API Gateway Scalability: Best Practices

published on 10 October 2024

Want to scale your API gateway without headaches? Here's what you need to know:

  • Design smart: Use layered architecture and microservices
  • Plan resources: Analyze traffic and set up autoscaling
  • Boost speed: Cache data and optimize database connections
  • Monitor closely: Track key metrics like requests per second
  • Secure while growing: Use strong auth and rate limiting

Key scaling strategies:

  1. Implement load balancing
  2. Use cloud services (e.g., AWS API Gateway)
  3. Adopt serverless architecture
  4. Optimize data structures and caching
  5. Use blue-green and canary deployments
Aspect Best Practice
Performance Cache common data, use efficient data structures
Security Implement OAuth or API keys, guard against DDoS
Monitoring Set up detailed logs and alerts
Deployment Use automated, gradual rollout strategies
Cost Choose the right API type, use free tiers, optimize calls

Remember: Start testing early, monitor constantly, and be ready to adapt. With these practices, you can build an API gateway that grows with your business while staying secure and cost-effective.

Common API Gateway Scaling Issues

API gateways can hit a wall when demand skyrockets. Let's dive into the typical roadblocks and what to keep an eye on.

Performance Bottlenecks

What slows down your API gateway? Here are the usual suspects:

  • Sluggish networks
  • Overworked servers
  • Clunky database queries
  • Slow third-party services
  • Too many cooks in the data kitchen

Timeout Troubles

When your gateway's left hanging, timeouts happen. Here's a quick rundown:

Timeout Type What's Going On
Connection Can't reach the backend
Request Client's taking too long
Response Backend's dragging its feet
Socket Communication hiccup
Global Catch-all time limit
Circuit Breaker Temporary traffic stop

Scaling Headaches

As you grow, you'll face:

  • Uneven traffic distribution
  • Lost services in the crowd
  • Performance tracking nightmares
  • Keeping data in sync across instances

Real-World Scaling Snags

Here's what happens when theory meets reality:

1. Transaction Overload

An API choked at 40 transactions per second when it needed 100. Talk about a last-minute scramble!

2. WebSocket Woes

DAZN hit a wall with AWS API Gateway's 1.8 million new WebSocket connections per hour. Not enough for live sports!

3. Payload Bloat

Massive order histories turned quick API calls into slow-motion replays.

4. Database Bottleneck

A customer database maxed out at 200 transactions per second. Scaling up meant downtime.

Metrics That Matter

Keep these on your dashboard:

  • Requests per second
  • Response times
  • Error rates
  • Resource use (CPU, memory, network)
  • Concurrent connections

Stay on top of these, and you'll spot trouble before it snowballs.

Top Ways to Scale API Gateways

Scaling API gateways is crucial for handling increased traffic. Here's how to boost your gateway's performance:

Design Choices

Think big with your design:

  • Split your gateway into layers
  • Break down your monolith into microservices
  • Use load balancing to spread traffic evenly

Gloo Edge users often start small and grow fast. They use Gloo Federation to manage multiple Edge instances from one place as they expand.

Resource Planning

Plan your resources smart:

  • Analyze current and expected traffic
  • For Gloo Edge, you usually need two Envoy proxy instances
  • Set up autoscaling rules

Improving Speed

Boost speed with these tricks:

  • Cache common data
  • Reuse database connections
  • Handle tasks in the background

One company added pagination for large payloads. This cut down response sizes and sped up their API.

Tracking and Visibility

Keep tabs on your system:

  • Watch key metrics like requests per second and error rates
  • Set up detailed logs
  • Use monitoring tools that alert you early

Security While Scaling

Don't let growth weaken security:

  • Use strong auth like OAuth or API keys
  • Control request rates
  • Guard against DDoS attacks

Managing Data

Scaling API gateways? Data management is key. Let's dive into shared states, data structures, and database sharding.

Shared States and Data Consistency

Keeping data consistent across multiple instances is a must. Here's how:

  • Sync up: Use mechanisms to keep all instances on the same page
  • Cache it: Implement caching to take the load off your backend

Database Sharding

Sharding splits data across servers. It's a game-changer for scaling databases. Why? It boosts performance, throughput, and availability.

Here's how to nail sharding:

1. Pick the right shard key

Your shard key decides how data spreads out. For example:

Shard Key Distribution
User IDs 1-2000 in Shard 1, 2001-4000 in Shard 2
Order IDs 1-2000 in Shard 1, 2001-4000 in Shard 2

2. Keep an eye on your shards

Regular monitoring and rebalancing keep things running smoothly.

3. Use sharding-friendly databases

MongoDB and Cassandra do the heavy lifting for you.

Optimizing Data Structures

Speed up routing and lookups with better data structures:

  • Hash tables: Quick key-value lookups
  • Trees: Efficient range queries

Caching Strategies

Cache smart to reduce backend load:

  • In-memory caches: Lightning-fast access
  • Distributed caches: Share data across instances

Asynchronous Processing

Process tasks asynchronously to handle more requests. This move can scale your system and make it more resilient.

Rolling Out Updates

Updating your API gateway is crucial. Let's look at some ways to do it right.

Canary Deployments

Canary deployments let you test new API versions safely. Here's how:

1. Add canary settings to your deployment stage.

2. Set canarySettings:

  • Deployment ID
  • Canary traffic percentage
  • Canary stage variables

3. Monitor using separate log groups:

  • Production: API-Gateway-Execution-Logs/{rest-api-id}/{stage-name}
  • Canary: API-Gateway-Execution-Logs/{rest-api-id}/{stage-name}/Canary

4. If the canary performs well, promote it to production.

Blue-Green Deployments

Blue-green deployments use two environments:

Environment Purpose
Blue Current production
Green New version testing

To do a blue-green deployment:

  1. Set up green environment with new version
  2. Test green environment
  3. Switch traffic from blue to green
  4. Keep blue as a rollback option

A startup used blue-green deployments after failed releases. They now release multiple times daily, improving team coordination.

Automated Deployment

Automate your deployment to save time:

  1. Identify needed AWS CLI commands
  2. Add commands to your CI pipeline
  3. Consider AWS CodeStar for a full CI/CD pipeline

Updating API Gateway and Deployments

Use these AWS CLI commands to update:

# Update API Gateway
oci api-gateway gateway update --gateway-id ocid1.apigateway.oc1..aaaaaaaab______hga --display-name "Hello World Gateway - version 2" --wait-for-state ACTIVE

# Update API Deployment
oci api-gateway deployment update --deployment-id ocid1.apideployment.oc1..aaaaaaaaab______pwa --specification file:///Users/jdoe/work/replacement-specification.json

Check the status:

oci api-gateway work-request get --work-request-id <work-request-ocid>
sbb-itb-9890dba

Checking Scalability

To make sure your API gateway can handle more traffic, you need to test it thoroughly. Here's how:

Load Testing

Load testing shows how your API gateway performs under normal traffic. Here's what to do:

  1. Set clear goals for requests per second
  2. Pick a tool like JMeter or Postman
  3. Mimic real user behavior
  4. Watch key metrics:
Metric What It Means
Status codes Are responses successful?
Latency How much time does the gateway add?
Throughput How many requests per second?
CPU load Is it stable under high traffic?
  1. Start small and ramp up

Stress Testing

Stress testing pushes your API gateway to its limits:

  1. Use the same tools, but crank up the settings
  2. Watch for errors or weird behavior
  3. Find out where it breaks

Real-World Example: JustEat's Smart Gateway

JustEat handles about 300 million requests daily. They tested their gateway like this:

"We used Hey for stress testing with 300 concurrent connections, and Locust to create test scripts on the fly. We started with a fake API, then ramped up to 50 million requests, checking things like status codes and CPU load."

Best Practices

  1. Start simple, test often
  2. Use virtual users to simulate traffic
  3. Check for specific conditions during tests
  4. Set pass-fail criteria
  5. For WebSocket APIs, watch connection limits
  6. Test across regions if needed

Scaling in the Cloud

Cloud services make scaling API gateways a breeze. Here's how:

AWS API Gateway: Auto-scaling Beast

AWS API Gateway

AWS API Gateway handles scaling for you. It can take:

  • 10,000 requests per second
  • PLUS an extra 5,000 requests per second burst

You focus on your API. AWS handles the rest.

Go Multi-region

Want better availability and less lag? Spread your API across regions:

1. Regional APIs: Put your API in multiple AWS spots.

2. Failover: Use Amazon Route 53 to switch between regions if one fails.

3. Global Tables: DynamoDB Global Tables copy data across regions easily.

Serverless: Scale Without Thinking

Serverless setups (like AWS Lambda) grow with your traffic. You get:

  • Pay for what you use
  • No server headaches
  • Automatic growth

Cloud Tools You'll Love

Tool What It Does Cool Feature
AWS WAF Keeps APIs safe Stops web attacks
CloudWatch Watches your API Spots issues fast
RDS Proxy Helps databases Prevents overload

JustEat: Real-world Scaling

JustEat handles 300 million requests daily. How? Smart testing:

"We used Hey for stress tests with 300 connections, and Locust for on-the-fly scripts. We started small, then ramped up to 50 million requests, checking status codes and CPU load."

This approach helped JustEat's gateway handle massive scale.

Do These Things

  1. Cache your API
  2. Use SSL certs for backend auth
  3. Test your failover often
  4. Stay updated on new features

Keeping Costs Down While Scaling

Want to scale your API gateway without breaking the bank? Here's how:

Pick the Right API Type

AWS offers two main API types:

API Type Cost Features
HTTP API Cheaper Basic
REST API Pricier Advanced

Go for HTTP APIs if you don't need fancy features. They're up to 70% cheaper than REST APIs.

Use the Free Tier

AWS gives new users a sweet deal:

  • 1 million API calls (REST and HTTP)
  • 1 million messages + 750,000 connection minutes (WebSocket)

This lasts a year. Use it wisely.

Set Up Usage Plans

Control API access to avoid surprises:

  • Set throttling limits
  • Create quotas
  • Track usage per API key

Cache Smart

Caching cuts backend calls. But be smart:

1. Cache only what's needed

2. Set proper TTLs

3. Use regional caching for speed

Optimize Your Calls

Every call costs. Cut the fat:

  • Combine calls when possible
  • Use batch processing
  • Implement pagination

Consider Alternatives

As you grow, other options might be cheaper:

"An Application Load Balancer (ALB) might save you money at scale, unless you need specific API Gateway features."

Monitor and Adjust

Keep an eye on things:

  • Use AWS CloudWatch
  • Set up spike alerts
  • Review and tweak regularly

Use CDNs

CDNs like Amazon CloudFront can slash data transfer costs, especially for static content.

Step-by-Step Guide to Scale

Want to scale your API gateway? Here's how:

1. Assess Current Performance

First, measure your API gateway's performance:

  • Track requests per second
  • Monitor response times
  • Check error rates

Use AWS CloudWatch for these metrics.

2. Implement Load Balancing

Distribute traffic across multiple API gateway instances:

Load Balancer Use For
ALB HTTP/HTTPS
NLB TCP/UDP

3. Enable Caching

Reduce backend calls with API caching:

aws apigateway update-stage \
    --rest-api-id <api-id> \
    --stage-name <stage> \
    --patch-operations op=replace,path=/cacheClusterEnabled,value=true

4. Set Up Auto-Scaling

Configure auto-scaling:

  • Set min/max instance counts
  • Define CPU threshold (e.g., 70%)

5. Optimize Backend Services

Prep your backend for increased load:

  • Scale databases
  • Use async processing for time-consuming tasks

6. Use Regional APIs

Switch to regional APIs:

aws apigateway create-rest-api \
    --name "MyRegionalAPI" \
    --endpoint-configuration '{ "types": ["REGIONAL"] }'

7. Implement Throttling

Protect your API from traffic spikes:

aws apigateway update-stage \
    --rest-api-id <api-id> \
    --stage-name <stage> \
    --patch-operations op=replace,path=/throttling/rateLimit,value=1000

8. Monitor and Adjust

Keep tabs on your API:

  • Set CloudWatch alarms
  • Review logs
  • Tweak scaling as needed

Wrap-up

Scaling API gateways is crucial for system performance as traffic grows. Here's what you need to remember:

  • Plan a tiered gateway setup to divide tasks between app and platform teams
  • Focus on scaling the data plane and auth services, not the control plane
  • Use automation for gateway provisioning and setup
  • Monitor performance and resource use closely

Reddit scaled to 1 billion monthly page views using a mix of HAProxy and Nginx for load balancing.

Future trends to watch:

Trend Impact
Serverless Computing More elastic scaling
AI-Powered Features Smarter traffic routing
Enhanced Security Improved auth and encryption

Scaling API gateways isn't just about handling more requests. It's about building a system that grows with your business while staying secure and cost-effective. Keep testing, monitoring, and be ready to adapt to new tools and methods.

FAQs

How to make an API gateway scalable?

To scale your API gateway:

1. Test under load

Push your gateway to its limits. Find out how many requests it can handle before it starts to slow down.

2. Keep an eye on performance

Watch response times as you grow. They should get better when you spread the load across more servers.

3. Scale up, then out

Start by beefing up your hardware. It's cheaper at first. As you grow, add more servers.

4. Don't wait

Address scaling early. One company found their API could only handle 40 transactions per second instead of the needed 100 - just two weeks before launch!

How do you scale your API?

There are two main ways to scale:

Method What it means When to use it
Vertical Upgrade your hardware When you're just starting out
Horizontal Add more servers When you're growing fast

To scale effectively:

1. Think ahead

Build with scaling in mind from day one.

2. Use the cloud

Services like AWS API Gateway can handle tons of requests. We're talking 10,000 per second, with room for 5,000 more in bursts.

3. Know your limits

AWS API Gateway, for example, allows 500 new WebSocket connections per second by default. That's up to 1.8 million in an hour.

4. Consider your needs

DAZN found even 1.8 million new WebSocket connections per hour wasn't enough for streaming live sports updates.

Related posts

Read more