Azure Event Hubs and Amazon Kinesis Side by Side

Azure Event Hubs and Amazon Kinesis are two competing cloud services that serve the same purpose – reliably collect and process massive amounts of data with low latency and at low cost. Although both services provide similar functionality, there are significant differences to be aware of when architecting a solution. This article compares various aspects of Azure Event Hubs and Amazon Kinesis and is intended to assist in the software architecture decision-making process.

Key concepts

Amazon Kinesis streams use shards as the base throughput units. Each shard provides a capacity of 1MB/sec data input and 2MB/sec data output, supports up to 1,000 PUT records and up to 5 read transactions per second. The default shard limit depends on a region and is either 25 or 50 shards per region but you can request an increase. There is no upper limit to the number of shards in a stream or account.

Azure Event Hubs stream throughput capacity is controlled by throughput units. One throughput unit includes up to 1MB/sec ingress, up to 2MB/sec egress, and supports 1,000 events per second. Event Hubs also introduce a concept of partitions – a data organization mechanism designed to support multiple concurrent readers. A single partition has a maximum scale of one throughput unit. There’s a default limit of 20 throughput units per Azure account and 32 partitions per Event Hub but both limits can be increased by request.

Data input

Amazon Kinesis API uses HTTPS protocol for all operations. Every put request must be signed using an access key. You can control the level of access to Amazon Kinesis resources using AWS Identity and Access Management (IAM). IAM policies that only allow write operations to specific streams can be used to add data records. Data producers can also use the Amazon Kinesis Producer Library (KPL) to simplify producer application development. The maximum size of a data blob (the data payload before Base64-encoding) is 1MB.

Azure Event Hubs support HTTPS and AMQP 1.0 protocols for event publishing. Event publishers use Shared Access Signature (SAS) tokens for authentication. SAS tokens for event publishers can be created with send-only privileges on a specific Event Hub. .NET developers can take advantage of the EventHubClient for publishing events to Event Hubs and Apache Qpid project can be used for sending messages over AMQP from a variety of platforms and languages. You can send up to 256KB of event data in a single request. Publisher policies is a distinctive feature of Azure Event Hubs that is designed to facilitate large numbers of independent event producers.

Data processing

Amazon Kinesis consumer applications can read data from streams using either Amazon Kinesis API or Amazon Kinesis Client Library (KCL). Amazon Kinesis Client Library (KCL) makes it easier to build robust applications that read and process stream data by handling complexities typically associated with distributed stream processing. Amazon Kinesis Connector Library helps you integrate Amazon Kinesis with other AWS services and third-party tools and provides connectors to Amazon DynamoDB, Amazon Redshift, Amazon S3, and Elasticsearch. Amazon Kinesis Storm Spout library helps Java developers integrate Amazon Kinesis with Apache Storm.

Azure Event Hubs consumers connect via the AMQP 1.0 session, in which events are delivered as they become available. Consumer groups allow multiple consuming applications to read the same stream independently at their own pace. You can create up 20 consumer groups per Event Hub. The EventProcessorHost class can significantly simplify distributed partition processing for .NET clients. Azure Steam Analytics service provides out-of-the-box integration with Event Hubs and can be used to process ingested events in real-time. Stream Analytics supports Azure SQL database, Blob storage, Event Hub, Table storage, and Power BI output sink options.


Amazon Kinesis integrates with Amazon CloudWatch service which is a reliable, scalable, and flexible monitoring solution that enables you to collect, view, and analyze CloudWatch metrics for your Amazon Kinesis streams.

Azure Event Hubs don’t provide a built-in monitoring and notification mechanism beyond the basic metrics available on the Azure management portal at the time of writing.

Capacity management

Amazon Kinesis stream throughput is limited by the number of shards within the stream. A resharding operation must be performed in order to increase (split) or decrease (merge) the number of shards. Stream data records are accessible for a maximum of 24 hours from the time they are added to the stream.

Azure Event Hubs ingress is throttled and egress is limited to the amount of capacity provided by the number of throughput units assigned to the stream. Throughput units are provisioned on a best effort basis and may not always be available for immediate purchase. The default Event Hubs message retention period is 24 hours but the Event Hubs Standard tier supports a maximum retention period of 7 days.


Amazon Kinesis uses simple pay as you go pricing and is based on two dimensions: Shard Hour and PUT Payload Unit (25KB payload chunk). The pricing varies by region and is $0.015/hr per shard and $0.014 per 1,000,000 PUT payload units in the US East.

Azure Event Hubs use tiered pricing model and charge by the number of assigned throughput units and ingress events (units of data 64KB or less). The Event Hubs Basic tier costs $0.015/hr per throughput unit and $0.028 per million events while the Event Hubs Standard costs $0.03/hr per throughput unit and $0.028 per million events in the Central US region. Service Bus brokered connections (AMQP connections) are billed separately but the first 100 concurrent connections are free for every Basic Event Hubs namespace, and the first 1,000 concurrent connections per subscription are free for Standard Event Hubs.

Additional resources

Amazon API Gateway and AWS Lambda – Better Together

Modern application development extensively relies on REST APIs. You can hardly find a client application that doesn’t require backend services, and REST protocol is a popular choice because of simplicity and wide platform support. Things start to get complicated when you deploy the REST API to the public domain. Now you have to worry about maintenance, scalability, security, and other responsibilities that come with hosting a publicly accessible web service. Many times these APIs aren’t very complex and don’t require much business logic so the service maintenance overhead can be very significant relative to the overall service functionality. A combination of Amazon API Gateway and AWS Lambda services can significantly reduce the complexities typically associated with hosting and managing your REST APIs.

AWS Lambda service introduction

AWS Lambda is a managed compute service that executes your application code units (referred to as Lambda functions) triggered programmatically or in response to various events raised by other AWS services. Some of the key features of AWS Lambda are:

  • Fully managed – there’s no infrastructure to manage. Simply upload the code and let AWS Lambda take care of the rest.
  • Scalability and high availability – AWS Lambda automatically scales and manages compute resources across multiple Availability Zones.
  • Cost efficiency – only pay for the time your code actually runs, in 100ms increments.
  • Compatibility – currently supports Node.js and Java programming languages.

Amazon API Gateway service introduction

Amazon API Gateway is a fully managed application service that acts as a frontend to your REST APIs and handles traffic management, authorization and access control, monitoring, and API version management. Amazon API Gateway can also generate client SDKs from your REST API for popular development languages and platforms such as JavaScript, iOS and Android. The cost model is very simple and you only pay for the number of your API calls and data transfer out.

Amazon API Gateway and AWS Lambda

As you can see, these services can already be very useful on their own but they also complement each other greatly. Amazon API Gateway tightly integrates with AWS Lambda and allows developers to implement truly serverless REST APIs. Amazon API Gateway endpoints can be configured to invoke AWS Lambda functions which makes it possible to build and deploy publicly accessible, secure, scalable, and reliable REST APIs backed by Node.js or Java code of practically any complexity without having to worry about the infrastructure.

Additional resources

AWS Budgets Feature Overview

Earlier this week, Amazon Web Services announced AWS Budgets – a new feature you can use to track your monthly AWS spending and, optionally, receive SNS notifications when certain spending thresholds are reached. Unlike CloudWatch billing alarms – the only cost monitoring and notification feature previously available, the new AWS Budgets are much more flexible and allow you to slice the costs by service, tag, availability zone, and other dimensions.

I’m sure that many developers will appreciate and take advantage of the new feature to manage costs of their Dev and Test environments. Similarly, many organizations will gain more visibility into their AWS spending across all linked accounts and will be able to proactively address unexpected service usage charges.

You can create a new AWS Budget in the Billing & Cost Management section of the AWS Management Console. Below is a screenshot of a sample budget configuration that would trigger an email alert when the actual usage costs exceed 80% or when the forecasted costs exceed 100% of the monthly budget amount (Figure 1). The “Include costs related to” option lets you narrow down the scope to a specific Availability Zone, Linked Account, API Operation, Purchase Option, Service, or Tag.

Figure 1 - create budget
Figure 1 – create budget

Additional resources

Amazon Web Services Tips for Developers and Solutions Architects

Amazon Web Services (AWS) provides a full range of services that allow developers and solutions architects to design and build scalable and fault tolerant applications without a large up-front hardware investment. There’s a vast amount of information about what AWS has to offer available online but the following features are worth mentioning again.

  • AWS Free Tier: included services and limits, billing alerts
  • AWS Accounts and IAM Users: quick overview and best practices
  • AWS EC2: IAM Roles for EC2, Instance Metadata and User Data
  • AWS S3: Lifecycle rules and Amazon Glacier
  • AWS Architecture Center: reference architectures, architecture whitepapers and official icons

AWS Free Tier

AWS Free Tier allows you to use most of the core AWS services free of charge for 12 months. As of August 2014, these services include, but are not limited to:

  • Amazon EC2 – resizable compute capacity in the Cloud. 750 hours of t2.micro instance usage per month.
  • Amazon S3 – highly scalable, reliable, and low-latency data storage infrastructure. 5 GB of Standard Storage, 20,000 Get Requests and 2,000 Put Requests.
  • AWS Trusted Advisor – AWS Cloud Optimization Expert. 4 best-practice checks on performance and security. Notification and customization features.
  • Amazon Mobile Analytics – fast, secure mobile app usage analytics. 100 Million free events per month.
  • Amazon Cognito – mobile user identity and synchronization. Unlimited user authentication and ID generation. 10 GB of cloud sync storage. 1,000,000 sync operations per month.
  • Amazon DynamoDB – fully managed NoSQL database service with seamless scalability. 100 MB of storage, 5 Units of Write Capacity and 10 Units of Read Capacity.

Additional information about the free AWS offerings can be found on AWS Free Tier page.

Keep in mind that not all of the AWS services are included in the free usage tier so it’s very easy to accidentally start accumulating balance while exploring the various AWS services. Billing alarms can be used to generate notification emails once your account balance reaches a certain threshold to avoid unexpected billing charges.

AWS Accounts and IAM Users

It’s tempting to start using your new AWS account (email address and password combination) to access the AWS resources but that goes against the AWS security best practices. AWS Identity and Access Management (IAM) users and groups should be used to manage access to AWS resources. Here’s a quick summary that describes each of these account types:

  • AWS account – this is the account you create when you sign up for AWS and it represents a business relationship with AWS. AWS accounts have root permissions to all AWS resources and services and should not be used for day-to-day interactions with AWS.
  • IAM users – can be a person, service, or application that needs access to your AWS resources. Best practice is to create IAM users and assign them individual security credentials needed to access AWS services and resources. You can also create an IAM user for yourself, grant it administrative privileges, and use that IAM user to access the AWS management console or the APIs.

For more details, refer to the IAM Best Practices article and the AWS Security Best Practices whitepaper.


It may be challenging to securely distribute and rotate AWS credentials used by your EC2 instances to communicate with other AWS services and resources. In a typical application, the AWS access keys are included in the application configuration file which means that they are visible to anyone who has access to the EC2 instance and makes it difficult to rotate the credentials on a regular basis when you have a large number of running EC2 instances. IAM Roles were designed specifically to address this problem and they let you delegate permissions to your EC2 instances to make API requests without the need to manage security credentials at the application level.

You can read more about AWS IAM Roles in the IAM Roles for Amazon EC2 article.

In addition to AWS credentials, your application may need to retrieve additional information about the EC2 instance it’s running on. For example, when logging application errors you may want to also include the EC2 instance ID or the AMI ID used to launch the instance. Another common requirement is passing configuration information to a newly launched EC2 instance. AWS offers an elegant solution for these problems called Instance Metadata and User Data. The instance metadata is organized in categories and is accessible from within the instance via the following URL:

To get the instance AMI ID, simply call or call to get the hostname of the current EC2 instance.

To retrieve user data available to the instance, use the following URL:

To learn more about, visit the Instance and Metadata and User Data page.


AWS Simple Storage Service (S3) is a well-known cloud file storage service. One of the lesser known features of Amazon S3 is the ability to auto archive content to Amazon Glacier, an extremely low cost cloud archive service optimized for infrequently accessed data. Content archival is controlled by Lifecycle rules that enable you to ensure that data is automatically stored on the cloud storage option that is most cost-effective for your needs. Be aware that Amazon Glacier is not currently available on the AWS Free Tier.

For more information, please visit the Amazon Glacier section of the Amazon S3 FAQs article.

AWS Architecture Center

AWS Architecture Center is the go-to place to find the guidance and best practices necessary to build highly scalable and reliable applications on the AWS platform. Some of the highlights are:

  • AWS Reference Architectures – single-page datasheets that provide you with the architectural guidance on how to take full advantage of AWS services.
  • Architecture Whitepapers from AWS – offers in-depth articles that focus on particular concepts such as fault-tolerance or security best practices in the AWS Cloud. SharePoint 2013 on AWS whitepaper will teach you how to deploy SharePoint 2013 on AWS, following best practices for deploying a secure and highly available architecture across multiple Availability Zones.
  • AWS Simple Icons – an official icon set that includes icons for several AWS products and resources. Available in MS PowerPoint, MS Visio and SVG and EPS formats.