Benefits and Challenges of Multi-Cloud Integration

Before we get into the details, let's answer the following questions:

What is Cloud Integration Architecture? A cloud integration architecture is a combination of cloud components and multiple cloud providers that enable data exchange across multiple data centers.

For example, let's say you have a large banking solution. Some banks don't want to migrate centrally secure data. I want to store it in an on-premises data center. But they cannot avoid clouds. Migrate existing projects, newly started projects, or even entire call centers and back offices to the cloud. Building this complex architecture requires knowledge of the integration services and tools provided by the cloud.

Let's take a look at the components offered by AWS, Google Cloud, and Azure.

Common Integration Service

It's important to understand common cloud integration best practices and patterns. But it's also important to know exactly what each cloud provider offers. This section describes the main integrated services offered by AWS, Google Cloud, and Azure. We will also discuss the pros and cons of each service.

AWS

AWS has several integrated services that offer power and simplicity.

SQS (Simple Queue Service)

SQS is a simple query service or distributed queuing system. A queue that stores messages for later processing. SQS is a pull-based service that enables the decoupling of cloud components and microservices.

Advantage:

• Including dead letter queue:

1. Automatically detach unprocessed messages and move them to the dead-letter queue
2. Choosing Between Standard Queues and FIFOs

• Automatic deduplication:

1. SQS automatically detects and removes duplicate messages.

Cons:

• Does not support one-to-many message broadcasting

SWF (Simple Workflow Service)

SWF is a task coordination and workflow service. This allows you to set up parallel and sequential workflows. You can build reliable distributed systems where tasks are logical units or functions of your application. SWF is suitable for processing human-based operations like order workflow or procedural requests.

Pros:

• Reliability:

1. Workflows and state tracking are reliable as they run at high-availability data centers

• Flexibility and logical separation:

1. SWF allows architects and users to modify workflow elements easily. Also, SWF separates the control flow of your background job

Cons:

• A lot of bugs in the AWS Management Console and a lack of general support
• The setup process is difficult and takes a lot of time
• Lack of limit control tracking:

1. It can lead to throttling issues

AWS Step Functions

AWS step functions allow us to create a serverless workflow or state machines; for example, to automate call center tasks. Step Functions is an orchestration function that orchestrates other Lambda functions.

Pros:

• Decreasing application complexity by decoupling workflow logic from business logic

Cons:

• Step Functions uses a specific state machine to define workflows, helpful only for the Step Functions service. This can lead to vendor lock-in. 

Google Cloud (GC)

GC has an integration ecosystem, Integration-Platform-as-a-Service (iPaaS). It offers various tools and services to manage and connect your applications. Google Cloud iPaaS includes the following services:

Integrated Designer

Integration Designer is his code-free UI tool that offers the possibility to create workflows consisting of triggers and tasks (see below). Tasks and triggers are connected by edges, forks, and joins. This service is very similar to SWF. trigger

Triggers are important workflow elements. A trigger is typically the entry point of a workflow, representing an event that initiates a task. For example, API triggers or Pub/Sub triggers.

task

A task is a unit of work (or function) that comes after a trigger. An example is data mapping, which allows you to integrate one data model into another. Some predefined tasks include Call Integration Task, For Each Parallel Task, For Each Loop Task, Timer Task, etc.

Drawbacks:

• Lack of data centers compared to Azure and AWS
• It's a relatively new framework. Some features are in preview (or beta) and may contain some bugs.

Azure

Azure offers a set of Azure integration services. Contains various services for setting up powerful integrations between applications. Below are some of the most powerful integration services Azure offers.

API Management

API Management is an API gateway service that integrates multiple APIs and connects Azure Functions, Logic Apps, and Service Bus.

Advantage:

• API Management provides authentication, authorization, cached responses, granular quotas and limits, and much more.
• Flexible customization with API guidelines

Cons:

• The developer portal contains many usability issues and bugs.
• Scaling costs may be too high. API management scales automatically. However, there is not enough transparency about the cost of scaling.

Logic App

Logic Apps are low-code, serverless workflow integration tools such as GC Integration Designer and AWS SWF.

Advantage:

• This service can connect to SQL Server, Event Grid, Oracle, ServiceNow, and Office 365. Choose from over 200 connectors.
• Ability to host maps and schemas locally

Cons:

• Complex integration workflows are difficult to manage and maintain
• User interface issues, especially in complex workflows

Bus

A Service Bus is a service that implements the event bus pattern. It provides an event bus based on the integrated principles of queuing and publish/subscribe when one component produces a message, and another consumes it.

Advantage:

• The service also supports translations, dead letters, topic-based multi-consumer logic, and other features.
• Powerful message forwarding and filtering capabilities

Cons:

• Slow HTTPS connection performance
• Options to monitor messages, queues, and topics are fairly limited
• No built-in UI tools to debug messages, queries, and filters

Event Grid

Event Grid brings together cloud resources that generate events (publishers) and resources that process events (subscribers). Event Grid is similar to AWS SNS. It's also based on a push approach. Event Grid monitors events for components and can trigger other events when assigning messages. For example, an application can send messages to Azure queues and send email notifications.

Advantage:

• Enterprise Integration:

1. Supports almost any Azure event source. B. Functions, Event/IoT Hubs, Logic Apps, Service Buses, SignalR, etc.
2. Contains options for monitoring and debugging messages
3. Includes automatic dead-letter queue

• Low Cost:

1. Our per-event pricing model keeps costs very low.

Cons:

• You can improve the transparency of how undeliverable messages are stored and activated.

Azure Arch

Azure Arc is a service that enables you to connect services from different cloud providers and implement multi-cloud integration. This service is used as the primary integration service for banking multi-cloud applications. 

Advantage:

• Supports services such as SQL Server and Kubernetes
• Supports Windows and Linux operating systems

Cons:

• Agent connections can be unstable and difficult to debug.

Conclusion

In this article, we've covered the key components for building cloud integration. However, the integration solution does not have to be enterprise-grade.

They can interfere or become smaller. For example, let's say you have application A that needs to exchange data with application B. You can create integration middleware using Azure Durable Functions or AWS Step Functions. These services allow you to create workflows for data mapping, notifications, and even simple analytics.