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Serverless appears in various papers and blogs discussing Platform services like Logic Apps and Azure Functions, each having its own particular set of requirements to consider when comparing the two services.
A comparison of Logic Apps versus Azure Functions should always be conducted before deciding which will best meet them.
It should be discussed why serverless computing might be worth exploring, Both Logic Apps and Azure Functions could technically qualify as Serverless services with no infrastructure to manage (done by Microsoft), autoscaling monitoring capabilities or per action or execution charging charges imposed upon them - look at any one of Microsoft's presentation graphics to see that both are integral parts of its Azure Application or Serverless Platform.
An Azure Functions consumption plan offers you both Logic Apps and Azure Functions; however, depending on your requirements, you may choose either or both services for integration scenarios in cloud-native integration scenarios.
In this blog post, we'll briefly review both services before showing how both can work together seamlessly for integration tasks utilizing either or both services as cloud-native solutions in an integration scenario, comparing each and when each should be used for maximum effect.
Azure Logic Apps
What is Azure Logic App? It helps business continuity, business workflows efficiently.
A Logic App acts as a virtual container for one workflow defined by triggers and actions - with triggers initiating processes and activities called actions (for instance, sending HTTP requests), setting daily or hourly cron jobs, etc, to retrieve information from websites, etc.
A Logic App operates on Azure infrastructure (VMs in data centers) but remains hidden from you. Once your workflow is activated and activated via the Logic App Service, some of that infrastructure (indirectly via the Logic App Service) becomes leveraged - you are then billed according to what actions and triggers are executed, with scaling automatically taking care of itself, such as increasing requests and instances until certain limits have been reached (See Limitations of Logic App).
Azure Functions
Azure Functions, part of the Azure Web + Mobile App Services suite, allows business processes to develop meaningful, reusable methods that can be easily shared between services.
They can be written in different programming languages like Node.js, C#, F#, Python, PHP, Java, and scripting languages Bash PowerShell CMD- BAT files, etc, typically designed to perform one specific purpose or respond to events across other services.
Azure Functions rely heavily on WebJobs SDK runtime as its cornerstone; this framework simplifies developing background processing code that runs in Microsoft Azure.
Furthermore, Functions use declarative binding and trigger mechanisms that interact with various Azure services like Storage, Cosmos DB, and Service Bus.
How Do Azure Functions And Logic Apps Differ?
At first, we covered both Logic Apps and Azure Functions separately; now let's difference between azure logic apps and azure functions, how they function together and when to choose between one or the other for use in business environments.
Herein, we will also address differences such as developer experience vs deployment options - something the following paragraphs will address further.
Developer Experience
As both Visual Studio and your browser provide monitoring tools for developing Azure Functions and Logic Apps, their respective experiences differ slightly; when creating functions, they tend to perform better, while when designing a workflow for Logic Apps, the responsiveness is slower due to browser restrictions on responsive workflow designers.
Also, with functions, you generate code, while when designing workflow with Logic Apps, it works more like no-code or low-code development.
Unlike programming, Azure Functions provide greater power with fewer restrictions when dealing with complex circumstances or requirements, which imposes flexibility and responsibility on you.
Triggers (managed connectors) and actions are predefined within logic apps, while variables, built-in expressions, or calls to an API or Function may also be utilized. Furthermore, custom connectors may also be created if needed, although binding will likely make this more challenging.
Connectivity
Connectors are at the core of Logic Apps, providing connectivity with processes. Connectors allow for flexible manipulation of stateful workflow and payload flow insertion/exclusion within your process flow.
Microsoft offers numerous connectors ranging from Azure Services to popular SaaS applications and ongoing investments into developing more connectors if one doesn't already exist - creating custom connector templates in Azure Marketplace can assist with that, too.
As part of creating a process, each connector includes an API connection (connectors are wrappers around an API and actions) and securely stored credentials that you will use when creating and selecting connectors for authentication purposes.
After successfully authenticating, once the chosen connector has its own managed API connection that will appear under your resource group where your Logic App resides - these connections may even be reused across a wide variety of other Logic Apps.
Azure Functions such as Storage, Event Hubs, Service Bus and Cosmos DB do not utilize connectors like their counterpart Logic Apps.
Instead, they depend on declarative triggers and bindings for data access by specifying connection strings and parameters based on which binding you select. Furthermore, additional binding extensions may be added via WebJob SDK extensions to extend binding options even further compared to what Logic Apps offers.
Security
At this point, we discussed authentication for logic app and azure function security bindings and connection strings in Azure Function bindings.
Each connection varies in its security depending on its API; for instance, it requires signing into Dynamics with an active Dynamics account to sign into it; when using HTTP triggers with processes using Shared Access Signature URLs instead, clients must add a Shared Access Signature created using an easily regeneratable secret key to access an HTTP endpoint within your Logic App; additionally, you could add Azure API Management before that to safeguard this endpoint - see Protecting Azure Logic Apps With API Management.
Security options vary when using Azure Functions: Authorization keys can secure publicly exposed functions (HTTP and WebHook Binding) generated when creating processes and regularly renewed.
Furthermore, authentication features from Azure AD, Google Apps for Work or Facebook authentication can also be configured through general settings - plus lightweight Azure Function proxies or API Management can help control HTTP/WebHook-triggered functions.
Exception Handling
Exception handling is a critical element of Logic Apps and Azure Functions, helping make them more robust by handling errors when they arise.
Although some mechanisms for handling exceptions already exist in both applications (Logic Apps provides built-in retries, scopes and run-after options; Azure Functions follows traditional try/catch patterns), designing this into your solution requires deliberate design work; it doesn't just happen on its own - unlike with Azure Queue/Blob Storage functionality where out-of-the-box retries exist, additional information on error handling with Azure Functions can be found by visiting Azure Functions error handling page.
State
Azure Functions have always been stateless, accepting data as input, processing it, and initiating one or more actions as output - acting like one big software switch.
Microsoft recently implemented durable functions, also referred to as orchestrator functions, into its operating systems to change this situation. Microsoft leverages Durable Task Framework to deliver long-running features to Azure Functions through Durable Functions, offering stateful actors as long-running tasks with predefined timeouts without external storage requirements - these long-running processes are built into Logic Apps as part of disaster protection.
Scaling
Consumption models for Logic Apps and Azure Functions feature auto-scale capability; when your load increases, these services may adjust automatically up to an agreed-upon point, with specific connections such as File System being limited to 100 calls per minute for scaling purposes.
Azure Functions, like Logic Apps, can be consumed; instances of Azure Functions hosts are dynamically added and removed based on how many events come through - this auto-scaling plan enables auto-scaling.
They may also run under an App Service Plan where dedicated VMs with basic, standard premium or isolated SKUs are assigned per plan - this may be more suitable if your processing power needs exceed those defined within a consumption plan or you need your function apps running continually.
Deployment
Use Azure Resource Manager (ARM) templates when deploying resources in Azure app service, such as Logic Apps and Azure Functions.
Both portal automation scripts or Visual Studio support these templates; automating deployment may be possible using these.
With Azure Functions, continuous deployments are easily set up through triggers from Bitbucket, Dropbox, Git, GitHub, OneDrive or VSTS (see Leveraging Functions on the Azure storage Platform blog post for an example of such stimuli).
Furthermore, preview deployment slots allow testing out future releases before swapping out their deployment slot for runtime version production deployment.
Monitoring
Monitoring Azure Functions and Logic Apps can be accomplished using OMS, Application Insights, Log Analytics capabilities, and built-in features.
Logic Apps has an in-depth run history feature that lets you analyze specific runs thoroughly based on date or status filters; additionally, it connects directly with Azure Operation Management Suite (OMS), making interaction simple - for instance, enabling interaction through just one button click gives access to OMS for searching recorded attributes and running histories.
Your Azure Functions provide access to a monitor tab where you can review their execution history, with live event streams that display processing statistics in near real-time graphs and full integration workflow with Application Insights for deeper analytics.
Working With Logic Apps And Functions
An example Logic App function would convert Euros to Dollars or vice versa, for example, when selling items online using local currency.
When your Logic App consumes this order request from a public-facing website selling items using local currency, once finished, it should create a consistent message containing money converted from EUR to USD using expressions (there currently being none available); so to accomplish this conversion you'd call upon another function that takes care of that task for you.
Conclusion
In this blog article, we addressed azure logic apps and azure functions together on cloud-native integration scenarios, the differences between them, when to utilize each, their usefulness to you, and when you might benefit most from their usage.
Logic Apps and Azure Functions offer true PaaS (Platform as a Service), solutions that enhance cloud service solutions.
