Single vs. Multi CDN: Pros, Cons, Technical & Operational Considerations
CDNs are crucial for user experience and your reputation
Being around for a long time, CDNs are now an essential part of modern Internet service. A CDN helps a content owner deliver content at high speeds. This is done as a distributed system, where different servers are deployed in different datacenters worldwide and share the same network path between them. Many organizations are entering the CDN industry as businesses realize the importance of CDNs.
The Internet is becoming very important, and relying on one CDN is becoming a liability. Compromise of the Internet, either by attack or security failure, could lead to financial loss for a company. Instead of placing the company’s trust and reputation in one CDN, it is better to spread the workload among multi-CDNs. This is due to the high failure rate of single CDNs. There is no way to know if one of them will go down and cause a considerable disruption of services.
Diverse content and sites are being added daily, so managing all this content within one location becomes difficult. Businesses want to use Multi-CDNs, while also retaining the benefits of single content delivery across their domain.
What is Multi-CDN?
Multi-CDN is a complementary solution for content delivery networks. This system distributes a site’s content over several different CDNs to ensure that each delivery system has enough capacity to deliver the content. Multi-CDN works by dividing the workload into smaller pieces and distributing them among multiple CDNs. It can also increase network redundancy and reduce downtime due to network issues. If one of the CDNs goes down, Multi-CDN will remain operational enough to handle additional requests.
A Multi CDN is a system that uses multiple CDNs from different service providers as a single network. This solution can help reduce the number of websites that prompt loading errors, and it can help achieve better performance for a website than in a single CDN system.
No CDN offers universal coverage, so relying on multiple providers increases the reliability of CDN delivery by permitting broadcasters to provide more widespread coverage. Multiple CDNs also give your PoPs a more comprehensive array of providers.
With additional distribution, your video can reach regions where individuals can locate it. You can also set up an alternative support system if your network provider’s servers become overloaded or offline.
How Multi-CDNs work
Multi-CDNs work by directing traffic to different CDNs in the network. In multi-CDN implementations, the specific criteria for making routing decisions differ. Some common multi-CDN strategies include:
- Static DNS: With this setup, static IP addresses can be configured for several content delivery networks (CDNs) in a multiple-CDN setup. For instance, high-speed video streaming traffic may be sent to StackPath’s CDN and access static downloads to another CDN.
- Managed DNS: Managed DNS services add more intelligence to traditional DNS solutions. Smart DNS minimizes the manual work required in directing web traffic and improves fault tolerance. Cost and performance variables do not play into route choices when using smart DNS like static DNS.
- Round-Robin: A round-robin solution to multi-CDN routing fluctuates according to the next one in the line. For example, in a two CDN setup, the one with the higher score will handle request number one, the one with the lower score will handle request number two, etc. A weighted round-robin allows one to control the route based on users’ requirements.
- Geolocation: In the case of a multi-CDN, geolocation is used to determine which CDN to use based on the user’s location. The CDN with the closest PoP to the user will respond to each request.
- Variable-Driven Load Balancing: Multi-CDNs integrated with variables like cost, performance, location, weights, and other variables, so interactive are the best to configure, though the challenges associated with them will also be high. By accounting for multiple guidelines in real-time, real-time load balancing makes it possible for globally-distributed networks to function with cost-effective performance. It also applies to proportionally sized networks.
Pros and Cons
- Redundancy: Redundancy is the most significant advantage of using multiple CDNs. In the case of a failure, the other providers in the network will pick up where they left off. This helps prevent users from loading errors and other performance issues that an outage could have caused.
- Resilience: Resilience is an attribute of the system that helps prevent a failure in one part of the network from affecting the whole system. If a single CDN fails, other CDNs can pick up the slack. Multi-CDN systems also aim to increase resilience by using different providers within the network. Even though every provider has technical issues, latency and performance issues will be distributed among providers, so your users will not experience significant degradation from using multiple CDNs.
- Performance: A Multi CDN will give your users the best performance. In this type of network, you can reduce the wait time they experience while using your website. The content delivery network (CDN) will be able to handle more traffic and deliver content quickly because it has three different networks in place.
- Reliability: Reliability is the ability of a system to perform its required functions and provide consistent service in an environment where there are redundant resources. Using a Multi-CDN will make your network much more reliable for the users. Multi-CDNs work by increasing the number of servers that serve content, so if one provider experiences problems, your content will be hosted elsewhere. This will not disrupt the service, and it will let users spend less time looking at loading pages.
- More Complex Infrastructure: Multi-CDNs are complex and require more server resources. The additional servers mean more hardware and software issues. Also, the more providers you use, the higher the possibility of conflicts and lower efficiency.
- Can Be Costly: Multi-CDN systems are expensive because they need to have a lot of PoPs in place to help with redundancy. You need to purchase new hardware or rent server space from your existing provider or another company you may choose to buy out.
- Inflated Number Of Vendors: Using a multi-CDN structure can lead to more vendors, which is more challenging to handle and control. Adding more providers will increase the risk of potential security breaches because too many people are accessing your data.
Multi-CDNs are primarily used by businesses that can handle the additional complexity and cost. Each step of configuring Multi-CDN will result in a tradeoff between security, latency, availability, ease of implementation, and the existing infrastructure. Therefore, it is essential to weigh the prospective benefits of implementing a Multi CDN strategy before deciding. Before implementing a Multi CDN strategy, here are some questions to ask yourself:
- How much of the content is cached? How many CDNs are you going to use? What is the capacity of each vendor? How much storage space do you have for each vendor? Are there redundant copies of resource data for each CDN provider?
- How much traffic is there on your website? Where is the traffic coming from (PC or mobile devices)? What is the average latency from the client to the content source (internal server or CDN)? Do you have any direct access to the content source, or do you have?
- Can you allow downtime, and what is the financial impact? What will be the impact on users? Can you implement this system automatically? Do you have the technical capability to do it automatically?
- Can you effectively manage a multi-CDN architecture with existing tools? How can your team or business manage the cost and complexity of this architecture?
- Who will be managing various vendors, who are responsible for technical support, and how will you stay updated with vendor offerings and changes in technology?
- How can you efficiently transfer users between the vendors and ensure performance enrichment across all providers? How will you protect against an empty page once the user has switched between providers?
- How difficult is it to upgrade a vendor, and what will be the cost of doing so? Will a Multi-CDN system.
Most CDN resellers do not offer a managed multi-CDN service, as they are only partnered with a single vendor. But GlobalDots is one of the few multi-CDN resellers. GlobalDots is partnered with all the major providers to provide the most comprehensive coverage for your CDN needs. Provide you with a cost-effective plan of 2-4 CDN vendors, including a daily report and the possibility of adding new vendors every month.
Provide you with a dedicated and insightful dashboard on your observability platform to monitor and measure the performance of your CDN architecture. And provide you with configurations as code that allow simultaneous changes to all CDNs at a single action to ensure that sound changes are implemented rapidly.
In conclusion, a Multi-CDN architecture is recommended for any online business wishing to expand its reach and improve service. Having a multi-CDN vendor network in place will allow companies to be more agile and flexible in the short term by adding capacity at any time. However, if there isn’t a dedicated in-house function to manage this architecture, it’s necessary to turn to a CDN-specialized technology partner who might offer this managed service. A good technology partner should give you lower pricing per GB and overall cost efficiency than a single CDN and save you the need to configure yourself for cost or performance optimization. GlobalDots helps you leverage your CDN investment by allowing you to optimize your existing assets and by keeping you ahead of the competition.
Contact us today to learn more about our managed multi-CDN solution.