Global users for twtech application.

 

If twtech application has global users, there will be several architectural, performance, and cost considerations — especially when using Amazon CloudFront, S3, and global infrastructure services.

Here’s a breakdown of key factors and best practices for serving a global user base effectively:

 Key Challenges of a Global Audience

Challenge	Impact	Solution
High Latency	Slower page/app load times	Use CloudFront with PriceClass_All, origin caching, and geo-edge routing
Data Compliance (GDPR, etc.)	Legal/regulatory risk	Store/replicate data regionally, use encryption & policies
Content Synchronization	Stale or inconsistent content	Use S3 CRR, CloudFront cache invalidation, or versioning
Availability & Failover	Risk of downtime in a region	Use Route 53 health checks, multi-region deployments
Costs (Bandwidth)	High egress costs in expensive regions	Use caching (CloudFront), choose price class carefully

 Architecture Strategy for Global Users

1. CloudFront CDN

• Deploy with Price Class All for best latency globally
• Use geo restriction only if required
• Enable origin failover for HA
• Customize caching policies per content type

2. S3 with Cross-Region Replication (CRR)

• Set up CRR if users upload content globally
• Use regional S3 buckets close to end users for write-heavy use cases
• Integrate with CloudFront to reduce read latency

3. Application Layer (EC2 / ECS / Lambda / API Gateway)

• Use regional deployments for dynamic content (API endpoints)
• Consider Global Accelerator or Route 53 latency-based routing to direct users to the nearest region

4. Authentication and Identity

• Use Amazon Cognito or Auth0 with multi-region support
• Minimize round-trips to a single auth server (add caching, short tokens)

 Optional Enhancements

Feature	Description
AWS Global Accelerator	Optimizes TCP/UDP routing globally (better than DNS)
Route 53 Geo/Latency Routing	Routes users to the closest healthy endpoint
Regional Lambda@Edge / Edge Functions	Run logic (auth, redirects, headers) near the user
Multi-AZ/Multi-Region DB	Global databases (Aurora Global, DynamoDB Global)
Edge Caching + Regional Origin	Cache dynamic or static content for each continent

 Analytics & Monitoring

Track these to assess and optimize performance:

• CloudFront Logs: Viewer country, cache hit ratio
• Real User Monitoring (RUM): Performance from end-user location
• AWS CloudWatch / X-Ray: Latency per region
• Route 53 Health Checks: Endpoint health worldwide

 Next Steps

To tailor this better:

• Does twtech use S3 + CloudFront for static assets only, or are there APIs too?
• Is twtech-app deployed in multiple AWS regions, or centralized?
• Does twtech needs compliance with data residency laws?

CloudFront | Cache Invalidations.

 

CloudFront Cache Invalidation allows twtech to remove cached content from edge locations before it naturally expires (based on TTLs), ensuring users receive updated or corrected versions of twteh content immediately.

 Benefits of Cache Invalidation:

CloudFront caches content at edge locations for performance and cost savings. But when the origin content changes, that cached version can become stale unless:

·        twtech versions its files (recommended), or

·        twtech explicitly invalidate the old content

 Common Use Cases

·        After deploying new versions of assets (JS, CSS, images)

·        Removing incorrect or sensitive content quickly

·        Updating frequently changing static files

 How CloudFront Cache Invalidations Works

Invalidation removes specific files from the cache. The next time someone requests those files, CloudFront fetches the latest version from the origin.

·        twtech  needs to specify the paths (wildcards supported)

·        CloudFront returns HTTP 200 OK after successful invalidation

 How twtech Creates Invalidation

AWS Console

1.     Go to your CloudFront Distribution

2.     Choose the “Invalidations” tab

3.     Click “Create Invalidation”

4.     Enter file paths (e.g.):

# bash 

/index.html

/images/logo.png

/assets/*

5.     Submit

AWS CLI

#  bash 

aws cloudfront create-invalidation \

  --distribution-id YOUR_DISTRIBUTION_ID \

  --paths "/index.html" "/assets/*"

 Syntax Tips

Path	Description
/index.html	Only invalidates /index.html
/assets/*	Invalidates everything under /assets/
/*	Invalidates entire distribution (expensive)

 Cost of Invalidation

·        First 1,000 paths/month: Free

·        Additional paths: $0.005 per path (as of June 2024)

·        One /* wildcard counts as one path

 What Invalidation Doesn’t Do

·        Doesn’t delete content from your origin

·        Doesn’t purge CloudFront logs or configurations

·        Doesn’t remove objects from S3

twtech Best Practices

·        Prefer versioning twtech files (e.g. main.v2.js) to avoid invalidations

·        Use invalidations for critical fixes or edge cases

·        Group invalidations together (use wildcards when practical)

·        Monitor costs if twtech invalidates frequently.

CloudFront Geo Restriction.

 

CloudFront Geo Restriction (also called Geo Blocking) allows twtech to allow or block content delivery to users based on their geographic location.

This feature helps comply with content licensing agreements or limit access from specific regions.

How  CloudFront Geo Restriction Works

When a viewer requests content via CloudFront, the service detects the viewer’s country using the IP address. Based on the geo restriction rules twtech has configured, CloudFront either:

·        Allows access, or

·        Blocks access and returns an HTTP 403 Forbidden error

 Use Cases

·        License restrictions: Block streaming content in countries where it’s not licensed.

·        Compliance: Prevent access from sanctioned countries.

·        Security: Restrict regions with high abuse traffic.

·        Marketing: Target content only to specific countries.

 Configuration Options

CloudFront supports two modes of geo restriction:

Mode	Description
Allow list	Only specified countries can access your content. Others receive 403 errors.
Block list	All countries except those specified can access your content.

How to Set It Up

Via AWS Console:

1.     Go to CloudFront in the AWS Console.

2.     Select your distribution.

3.     Go to the “Restrictions” tab.

4.     Under Geo restriction, choose:

o   Blacklist (block countries)

o   Whitelist (allow only specific countries)

5.     Select countries from the list.

6.     Save changes.

Via AWS CLI:

#  bash

 aws cloudfront update-distribution \

  --id YOUR_DISTRIBUTION_ID \

  --distribution-config file://config.json \

  --if-match E2QWRUHAPOMQZL

Include this in config.json:

#  json

"Restrictions": {

  "GeoRestriction": {

    "RestrictionType": "blacklist",

    "Quantity": 2,

    "Items": ["CN", "RU"]

  }

}

twtech Notes & Best Practices

·        Country code format: Uses ISO 3166-1 alpha-2 codes, e.g., US, IN, CN.

·        Not 100% foolproof: Users can bypass restrictions using VPNs/proxies.

·        Per-request behavior: The restriction is applied before the origin request is made.

 

Project: Hands-on

How twtech enables geo restriction on its cloudfron distribution:

Select the cloudfront distribution to configure and click open: twtech-cloudfront-distribution

Go to security tab for: twtech-cloudfront-distribution

Navigate to cloudfront  geoprahic restrictions and: Edit countries

From: none

To:

Setup countries for:  Allow list

NB:

Any country not included in the allow list is automatically moved to the block list and vice versa

Save changes:

twtech insights:

twtech-insights:

 

The different between cloudfront price classes 200, 100 and all.

CloudFront Price Classes (100, 200, All) allow you to control costs by choosing which edge locations your content is delivered from. The fewer locations you use, the cheaper it can be — but possibly at the cost of slightly higher latency for some users.

 CloudFront Price Class Comparison

Price Class	Includes Edge Locations In	Use Case Example
Price Class 100	North America & Europe only	Cost-sensitive global sites targeting U.S./EU
Price Class 200	North America, Europe, Asia, Middle East, Africa	Broader global audience, balanced cost/performance
Price Class All	All edge locations worldwide	Lowest latency & best performance globally

 

 What It Actually Does

• Performance vs. Cost Tradeoff:
• Price Class 100: Uses fewer edge locations → cheaper, but higher latency for users far from NA/EU
• Price Class All: Uses all edge locations → lowest latency, but higher cost
• Behind the Scenes:
  CloudFront automatically maps requests to the closest location within your selected price class.

 Cost Difference (Indicative)

Region	Price Class 100	Price Class 200	Price Class All
U.S./EU	✅	✅	✅
Asia	❌	✅	✅
South America	❌	❌ (some)	✅
Australia	❌	✅	✅

❗ You are billed based on which edge locations served your content, not by which class you selected.

✅ When to Use Which

• Price Class 100:
  Best for cost optimization when twtech users are mainly in North America and Europe.
• Price Class 200:
  A good middle ground if twtech want better performance in Asia, Africa, and Middle East without paying for South America/Australia.
• Price Class All:
  Use when performance is a priority and twtech users are truly global.

How twtech Set PriceClass: CLI

In the AWS Console or via CloudFormation/CLI when creating or updating a distribution:

#  json

"PriceClass": "PriceClass_100"

Options:

• PriceClass_100
• PriceClass_200
• PriceClass_All