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Rutika Khaire
Rutika Khaire

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How to Scale Your Application to Handle Peak Loads and Increase Throughput

Introduction: The Party Planner’s Dilemma

Imagine you're hosting a party. You plan for 50 guests, but suddenly 200 people show up. You need more food, more chairs, and a way to keep everyone happy without chaos. This is exactly what systems face during peak loads. How to keep everything running smoothly?


1. Scaling Up: Adding Chairs to the Party

Scaling your system during peak loads is like finding extra chairs when more guests arrive. Scaling ensures that the application has enough resources to handle increased demand.

Add chairs

Here’s how to do it with Azure:
Vertical Scaling (Adding More Power):
Adding resources to existing servers, like upgrading a chair to a sofa.
Example: If your Azure App Service instance needs more resources, scale up to a higher pricing tier.

How to Do It?

  • Navigate to your App Service.
  • Select Scale Up (App Service Plan) and choose a higher tier (e.g., Standard to Premium).

Horizontal Scaling (Adding More Machines):
Adding more servers, like borrowing chairs from your neighbors.
Example: During a flash sale, e-commerce platforms add more servers to handle the load.

How to Do It?

  • Go to your App Service.
  • Select Scale Out (App Service Plan) and configure autoscaling rules based on metrics like CPU usage or request count.

Azure-Specific Tip: Use Azure Monitor Autoscale to define rules like “Add one instance if CPU usage exceeds 70% for 5 minutes.” Refer this for more detailed information.


2. Thresholds: Knowing Your Party’s Limit

Thresholds
Every system has a breaking point—its threshold. It’s like knowing your living room can only hold 30 people before things get cramped. Thresholds are the breaking points of a system. Knowing them helps avoid disasters.

Identify Thresholds in Azure:
Example: Your SQL Database might have a DTU (Database Transaction Unit) limit of 1000.

How to Do It in Azure:

  • Use Azure Monitor to track resource metrics like DTU usage, CPU percentage, and memory utilization.
  • Set up Alerts in Azure Monitor for critical thresholds. For instance, send an email when database utilization exceeds 85%.

Set Alarms:
Example: Monitor your Azure Function’s execution time or failures.

How to Do It in Azure:

  • Navigate to Azure Monitor → Alerts → New Alert Rule.
  • Configure conditions like “Trigger an alert if CPU utilization > 80% for 5 minutes.”

3. Handling Thresholds: Avoiding the Crash

Avoiding the Crash
What happens when you hit a threshold? Use these strategies with Azure:

Graceful Degradation:
Example: Serve cached product pages if your backend API is overloaded.

How to Do It in Azure:

  • Use Azure Front Door to cache and serve static content from edge locations.
  • Configure Azure CDN to offload traffic from your backend during peak times.

Queueing Systems:
Example: Process orders in batches during peak traffic.

How to Do It in Azure:

  • Use Azure Service Bus or Azure Queue Storage to enqueue requests for asynchronous processing.
  • Implement a Logic App or Azure Function to process messages from the queue.

4. Throughput: Keeping the Line Moving

Throughput
Throughput is the speed at which you can serve your guests. In tech terms, it’s how many requests or tasks your system can handle per second.
Here’s how to improve it with Azure:

Optimize Database Performance:
Example: If your Azure SQL Database is slow, optimize queries and scale up.

How to Do It in Azure:

  • Use the Query Performance Insight feature in Azure SQL to identify slow queries.
  • Scale your database using the DTU-based or vCore-based model.

Use Load Balancers:
Example: Distribute traffic evenly across multiple virtual machines.

How to Do It in Azure:

  • Set up Azure Load Balancer for Layer 4 (TCP/UDP) traffic.
  • Use Application Gateway for Layer 7 (HTTP/HTTPS) traffic, and enable autoscaling.

Implement Caching:
Example: Reduce repeated database calls for product details.

How to Do It in Azure:

  • Use Azure Cache for Redis to store frequently accessed data like product details or user sessions.

Compress Responses:
Example: Compress API responses to reduce latency.

How to Do It in Azure:

  • In Azure App Service, enable compression under Configuration → General Settings.

5. Put It All Together: The Ultimate Party Plan

Example Scenario:
You’re running a ticket-booking platform for a concert, and traffic surges at ticket release.

Scaling:

  • Use Azure App Service autoscaling to handle increased HTTP requests.
  • Scale your Azure SQL Database to a higher tier (e.g., Standard to Premium).

Thresholds:

  • Monitor DTU utilization for Azure SQL Database using Azure Monitor.
  • Set alerts for API response times exceeding 500ms.

Throughput:

  • Cache event details using Azure Cache for Redis.
  • Use Azure Front Door to route traffic globally and serve cached content faster.
  • Implement message queues with Azure Service Bus to process ticket purchases asynchronously.

Conclusion: Keep the Party Going!

Azure provides an array of tools to manage peak loads, thresholds, and throughput efficiently. With features like autoscaling, Azure Monitor, Service Bus, and Front Door, you can ensure your system remains reliable and performant—even under heavy demand.

By implementing these best practices, your applications will stay resilient, agile, and ready to handle any traffic surge.

This blog is designed for novices to scaling or those with intermediate skills who want to strengthen their understanding of handling peak loads, thresholds, and throughput. Using relatable analogies and real-world scenarios, I have tried to break down these concepts into easy-to-grasp sections.

Reference Links
Autoscaling

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