflows involving Athena. After the ETL job, you can use Athena to query the newly transformed data​(3).
  • Glue Data Catalog: One of Glue's key features is its ability to create a data catalog that serves as a centralized metadata repository for your datasets. This catalog is used by both Glue and Athena to understand the schema and structure of the data you are querying or transforming​(3).

While Glue offers many advantages, particularly for managing complex ETL workflows, it can also become expensive, especially if you’re working with large datasets or running jobs frequently. Glue charges are based on the number of Data Processing Units (DPUs) used, with each DPU consisting of a set amount of CPU and memory. If your ETL job requires substantial resources or runs frequently, costs can quickly add up​(3)​(3).

Comparing Athena, S3, and Glue to Other AWS Services

There are other services within the AWS ecosystem that can complement or replace Athena, S3, and Glue depending on your needs. For example, Amazon Redshift is a popular choice for data warehousing. However, Redshift requires constant resource allocation, and as your dataset grows, it can become significantly more expensive compared to the pay-per-query model of Athena​(3).

Amazon EMR is another service that offers greater control over data processing, allowing you to run Spark, Hadoop, and other frameworks on a managed cluster. However, EMR comes with more complexity, and unless you already have experience managing distributed systems, it may require more effort to set up and maintain​(3).

For organizations that want more control over their environment, EKS (Elastic Kubernetes Service) can be used to manage Spark jobs with greater flexibility. However, this option requires deep expertise in Kubernetes, which could add operational overhead​(3).

Cost Considerations and Optimizing Usage

One of the most important factors in choosing between these services is cost. AWS S3, Athena, and Glue are designed to be cost-effective, but it's still essential to optimize their usage.

  • Partitioning and Compression: To reduce Athena query costs, partition your data based on query patterns and compress your data using formats like Parquet. This reduces the amount of data scanned, which can lead to significant cost savings​(3).
  • Tiers in S3: If you have data that is rarely accessed, store it in lower-cost S3 tiers like Glacier. S3 also offers Intelligent-Tiering, which automatically moves objects to cheaper storage classes based on access frequency​(3).
  • Glue Job Optimizations: For Glue, make sure to optimize your Spark jobs by avoiding excessive idle time, as Glue charges you based on the amount of time the job is running. Use Glue for batch processing, and avoid keeping clusters idle for long periods​(3)​(3).

A Powerful Trio for Data Management

AWS Athena, S3, and Glue together form a powerful and flexible solution for organizations looking to store, process, and analyze their data in a cost-effective way. While each service has its strengths and limitations, they complement each other well, making them a great choice for most data workflows.

If you're exploring AWS for your data needs, consider starting with S3 as your storage layer, using Glue for data transformation, and Athena for querying your data without the need for expensive infrastructure. By leveraging these services wisely, you can optimize both performance and cost, ensuring your data operations run smoothly and efficiently.

Edward Viaene
Published on March 5, 2024