Multi-CDN Strategy: Benefits and Best Practices

What is Multi-CDN?

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A CDN (Content Delivery Network) is a network of geographically distributed servers that brings web content closer to where end users are located, to ensure high availability, optimized performance and low latency. Multi-CDN is the practice of employing a number of CDN providers simultaneously.

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This method augments the performance benefits of using a CDN while also ensuring redundancy and resilience and reducing costs.

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To implement a M-CDN, organizations can use traffic management tools or Multi-CDN switching solutions that distribute and route content across the various CDN providers.

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Distribution is dynamic and will be determined and optimized in real-time, based on factors like performance, geographic reach, costs, use cases, and real-time conditions.

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Benefits of a M-CDN

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There are multiple advantages for a Multi-CDN implementation. Some key advantages include:

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1. Network Redundancy

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The primary and most important advantage of a Multi-CDN strategy is redundancy, and, consequently, improved reliability. Outages are a common occurrence; a global outage could take the entire network down while local outages could force the CDN vendor to serve the traffic from a non-local PoP.

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The result would be a performance drop in the end users’ experience, often causing the application to become unusable. While these occurrences take place "only" a few times a year, local outages happen on a weekly, or even daily, basis.

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A M-CDN enables enacting a failover strategy with additional CDN providers that have not been impacted. This ensures up to 5-nines of availability, minimizes the impact of disruptions, enables meeting SLAs and reduces the risk of a single point of failure.

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2. Enhanced Performance

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Another significant advantage of using multiple CDN providers is the improved content delivery performance for end users. Different CDN providers cover different regions to different extents.

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When using a single CDN, the organization is dependent on the CDN provider’s geographical coverage and server infrastructure. This coverage may not align with the organization's needs at all times.

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Distributing content across multiple CDNs allows switching to the CDN with the best coverage and lowest latency for each user at any given time. This will result in faster load times that improve the user experience.

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3. Cost Optimization

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M-CDN setups can help optimize content delivery costs. This is done by selectively choosing when to use different types of CDNs. While high premium CDNs provide a full set of features - including security services, edge computing and more - these come at a high cost.

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Standard CDNs, on the other hand, provide a more basic set of features, but at a lower cost. Organizations can use premium CDNs for critical tasks while cutting costs when performing simple or lower priority tasks by using standard CDNs.

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In addition, different CDN providers offer competitive pricing models and packages. Organizations can select the most cost-effective option for each region or traffic type, reducing overall CDN expenses.

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4. Flexibility

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Multi-CDNs enable network professionals, IT, and DevOps teams to maximize the benefits offered by different CDN vendors. They provide flexibility in pricing by allowing the selection of the serving provider in specific areas or for specific portions of the traffic.

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The multi-vendor approach also allows leveraging the unique capabilities, such as unique Edge Computing functionality, offered by different providers. This flexibility provides customers with more control, increased bargaining power, and prevents them from being locked into a specific provider.

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Best Practices for Implementing a Multi-CDN

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While the advantages of a M-CDN are clear, implementation is not as straightforward. A cautious approach is crucial when transitioning to a M-CDN architecture.

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The configuration of new CDNs is intricate and prone to errors. Even minor misconfigurations can lead to disruptive traffic interruptions.

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To ensure a smooth transition, it is highly recommended to take the following best practices:

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1. Cherry Pick Your CDNs

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Conduct a thorough evaluation of different CDN providers. Consider factors such as geographic coverage, server infrastructure, performance, CDN scalability, pricing models, features, and support services. Evaluate how well each provider can meet your specific requirements and objectives.

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Narrow the final choice down to two providers, run a POC and A/B test them over the course of a few weeks to determine which one can best answer your requirements.

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2. Configure Your New CDN

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To effectively configure your new CDN, you need to replicate the settings of your primary CDN.

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Each role, policy and behavior needs to be manually and meticulously configured to align with the new CDN's engine, utilizing its API.

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Then, rigorous testing is necessary to ensure it functions properly. Otherwise, the result may be a deteriorated user experience, traffic loss and service unavailability.

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3. Transit the Traffic Safely and Gradually

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Once the CDN is configured, it’s time to proceed with a seamless and uninterrupted traffic transition that is based on Multi-CDN switching.

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It is recommended to employ an active/active strategy in a gradual manner. Begin by directing a small portion of the traffic to the new CDN.

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Progressively increase the volume of traffic being routed through it until the desired level is reached and you can rely on real-time switching.

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4. Implement Traffic Management Tools

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Utilize specialized traffic management tools or solutions to implement and manage your M-CDN effectively. Implementing such tools simplifies the management of a complex Multi-CDN environment.

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These tools can help automate traffic routing, monitor performance, collect data for analysis, and dynamically adjust traffic distribution based on real-time conditions. Make sure to never starve a CDN vendor - always keep all vendors with a portion of the traffic to keep the cache warm.

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Many organizations use a DNS switching service, which routes traffic between the different CDNs. However, this method can become too rigid when conditions are dynamic, as it does not adjust levels of traffic according to changing needs.

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A DNS switching service also does not provide visibility into the traffic, making traffic management challenging and less accurate.

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How a Virtual Edge Solution Handles This

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Virtual Edge solution, a technology developed by IO River, provides visibility into traffic while enabling traffic routing management through a single interface.

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A Virtual Edge also simplifies the CDN configuration process by enabling IT, DevOps or network professionals to configure the CDN only once, and without having to manually configure each one.

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Traffic can then be safely and gradually rerouted. In case of an error, a Virtual Edge solution also enables reverting to the previous configuration easily and quickly.

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5. Monitor and Optimize Performance and Availability

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Continuously monitor the performance of each CDN provider and the overall M-CDN setup. Use real-time analytics and monitoring tools to detect any downtime and outages and to gather metrics like response times, latency and availability.

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Analyze this data to identify areas where you can improve and optimize traffic distribution for optimal performance.

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6. Implement Failover and Redundancy Mechanisms

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Failover and redundancy mechanisms can help ensure high availability and reliability. Define backup plans and strategies to automatically reroute traffic in case of CDN provider outages or performance issues.

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This helps minimize service disruptions and ensures consistent content delivery to end users. Avoid any manual failover plans - they fail to execute when you need them.

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‍Edge Computing and Mobile Edge Computing in Multi-CDN Architectures

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Let's face it - delivering content quickly isn't enough anymore. Today's users expect personalized, responsive experiences no matter where they are or what device they're using. 

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That's where Edge Computing (EC) and Mobile Edge Computing (MEC) need to be paired with your multi-CDN strategy:

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Edge Computing in Multi-CDN Environments

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Think of Edge Computing as your multi-CDN setup on steroids. Instead of simply storing content closer to users, you're actually running code and processing data right at the edge. 

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This opens up some pretty exciting possibilities:

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• You can generate dynamic content on the fly without the dreaded round trip to your origin servers. Those personalized product recommendations or location-specific offers happen instantly, right where your users are.
• Your central servers get a much-needed break. By offloading processing to the edge across multiple CDNs, your origin infrastructure doesn't have to work nearly as hard. This means better scalability when traffic spikes hit.
• Real-time applications become genuinely real-time. Whether it's gaming, live streaming, or interactive tools, the processing happens so close to users that they'll never notice that lag that drives them crazy.

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Mobile Edge Computing for Better Mobile Experiences

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Mobile Edge Computing specifically tackles the challenges of delivering exceptional experiences to users on cellular networks:

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• With 5G rolling out everywhere, MEC helps you actually deliver on the promise of lightning-fast mobile experiences by integrating with multiple CDN providers that are optimized for these high-speed networks.
• Location really matters for mobile users. MEC gives you the smarts to route traffic through the perfect CDN based on exactly where someone is standing and what the network conditions are like in that precise spot.
• If you're supporting thousands (or millions) of IoT devices, a combined MEC and multi-CDN approach gives you the distributed infrastructure to handle all that data without overwhelming any single point in your network.

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Making It Work in Real Life

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Adding Edge Computing to your multi-CDN setup isn't something you do overnight, but it's worth the effort. Here's what to keep in mind:

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1. Not all CDN providers offer the same edge capabilities. Some have basic functions while others let you run complex applications. Match your needs with what each provider does best.
2. Keep your code consistent across providers. Nothing's more frustrating than features that work through one CDN but break through another.
3. Think about how data stays synchronized between edge nodes. You need the right balance between consistency and performance.
4. Don't forget security - it needs to be rock-solid across your entire edge network, regardless of which CDN provider is handling the traffic.

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Next Steps for IT Infrastructure, Network and DevOps Leaders

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A M-CDN can be very beneficial for your organization, ensuring your traffic is always optimized and all global users get first-class citizen treatment.

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Realistic Implementation Timeline

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Most organizations can expect the following timeline:

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• Assessment & Planning (4-6 weeks)
  
  • Define requirements and KPIs
  • Evaluate potential CDN providers
  • Design architecture and routing strategy
• Provider Selection & POC (2-4 weeks)
  
  • Run limited tests with selected providers
  • Validate technical compatibility
  • Benchmark performance
• Initial Configuration (2-3 weeks)
  
  • Set up primary configurations
  • Implement monitoring tools
  • Establish baseline metrics
• Gradual Traffic Migration (4-8 weeks)
  
  • Start with non-critical traffic
  • Incrementally increase traffic volumes
  • Monitor and optimize continuously
• Optimization & Fine-tuning (Ongoing)
  
  • Analyze performance data
  • Adjust routing rules
  • Optimize cost efficiency

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When you begin the transition, make sure to take it slowly and implement the new setup gradually. It is also recommended to have experienced professionals accompany you throughout the process. They will help you avoid any mistakes and ensure you and your users can benefit from the reliability and improved performance a Multi-CDN can provide.

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To learn more about IO River, the most advanced Virtual Edge solution for your Multi-CDN strategy, click here.

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FAQs

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1. How Does a Multi CDN Solution Improve Website Performance? 

A multi CDN solution improves performance by dynamically routing traffic to the fastest provider for each user's location. When a user requests content, the system selects the optimal CDN based on real-time performance metrics, geographical proximity, and network conditions. This intelligent routing ensures faster load times, reduced latency, and smoother user experiences across all regions, delivering up to 40% performance improvements compared to single-CDN setups.

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2. What Metrics Should Businesses Monitor in a Multi CDN Setup? 

Businesses should monitor both performance and availability metrics across all CDN providers. Key performance indicators include Time To First Byte (TTFB), throughput rates, cache hit ratios, and origin shield effectiveness. For availability, track error rates, HTTP status codes, and traffic distribution patterns. Advanced multi CDN solutions provide unified dashboards that consolidate these metrics, enabling real-time performance comparisons between providers and facilitating data-driven routing decisions.

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3. How Do Multi CDN Providers Handle Regional Traffic? 

Multi CDN providers specialize in optimizing regional traffic through strategic Point of Presence (PoP) placement and regional routing intelligence. Each provider typically has geographic strengths where their infrastructure excels. A well-implemented multi CDN strategy leverages these strengths by routing traffic to the provider with the best performance in each region. This region-specific optimization ensures users receive content from the most efficient source regardless of their location, eliminating the "coverage gaps" inherent in single-provider solutions.

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4. How Can Multi CDN Solutions Help Mitigate Downtime? 

Multi CDN solutions provide automatic failover capabilities that virtually eliminate downtime. When one provider experiences issues, traffic automatically reroutes to healthy alternatives within seconds. This redundancy ensures continuous service availability even during major outages. Organizations implementing proper multi CDN architectures can achieve up to 99.999% uptime (five nines reliability), representing less than 5.26 minutes of downtime annually, compared to 99.9% (three nines) or approximately 8.76 hours of downtime with single-provider setups.

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5. What Are the Cost Implications of Using Multi CDN Providers? 

While implementing multiple CDN providers may initially seem more expensive, the strategic approach often delivers cost savings. Organizations can negotiate competitive rates with multiple vendors, implement cost-based routing during non-critical periods, and optimize traffic distribution based on pricing models. Additionally, the reduced downtime and performance improvements translate to revenue protection. Most organizations report 15-30% cost optimization after implementing sophisticated multi CDN strategies that balance premium and standard CDNs based on content criticality and business requirements.

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