CASE STUDY OF AWS SQS

What is Amazon SQS?

Amazon Simple Queue Service (SQS) is a fully managed message queuing service that enables you to decouple and scale microservices, distributed systems, and server less applications. SQS eliminates the complexity and overhead associated with managing and operating message oriented middleware, and empowers developers to focus on differentiating work. Using SQS, you can send, store, and receive messages between software components at any volume, without losing messages or requiring other services to be available. Get started with SQS in minutes using the AWS console, Command Line Interface or SDK of your choice, and three simple commands.

How does SQS work?

SQS provides an API endpoint to submit messages and another endpoint to read messages from a queue. Each message can only be retrieved once, and you can have many clients submitting messages to and reading messages from a queue at the same time.

The messages that SQS handles can be unformatted strings, XML or JSON. Because SQS guarantees “exactly once” delivery, and because you can concurrently submit messages to and read messages from a given queue, SQS is a good option for integrating multiple independent systems.

You might well be asking: why use SQS if you can have an internal HTTP API for each service? While HTTP APIs are an accessible way to expose software systems to external users, it’s not the most efficient mechanism when it comes to integrating purely internal systems. A messaging queue is more lightweight. In particular, SQS also handles things like automated retries, preserving queue state across multiple availability zones in AWS, and keeping track of expiration timeouts on all messages.

What is SQS used for?

The most common ways to use SQS, and of course other messaging systems, in cloud applications, are:

Decoupling microservices. In a microservice architecture, messages represent one of the easiest ways to set up communication between different parts of the system. If your microservices run in AWS, and especially if those are Serverless services, SQS is a great choice for that aspect of the communication.

Sending tasks between different parts of your system. You don’t have to be running a micro services-oriented application to take advantage of SQS. You can also use it in any kind of application that needs to communicate tasks to other systems.

Distributing workloads from a central node to worker nodes. You can frequently find messaging systems in the flows of distributed large workloads like map-reduce operations. For these kinds of operations, it’s essential to be able to maintain a queue of all the tasks that need to be processed, efficiently distribute the tasks between the machines or functions doing the work, and guarantee that every part of the work is only done once.

Scheduling batch jobs. SQS is a great option for scheduling batch jobs for two reasons. First, it maintains a durable queue of all the scheduled jobs, which means you don’t need to keep track of the job status — you can rely on SQS to pass the jobs through and to handle any retries, should an execution fail and your batch system returns the message to the queue. Second, it integrates with AWS Lambda; if you’re using AWS Lambda to process the batch jobs, SQS automatically launches your Lambda functions once the data is available for them to process.

Benefits of using Amazon SQS

• Security - You control who can send messages to and receive messages from an Amazon SQS queue. Server-side encryption (SSE) lets you transmit sensitive data by protecting the contents of messages in queues using keys managed in AWS Key Management Service (AWS KMS).
• Durability - For the safety of your messages, Amazon SQS stores them on multiple servers. Standard queues support at-least-once message delivery, and FIFO queues support exactly-once message processing.
• Availability - Amazon SQS uses redundant infrastructure to provide highly-concurrent access to messages and high availability for producing and consuming messages.
• Scalability - Amazon SQS can process each buffered request independently, scaling transparently to handle any load increases or spikes without any provisioning instructions.
• Reliability - Amazon SQS locks your messages during processing, so that multiple producers can send and multiple consumers can receive messages at the same time.
• Customization - Your queues don’t have to be exactly alike — for example, you can set a default delay on a queue. You can store the contents of messages larger than 256 KB using Amazon Simple Storage Service (Amazon S3) or Amazon DynamoDB, with Amazon SQS holding a pointer to the Amazon S3 object, or you can split a large message into smaller messages.

USE CASE

redBus is an Indian travel agency that specializes in bus travel throughout India by selling bus tickets throughout the country. Tickets are purchased through the company’s Website or through the Web services of its agents and partners. The company also offers software, on a Software as a Service (SaaS) basis, which gives bus operators the option of handling their own ticketing and managing their own inventories. To date, the company says they have sold over 30 million bus tickets and has more than 1750 bus operators using the software to manage their operations.

The Challenge

The company previously ran its operations from a traditional data center by purchasing and renting its systems and infrastructure. In addition to the expense, several logistical problems evolved from this arrangement. The biggest problem was that the infrastructure could not effectively handle processing fluctuations, which had a negative impact on productivity. Additionally, the procurement of servers or upgrading the server configuration was an extremely time-consuming endeavor. Over time, redBus realized that a better solution was imperative — a solution that offered scalability to handle the company’s processing fluctuations. redBus looked to Amazon Web Services (AWS) for a solution.

Why Amazon Web Services

After testing the AWS solution on a small application for several months, the travel agency determined that it was very workable and convenient. Although redBus was quite enthusiastic about the on-demand instances and variety of instance types, several other features cemented the company’s decision to migrate completely to AWS. These features included the ability to easily manage access to servers through security groups, the easy-to-use, self-service management console, the concept of Elastic IPs, and superior support.

The company has incorporated many of the AWS products into its solution, including Amazon EC2, Elastic load balancing, Amazon RDS, Amazon S3,Amazon EBS, and Amazon CloudWatch.

Charan Padmaraju, Chief Technology Officer believes that “with features like Elastic Load Balancing and multiple availability zones, AWS provides the required infrastructure to build for redundancy and auto-failover. When you incorporate these in your system/application design, you can achieve high reliability and scale.”

The Benefits

Since migrating to AWS, redBus has seen measurable improvements in the bottom line. Padmaraju says, “By scaling up and down dynamically based on the load, we maintain performance as well as minimize cost. With the time savings that the IT and development staffs obtain from the AWS solution, AWS gives us an overall cost benefit of about 30–40%.” He adds, “By hosting at [the AWS Asia Pacific (Singapore) region], redBus.in gained significantly in terms of website performance by way of reduced latency (about 4x). This is a great advantage when the customers are from India.”

Of the many excellent characteristics of AWS, perhaps the most significant to redBus is the ability to “instantly replicate the whole setup on demand for testing by creating and destroying instances on demand for experimentation, thereby reducing the time to market.” Less time to market translates to increased profitability and success.

The travel agency anticipates expanding the AWS solution to include Amazon Simple Notification Service (Amazon SNS) and Amazon Simple Queue Service (Amazon SQS) for monitoring, alerts, and intercommunication. 

“Amazon SQS is an especially good solution for enabling messaging between external applications and our applications,” says Padmaraju.

Since joining forces with AWS, redBus has gained the freedom to experiment on new solutions and applications at minimal cost, increased the efficiency of its operations, and improved its profitability.

Benefits of AWS

• Reduced costs by up to 40%
• Reduced website latency by 4x
• Able to instantly replicate test environments, which in turn reduces time to market