DNS outage (DNS downtime) – what does it mean? 

The DNS outage (a.k.a. DNS downtime or DNS failure) is a period of time when the domain name can’t be resolved to its IP address. The clients will send a DNS query for a domain name, but the DNS recursive will either answer with the old IP address from its cache, which will not respond, or it will try to query the DNS authoritative name server of the domain name won’t get an answer. 

What causes DNS outages? 

DDoS attacks

DDoS or a denial of service attack, is a type of cyber-attack that involves multiple devices that work together, targeting a victim’s computer, with a large amount of traffic intending to make it unable to answer any more queries. To prevent any problems that a DDoS attack can cause, you will need a load balancing that can share the traffic between your servers, even if it is very strong. And also, you will need DDoS-protected servers. 

Maintainance of the authoritative name server

If you are using only one authoritative name server, whatever happens to it, can affect your DNS. If it needs updates and reboot, the time that it takes, the server won’t be able to respond to DNS queries. Updates and maintenance are needed, so you better have a Secondary DNS that can answer the queries meanwhile. 

A problem in the data center, where the authoritative name server is

The cloud equipment does not magically hover over the Earth. Instead, it resides in multiple data centers. These places can have problems like long-lasting electricity outages, natural disasters affecting the area, fire, or other problems. If you are using a cloud service, these issues are out of your hands, but you can use multiple servers in multiple data centers. If one is down, still, there will be more to answer the queries. 

Bad configuration

Errors in DNS configuration can cause DNS downtime. It can be a human mistake, like badly addressing caused by misspelling the IP address or domain name, script error, wrong firewall configuration, etc. 

If it is a misspelled problem, you can try to query the domain name and the IP address to see which does respond and which does not. 

If it is the firewall, you can check the ports if they were allowed. 

DNS propagation delay

When you add or remove DNS records (like A or AAAA records), the changes are not always instant. You are editing the zone file inside the Primary DNS server, and you can propagate to your Secondary DNS servers, but there are many DNS recursive servers that you don’t control. They can keep your old IP address and provide it to clients, even after you published a new one. 

What you can do about the DNS propagation is to push the zone transfer to your Secondary servers and to keep lower TTL values for your DNS records. 

It is not technically a DNS outage because it will affect only those with the older cached IP address of the domain name, but it was worth mentioning it.

How to avoid DNS downtime (outage)

The best way to avoid DNS outages is to have a robust DNS network that provides redundancy and can withstand strong traffic. The more servers you have, the better you are going to be prepared. Additional features might also facilitate the DNS administration and automate the process of handling problems. 

Use Secondary DNS services

A secondary DNS service provides you with the opportunity to use multiple Secondary DNS servers, which can be set as Secondary authoritative nameservers. They will have a copy of the zone file with the DNS records. They can answer queries for your domain, just like the Primary one. The big advantage is that they will keep answering even if the Primary is experience downtime. Having Secondary DNS is your DNS backup solution. 

You can learn more about it in this article, “What is backup DNS?”, and you can try our Secondary DNS plans with a 30-day free trial. 

Use DNS load balancing

DNS load balancing is also another nifty way to lower the chance of DNS outages. It is a mechanism for administrating the DNS traffic between the DNS server, based on criteria like the number of active connections, specific algorithm, time of connection, etc. 

It will reduce the stress on a particular DNS server and spread it between the network. 

It can help in case of a DDoS attack but also in a natural spike in traffic caused by increased clients’ queries. It can help you during a promotional period when you are experiencing higher traffic.

Be prepared with DNS Failover

DNS Failover is a trigger that will activate in case of a nameserver’s failure. It can automatically redirect the traffic without any human interaction, based on the information it gets from DNS monitors like ICMP ping, UDP requests, HTTP checks, etc. It is an easy way to keep your clients’ happy and provide DNS resolution, even if some of your DNS servers are experiencing some problems. We offer DNS Failover service with all of our paid plans.

Also, we recommend you to check our Brand new Monitoring service!

How to diagnose DNS outages?

When facing a DNS outage, quick diagnosis is essential to restore functionality. Follow these steps to pinpoint the problem:

• Ping the Domain

Use ping to check if the domain resolves and the server responds.

ping example.com

If it doesn’t resolve, it’s likely a DNS issue.

• Test DNS Resolution with nslookup

Verify if DNS is working by querying your DNS server with nslookup.

nslookup example.com

If it returns an IP address, DNS is working for that domain. But if it fails, the DNS server may be down or misconfigured.

• Run dig for detailed queries

Use dig for detailed DNS resolution data, including specific DNS record types.

dig example.com

Add +trace to follow the query path through name servers and find where it fails.

• Test with Alternate DNS Servers

Query public DNS servers (like Google’s 8.8.8.8) to rule out provider-specific issues.

nslookup example.com 8.8.8.8

If the domain resolves with a different DNS server, it suggests the problem is with your original DNS provider.

• Check DNS Propagation Delays

If you’ve recently made DNS changes (such as updating A or MX records), delays in DNS propagation could be the culprit. Use online tools like ClouDNS Free DNS tool to check whether your DNS records have propagated across global DNS servers.

• Check for DDoS attacks or high traffic loads

DNS outages can be caused by Distributed Denial of Service (DDoS) attacks or heavy traffic loads. Tools like TCPdump can help capture and analyze DNS traffic to detect abnormal patterns, such as a flood of queries or unusual IP activity.

Example:

sudo tcpdump -i eth0 port 53

This command captures DNS traffic, allowing you to inspect for signs of an attack. For real-time detection, combine TCPdump with network monitoring tools and DDoS mitigation services.

Troubleshooting 

What can you do when your domain is not reachable? 

As DNS administrator of the domain name, you can: 

• Suppose you have recently finished a DNS delegation. You might need to way up to 24 hours, so the changes are well propagated. 
• Check if you have paid for your domain name. If you have forgotten to pay your domain name, it won’t answer queries anymore when it expires. Set reminders for domain renovation and don’t miss the time. 
• Use the ping command to ping the DNS server from different locations to see if it is responding to any DNS requests. It is possible that you haven’t set up your nameservers correctly, and they are working but not answering queries for the domain name. 
• Try to reach the DNS server by using its IP address. If you can reach it, there might be a badly configured A or AAAA record that does not link well the domain name and its IP address. 
• Check your DNS monitor and see how the traffic is going. If you can’t see the monitor’s log, check if there were any unusual activities before the server stopped working. For example, it could have been a DDoS attack. If it is still happening, you can redirect the traffic and stop it. 

As a client who can’t reach a site: 

• You can have problems with the DNS cache of your device. You can flush the DNS of your device and your browser. This action will remove the previous DNS records that you have, and your device will search again for the A or AAAA record of the site you want to visit. If you had an older IP address, this could fix it. 
• Maybe your router is the problem. The router has a recursive DNS server that may need to be restarted. Pull its plug, then wait around a minute and connect it again. It should reboot and start working well again. 

Monitor your DNS server

Monitor your DNS for any strange pattern in traffic. There are different automatic monitors that you can set to see the traffic behavior. If something strange happens, you can see in almost real-time any changes and use the information to take action. 

You can monitor the DNS from different locations. That way, you can see if the problem is very local, is it regional, continental, or global. It will be easy to spot the problem.
DNS monitoring works best in combination with DNS Failover. You can set the monitor with the parameters that you prefer, and it will notify you and show you the data. But when you also have DNS Failover, you can connect this data and trigger automatic even in case of a down server. It can deactivate DNS records and replace them with working. It can also react in case the server gets up and add it to the list again. 

ClouDNS offers DNS Failover service for all of its paid customers. You can set it up and activate it for your domain fast and easily.

What are the consequences of a DNS outage?

If a DNS outage occurs, it could have a negative impact on your entire organization and community of customers. When DNS (Domain Name System) is down, websites, applications, and online services related to the domain name, such as emails, won’t function correctly. Unfortunately, that has the potential to damage operations, revenue, and brand reputation. In addition, you should act fast and quickly get it up and running again to regain all the temporarily lost functionality.

Yet, let’s assume the functionality of the DNS operations was seriously interrupted for a prolonged period of time. In that case, a DNS outage can potentially cause devastating consequences to the companies with an online presence. Here are some of the most common effects during this time: 

• Miss potential visitors
• Lose potential sales
• Have issues with services like email, FTP, VoIP, etc.
• Productivity losses
• Damage to reputation
• Impact on customers and strategic partners
• Diminished competitive advantage

It is crucial to implement all precautionary measures to avoid DNS outage’s negative influence on your business.

The biggest DNS outages in the history

• 2016 Dyn DNS Interruption: A significant disturbance shook the internet when Dyn, a leading DNS service provider, fell victim to an attack. Websites with heavy traffic, such as Twitter, Spotify, and Reddit, experienced outages. This event underscored the vulnerabilities tied to unsecured IoT devices.
• 2019 Cloudflare Outage: A misconfigured web application firewall rule caused a major disruption in Cloudflare’s services, impacting millions of websites.
• 2019 Google Cloud Outage: In June 2019, Google Cloud Platform experienced a significant outage that affected multiple services, including Gmail, YouTube, and Google Cloud Storage. A configuration change intended for a small number of servers in a single region was mistakenly applied to a larger number of servers across several neighboring regions.
• 2020 AWS Outage: In November 2020, Amazon Web Services (AWS) faced a significant outage that affected several services reliant on AWS’s infrastructure. This incident disrupted many online services and platforms, highlighting the vulnerabilities in centralized cloud infrastructures.
• 2021 Fastly Global Outage: In June 2021, a major global internet outage occurred, affecting numerous high-traffic websites including Reddit, Twitch, and even the UK government’s official website. This was traced back to a software bug in the Fastly CDN network, a critical infrastructure provider for many internet services.
• 2022 Microsoft Azure DNS Outage: In mid-2022, Microsoft’s cloud service, Azure, experienced a DNS outage. It impacted a wide range of services, from basic operations in Azure to third-party applications relying on Azure’s infrastructure. The outage underscored the need for robust failover systems and redundancy in cloud services.

Conclusion

A huge DDoS attack can lead to a DNS outage even if you have excellent infrastructure. But applying all the measurements can lower the time and the frequency of the DNS outages. Be prepared and intelligently manage your DNS traffic to be able to provide excellent service for your clients. Keep your business up!

The post What is a DNS outage (DNS downtime), and how to avoid it? appeared first on ClouDNS Blog.

What is Round Robin Load Balancing?

Round Robin Load Balancing is a simple technique for spreading incoming traffic across multiple servers. It cyclically forwards client requests via a group of servers to effectively balance the server load. It is excellent in cases when the servers are very similar in their computational and storage capacities. 

Round Robin Load Balancing is most commonly used because of its simplicity. Its implementation is rather straightforward. It is a distributor that redirects the traffic from different users to the servers in order. Let’s see an example. Imagine you have 6 users (u1, u2, u3, u4, u5 and u6) who want to connect and you have 3 servers (s1, s2 and s3). U1 will connect to s1, u2 to s2, u3 to s3 and it will start all over again u4 to s1, u5 to s2 and u6 to s3. Can you guess to which will it connect the next user 7? Yes, it will connect to s1.

It takes into account just when somebody wants to connect. Nothing more. It will definitely serve as a load balance, based on this logic, but ignore all other parameters. So you will have reduced load on the network, but you can have different problems.

Maybe your servers are not equal. Imagine server 1 (s1) is a lot faster than the rest. With more RAM, better CPU, etc. It will still receive the same traffic as the rest which are weaker. It is not the most efficient scenario. For that reason, Round Robin Load Balancing works best with the same configuration of servers.

How does Round Robin Load balancing work?

Round Robin Load Balancing functions under a very easy-to-understand mechanism. As we mentioned earlier, this technique forwards requests cyclically between servers. They are sequenced depending on the order they arrive. This mechanism is especially helpful during high incoming traffic and keeps the load balanced. 

Here is an illustration of how Round Robin Load Balancing actually works. Let’s imagine a company that holds a group of four servers: A, B, C, and D, and many users send requests to connect with their website:  

• Server A gets request 1
• Server B gets request 2
• Server C gets request 3
• Server D gets request 4

The rotation starts all over again when the load balancer continues to send requests to servers. 

But what if one of the servers has the capacity to handle more requests compared to others? Then you can implement Weighted Round Robin (WRR)!

Weighted Round Robin (WRR)

Weighted Round Robin is a little bit more advanced configuration for balancing the load. Yet, it is a perfect opportunity if one of your servers has better characteristics than the rest. The administrator can assign weight to every server in the group based on chosen criteria. In a most popular scenario, the criterion is the server’s traffic‑handling capacity.

This variation of Round Robin takes into account the previous case, where one server is better than the rest. Imagine the s1 is twice more powerful than s2 and s3. We will assign it higher weight because it can handle a more significant load. Because we did this, it will get more traffic.

Following the example, u1 will connect to s1, then u2 will again connect to s1. This is the main difference. U3 will connect to s2, u4 to s3, then again u5 to s1 and u6 to s1. U7 will connect to s2.
There is another scenario where Weighted Round Robin can be useful. Maybe your servers are similar, but you have more important information in one, you want it to have less weight. So, it that case you assign higher values to the rest of the servers. This way they will handle more load and your essential server will have less work and less chance to crush.

Suggested article: What is Load Balancing?

Advantages and Disadvantages

Round Robin is a simple and widely used load balancing algorithm that distributes incoming network traffic across a group of servers. Like any other method, it has its own set of advantages and disadvantages. Here are the main benefits and drawbacks of the Round Robin Load Balancing mechanism:

Advantages

• Simplicity: It is an easy-to-understand and easy-to-apply technique. Additionally, it does not require much effort to set up, works on a clear mechanism, and has an uncomplicated framework.
• Even Distribution: It provides a relatively even distribution of incoming requests across the available servers. Each server gets an equal share of the load, which is beneficial when all servers have similar processing capabilities.
• Low Latency: Round Robin is generally low in terms of latency because it doesn’t involve complex decision-making processes. It simply follows a predictable rotation.
• Scalability: Round Robin is easy to scale horizontally. When you add more servers to your pool, they can be smoothly integrated into the rotation without major reconfiguration.

Disadvantages

• Deficiency of functionalities: The simplicity of this mechanism is also its main drawback. Many experienced administrators prefer to utilize Weighted Round Robin or more complicated algorithms. 
• Lack of Intelligence: Round Robin doesn’t consider the actual load or health of individual servers. It treats all servers as equal, which can be problematic if some servers are underutilized while others are overloaded. This can lead to inefficient resource allocation.
• Stateless Nature: It’s a stateless algorithm, meaning it doesn’t consider the current state of the server (like CPU load or memory usage). This lack of awareness can lead to not-so-optimal performance.

Can I use Round Robin Load Balancing with ClouDNS?

Yes, you can use Round Robin Load Balancing with ClouDNS. It is an included feature in both paid and free plans. You can easily sign up for a free account.

Here’s how you can use Round Robin load balancing with ClouDNS:

1. Register your domain with ClouDNS: If you haven’t already, register your domain with ClouDNS or transfer your existing domain to our DNS service.
2. Create DNS records: In the ClouDNS control panel, you can easily create DNS records. For Round Robin load balancing, you can use A records, AAAA records and ALIAS records, but you can’t use CNAME records with any other DNS record for the same host.
3. Set TTL values: Configure the Time to Live (TTL) values for your DNS records. TTL determines how long DNS resolvers should cache the DNS records. 
4. Regularly update DNS records: If you need to add or remove servers from the load balancing pool, you can do so by updating the DNS records in the ClouDNS Control Panel.
5. Monitor and optimize: Regularly monitor the performance of your load balancing setup and make adjustments as necessary to ensure that traffic is evenly distributed.

If you have any additional questions, you can contact our 24/7 Live chat support!

When to Use Round Robin Load Balancing

Round Robin Load Balancing is ideal for scenarios where all servers in the pool have similar resources and capacity. It is well-suited for small to medium-scale applications where even traffic distribution is the main concern. For example, small businesses with limited servers can effectively use this method to ensure their websites or applications stay responsive and balanced under normal traffic conditions.

However, if your infrastructure has servers with varying performance levels or inconsistent resource availability, more advanced load balancing algorithms like Weighted Round Robin or Least Connections may be necessary. Understanding when to use Round Robin is key to optimizing its efficiency in your particular setup.

Round Robin vs. Other Load Balancing Algorithms

Round Robin is just one of many load balancing algorithms. Depending on your needs, other methods may be more suitable:

• Least Connections: This algorithm directs new requests to the server with the fewest active connections, which can help ensure better resource utilization when server loads vary significantly.
• IP Hash: This method directs traffic based on the client’s IP address. It ensures that each client consistently connects to the same server, which is beneficial for maintaining session consistency.
• Weighted Least Connections: This approach combines the advantages of Least Connections and Weighted Round Robin, ensuring that more powerful servers handle more connections while still considering their current load.

Common Use Cases

Round Robin Load Balancing is commonly used in the following scenarios:

• Web Hosting: Distributing web traffic evenly across a set of identical servers to balance the load and prevent any one server from becoming overwhelmed.
• Content Delivery Networks (CDNs): In some CDN setups, Round Robin Load Balancing can be used to distribute content requests across different servers in the network, helping to ensure faster delivery.
• E-commerce Websites: Small to mid-sized e-commerce sites may use Round Robin to distribute user sessions across multiple servers, ensuring that no single server handles too much traffic during peak shopping times.

Conclusion

Round Robin Load balancing is a fundamental technique for distributing network traffic efficiently across multiple servers. It offers a simple and easy-to-implement method for ensuring optimal resource utilization and high availability. By cyclically assigning incoming requests to servers in a sequential manner, Round Robin helps prevent overload on any single server, facilitating fault tolerance and load distribution. While it may not consider server health or actual load, it serves as a cost-effective solution for basic load distribution requirements. However, for more complex scenarios, advanced load balancing algorithms may be preferred. Finally, Round Robin Load balancing remains a valuable tool in the arsenal of network administrators.

The post Round Robin Load Balancing. Simple and efficient appeared first on ClouDNS Blog.

Load Balancing – Definition

The network performance has become incredibly important. No matter if your organization is big or small, you don’t want to experience operational issues or network reliability problems. Load Balancing manages the demand by distributing the traffic and the application load over different servers depending on their current load.

It is not a new invention. In its early days, it was used between the end device and the application servers to check the servers and to send traffic to the least occupied.

But with the evolving of the networks, load balancing has gotten a new shape. Now it is not a simple distribution system. The load balancing has become very divided.

Here are some Load Balancing examples:

• There is application load balancer which distributes one single application over the servers; there is another which distributes only between the server cluster; another directs the traffic from multiple paths to a single destination.
• Other load balancing solutions are very advanced. They can shape the traffic and act as intelligent traffic switches, do different health checks on the content, applications, and servers, add extra security on the network and protect it from malicious software and improve availability.

Choosing load balancing is hard. You need to think about the demands on your networks and servers. You need 100% reliability on every part. If one component fails, this can lead to downtime.

Why Do You Need Load Balancing?

Load balancing is crucial for optimizing the performance, reliability, and scalability of your online services. Without it, a single server could become a bottleneck, causing downtime or even crashes during periods of high traffic. Load balancing helps distribute traffic efficiently across multiple servers, reducing the risk of server overloads and ensuring uninterrupted service. It also enhances user experience by providing faster response times and higher availability. Furthermore, load balancers help protect your infrastructure against DDoS attacks by distributing malicious traffic across multiple servers. It is particularly important for businesses with high traffic volumes or mission-critical services, as it can help maintain uptime and performance consistency. Another significant reason for adopting this mechanism is its scalability. As your website grows, adding more servers is a standard solution to manage the increased traffic load. Load balancing enables this growth by ensuring that new servers are smoothly integrated into your system without affecting overall performance.

How does it work?

Load balancing is achieved and managed with a tool or application that is called a load balancer. Despite the form of the load balancer (hardware or software), its main goal is to spread the network traffic among different servers and prevent overloading. 

Here are several steps which explain how load balancing works:

1. Your website receives traffic. Once users reach your website, they send a lot of requests to your server at the same time. 
2. The traffic is spread toward the server resources. The load balancer (hardware or software) intercepts and examines every request. Then, it directs it to the most suitable server node.
3. Every server works with a reasonable workload. The server node receives the request. When it is able to accept it, the server notifies the load balancer that it is not overloaded with too many requests.
4. The server answers the request. In order to complete the process, the server sends the response back to the user.

Whenever a user request arrives, the load balancer directs it to a precise server. The process repeats for every request. Load balancers are responsible for deciding which server is going to receive a precise request. That is determined based on different techniques for load balancing.

Types of Load Balancing

There are three appliances of Load Balancing – Physical, Virtual and Cloud-based.

Physical Appliance

This is the most traditional approach. The load balancer is placed right after the firewall and before the server cluster. Now you can expect the balancer to include more advanced functions like a built-in firewall and to be the all-in-one gatekeeper of the network.

There are other subtypes to the Physical. Some load balancers serve as caching devices, others like SSL accelerators or ADCs.

They are all physically present in the same data center as the application servers. The benefits that they provide are easy controlled and easy to connect and form bigger structures.

The negative part is that they are costly, you need to buy a lot of hardware and software to control them and lack geographical distribution.

Virtual Appliance

In the previous appliance, the main accent was put on hardware; here we don’t have a specific hardware. It runs on a virtual machine. This virtual machine provides the environment where the load balancing software works. It is a lot easier to apply because it can run on different computer configurations. It is cheap as well, and you can buy less expensive servers; the focus goes on the software, not on the hardware; it is easier to back up.

As for disadvantages, we can mention the problem with choosing a virtualization platform, and patches and upgrades can sometimes hurt the system.

Cloud-based Load Balancing

This is a convenient and robust solution for bigger networks. It is based on the cloud, and there it handles the load balancing and other functions like failover.

It manages interruptions, network problems, and outages far better and it can easily redistribute the traffic. Some other benefits of using Cloud-based Load Balancing are:

• Speed – it significantly reduces the response times and reduces the load on applications and web servers.
• Security – at load balancer level, DDoS attacks can be blocked and prevented.
• Low starting cost – you don’t need to buy software, nor expensive hardware. It is a service that you choose based on your current needs, and it is easily upgradable.

If you want to manage your DNS traffic (DNS requests) more efficiently, you can implement Load balancing in one of the following ways:

• Round Robin DNS

Round Robin DNS is a technique of load distribution, load balancing, or fault-tolerance provisioning multiple, redundant Internet Protocol service hosts (e.g. Web server, FTP servers), by managing the Domain Name System’s (DNS) responses to address requests from client computers according to an appropriate statistical model.

Round Robin DNS is often used to load balance requests between a number of Web servers. You can find more information regarding Round Robin DNS and how to use it here.

• GeoDNS

The GeoDNS service allows you to redirect your customers to specific IPs (servers) based on their geographic location. The service allows you to build your own CDN or to load balance your traffic. It is more accurate and smart than the Round-Robin. You can also set up different websites for each geolocation region. You can find detailed information regarding GeoDNS here.

Load Balancing Benefits

Load balancing is all about improving the management of network traffic and making the user experience better. Therefore, the benefits it provides are the following:

• Scalability: If you notice a drop or spikes in your traffic, you can easily increase or decrease the number of your servers to satisfy urgent requirements. That way, you can handle sudden massive amounts of requests. They usually appear, for instance, during a promotion or holiday sales.
• Redundancy: When you have the ability to maintain your website on multiple servers, you can ensure excellent uptime. Relying only on one web server hides a lot of risks that will force your visitors to leave your website. Load balancing is key if you can’t afford downtime.
• Flexibility: Load balancing gives you the ability to redirect traffic from one server to another. So that way, you have the flexibility to perform your regular maintenance work without disturbing the normal operations of your website.
• Avoid failures: Load balancing can be very helpful for avoiding failures. It spreads large amounts of traffic to the available servers and prevents outages. You can manage the servers efficiently and precisely. It is best if they are distributed across several data centers.
• DDoS attack protection: Spreading traffic across servers is also valuable when protecting against Distributed Denial of Service (DDoS) attacks. Load balancing helps when a particular server gets flooded with malicious traffic by a DDoS attack. The traffic is forwarded to many servers rather than just one, and the attack surface is reduced. This way, load balancing eliminates single points of failure, and your network is resilient against such attacks.

Who can benefit from load balancing?

Here are the organizations and sectors that can benefit significantly from load balancing:

• Websites and E-commerce: Websites with high traffic, online retailers, and e-commerce platforms benefit from load balancing to ensure fast page loading, minimal downtime, and a seamless user experience.
• Cloud Service Providers: Companies offering cloud-based services rely on this technique to distribute workloads across servers, ensuring scalability and fault tolerance for their customers.
• Enterprises: Large enterprises use load balancing to evenly distribute network traffic across servers, preventing overloads, optimizing resource utilization, and maintaining system stability.
• Content Delivery Networks (CDNs): CDNs use the mechanism to efficiently deliver content to users, reducing latency and improving the delivery of multimedia, software updates, and web content.
• Gaming Industry: Online gaming companies utilize it to handle multiplayer game traffic, reduce lag, maintain game responsiveness, and ensure a smooth gaming experience.
• Healthcare and Telecommunications: Critical sectors like healthcare and telecom rely on load balancing for fault tolerance and high availability, ensuring that vital services remain accessible even during peak loads or server failures.
• Internet Service Providers (ISPs): ISPs can optimize network traffic, improving internet connectivity for their customers and efficiently managing the load.
• Government and Educational Institutions: These organizations employ load balancing to handle high volumes of traffic on their websites and online resources, ensuring accessibility and reliability.

Best Practices

When implementing the load balancing mechanism, it is important to follow the best practices, which are the following:

• Implement Health Checks

Always use health checks to monitor the status of your servers. Regular monitoring ensures that traffic is routed only to functioning servers, preventing requests from being sent to unresponsive or slow servers, which can negatively affect the user experience. Health checks allow your load balancer to automatically exclude problem servers and reintroduce them once they are back online.

• Select the Right Type of Load Balancer

Choosing the appropriate load balancer for your needs is key. Hardware, software, and cloud-based load balancers each offer different advantages. For small businesses, a cloud-based load balancer can offer flexibility and scalability, while enterprises with complex needs may benefit from physical or hybrid solutions. Consider your traffic type, load, and future growth when making a decision.

• Prioritize Redundancy and Failover Plans

Always ensure you have redundancy built into your load balancing setup. A backup or failover load balancer should be in place to take over in case the primary one fails. This ensures that traffic continues to flow smoothly even during server or network outages, thereby maintaining high availability for your users.

• Enhance Security

Load balancers are a frontline defense against Distributed Denial-of-Service (DDoS) attacks and other malicious traffic. By distributing traffic, they prevent bottlenecks that attackers aim to exploit. Implement DDoS protection strategies alongside load balancing, such as limiting excessive connections from a single source and setting up rate-limiting rules.

• Leverage Geo-based Load Balancing

For global businesses, using geo-based load balancing can significantly improve the user experience. This strategy directs users to the server closest to their geographic location, reducing latency and speeding up content delivery. By leveraging GeoDNS, businesses can ensure that customers experience fast, reliable service no matter where they are located.

• Monitor and Optimize Regularly

After setting up load balancing, ongoing monitoring and optimization are crucial to maintaining performance. Regularly assess traffic patterns, response times, and server health to ensure the configuration continues to meet your needs. Make adjustments as your infrastructure or traffic load changes to keep everything running smoothly.

Conclusion

As always you should know the needs of your organization to choose how exactly to implement the load balancing. Based on the advantages we recommend to start with a Cloud-based Load Balancing. You can sign up for free to use Round Robin DNS or if you want to use the more advanced GeoDNS service, you can find details about prices and features on our website.

The post What is Load Balancing? appeared first on ClouDNS Blog.

Why do we need load balancing?

With the massive increase of the internet traffic each year, it is getting harder to provide a sustainable service for all the millions of clients without having some downtime. For this purpose, you need to apply a model of load balancing, that will reduce the load caused by the countless users trying to reach your website or use your application.

Another reason why you need to use load balancing is the rising number of DDoS attacks. To evade them you will need to spread the traffic to as many as possible servers that you have. That way, their combined efforts can resist the wave of high traffic.

DNS load balancing explained

DNS load balancing is a technique that distributes incoming web traffic across several DNS servers by associating a single domain name with multiple IP addresses (IPv4 and IPv6). When users request the domain, DNS servers provide different IP addresses in a DNS Round-Robin fashion or based on other algorithms that help effectively spread the load. That way, traffic is distributed across multiple servers, preventing any single server from becoming overwhelmed and maintaining overall service availability.

Pros of DNS load balancing

Some of the main benefits of DNS load balancing include the following:

• Easy to Implement: It doesn’t require specialized hardware and can be implemented by only configuring DNS records. That makes it an excellent choice for businesses of all sizes.
• Geographic Distribution: It can also be utilized to direct users to servers in different geographic locations. As a result, it improves performance by reducing latency for users located at different points all over the world.
• Scalability: Adding or removing servers from the load balancing pool is a relatively easy and simple process. That makes it suitable for applications that experience changing levels of traffic.

Cons of DNS load balancing

Here are several things you should consider before implementing this technique:

• TTL Impact: DNS records have a Time-to-Live (TTL) value, which determines how long a DNS response is cached. Changing load balancing configurations might take time to propagate due to the caching mechanism.
• Limited Monitoring: It lacks real-time awareness of server health. If a server becomes unavailable, DNS will still route traffic to it until the DNS cache expires. To avoid that, you can implement a Monitoring service to help identify potential issues quickly.

Hardware load balancer (HLB)

HLBs are the first to appear sometime in the late 90s. They are hardware, which means you need to purchase the device and connect it to your network. Hardware load balancing (HLB) distributes traffic across multiple servers depending on the servers’ process power, the connections, usage of resources or randomly.

The hardware load balancers are implemented on Layer4 (Transport layer) and Layer7 (Application layer). On Layer4 it makes use of TCP, UDP and SCTP transport layer protocol details to make decision on which server the data is to be sent.

Suggested article: Comprehensive Guide on TCP Monitoring vs. UDP Monitoring

On Layer7, the hardware forms an ADN (Application delivery network) and passes on requests to the servers as per the type of the content.

Pros of Hardware load balancing

Here are the primary benefits of Hardware load balancing:

• Advanced Features: Hardware load balancers can perform complex traffic distribution algorithms, considering factors like server health, response times, and content-based routing, leading to more efficient traffic distribution.
• Real-Time Monitoring: These devices continuously monitor server health and network conditions, enabling immediate traffic redirection in case of server failures or high loads.
• Enhanced Scalability: Hardware load balancers can handle large amounts of traffic and provide seamless scalability for growing services.

Cons of Hardware load balancing

Some of the drawbacks or things you should have in mind when choosing this method for load balancing are the following:

• Cost and Complexity: Implementing hardware load balancing requires a significant investment in specialized hardware devices and ongoing maintenance, which might be a barrier for small to medium-sized businesses. Configuration and management can be complex, especially for organizations without specialized networking experts.
• Single Point of Failure: While hardware load balancers enhance server availability, they themselves can become single points of failure. Proper advanced configuration is often necessary to mitigate this risk.

DNS load balancing vs. Hardware load balancing

We will compare them in two conditions, with a single data center, and with cross data center load balancing.

In the first scenario, both are very competitive. The main difference is in price. The DNS load balancer can be more accessible because usually it is offered as a subscription. In the case of HLB you must buy it and if you need extra power in the future, the upgrades can come very costly. The DNS service can be scaled easier, just by updating to another plan.

In the second scenario with cross data center, things are similar. It is getting very expensive to create a global server load balancing with the HLB because you need to properly equip every of your data center.

With global in mind, the DNS load balancing has a clear advantage over the HLB with scalability and price. The DNS option has a better failover and easy recovery.
Another advantage of the DNS load balancing is the cost to maintain. The DNS services are mostly offered as Managed DNS, so it requires less maintenance.

Which One to Choose?

Choosing between DNS load balancing and hardware load balancing largely depends on the specific needs and resources of your business.

DNS load balancing is generally more cost-effective and easier to implement, making it ideal for small to medium-sized businesses or those with inconsistent traffic levels. Its scalability and ability to direct traffic based on geographic location provide a significant advantage for globally distributed user bases. However, it’s important to consider the limitations, such as the impact of TTL on configuration changes and the lack of real-time server health monitoring, which can actually be compensated by implementing ClouDNS’s monitoring service. Despite these drawbacks, DNS load balancing offers a flexible and affordable solution for many online services.

On the other hand, hardware load balancing is better suited for enterprises requiring advanced features and robust real-time monitoring capabilities. The hardware solution offers more sophisticated traffic distribution algorithms, taking into account server health and network conditions to optimize performance. Although the initial investment and complexity in setup and maintenance are higher, hardware load balancers provide enhanced scalability and reliability for handling large volumes of traffic. They are particularly beneficial for applications requiring high availability and minimal latency.

Finally, your decision should consider the cost, desired level of control, and specific performance requirements to ensure a seamless and efficient online experience for your users.

Conclusion

Both DNS load balancing and hardware load balancing offer a good solution for distributing traffic. Which one to choose depends on the needs of your company. How tight control you would like to have? How much can you invest? Do you like a subscription model with small monthly fees or do you prefer to put a lot of money every few years to have top of the notch performance?

We recommend you to try a DNS cloud-based load balancing, like our GeoDNS.
It is cost-effective, easily scalable; you can use multiple geolocation target options and have protection from DDoS attacks.

Later you can combine it with your own hardware load balancing and create a hybrid for your specific needs.

The post DNS load balancing vs. Hardware load balancing appeared first on ClouDNS Blog.

Explanation of Traffic Director 

Traffic director is a way to optimize and manage the traffic going to your domain by using geographical-based routing. Like this, your clients from Asia will get connected to your Asian servers; your European clients will connect to the closest servers they have in Europe and so on.
Traffic Director is a cloud-based implementation of Load Balancing (you can check our article on Load Balancing). It helps to improve the performance of your network. It can be incredibly useful for medium and large companies that need to deliver content to different parts of the world.

Some companies call this service traffic director, others Global Traffic Director (GTD) or GeoDNS director, but it is best known as GeoDNS, and that is why we use this term as the name of our service.

How does it perform?

Traffic Director gives you easy access to a powerful global load-balancing system by making configuration easy. All you need to do is set your own regional rules, and the Traffic Director will intelligently direct DNS queries through strategically-placed nameservers.

ClouDNS enables you to optimize your query traffic with custom regionalization, allowing you to divide traffic across six global regions:

• Africa
• Asia
• Europe
• North America
• Oceania
• South America

By leveraging Traffic Director, you can ensure your site visitors have a better experience. For example, through regionalized configurations, queries are redirected to the geographically closest nameservers, meaning Chicago visitors would be answered by a nameserver in the North American region rather than relying on a Asia or even overseas-based server.

In addition, If you want to ensure users from France, for example, receive the best possible experience, the Traffic Director can help you achieve this. Its regionalized configurations enable you to specify that all DNS queries from the country-based region (France) should be answered by a server located in Paris. This means you can ensure users are connected to the closest, most efficient nameserver. 

DNS lookups are the first step in making any DNS request. In order to produce the best user experience, DNS traffic must be routed efficiently and with purpose. If it is not handled optimally, it can lead to poor performance and contribute to a degraded user experience. By using a Traffic Director, you can ensure users get the speedy, reliable performance they deserve.

Typical DNS vs. Anycast vs. GeoDNS

Typically, you will have few DNS servers. A visitor trying to connect will ask at random one of them for your web server’s IP address. The visitor will be lucky if the server is close and not so happy if it is far away, but he or she will get the same IP address.
If you are using just an Anycast, multiple servers will respond to the same IP. With it, the visitor will get a response from the topologically closest nameserver. The reaction is quick, but it still can take time to connect to the web server if it is far away.
Here comes the GeoDNS/Traffic Director and its advantages. By using it, a visitor will get a different IP address, depending on his/her location. It will result in fast DNS query response and consequently fast connection to the web server.

Why should you get a Traffic Director/GeoDNS?

Multiple Geolocation target options

You can efficiently target regions, countries or whole continents. You can create an exact Geolocation load balancing. Filter your visitors and direct them to the servers which are closest.

Well-placed servers
We have located our servers close to high traffic international locations.

ClouDNS network is continuously growing. We have currently 50+ Anycast DNS locations on six continents for faster DNS query resolving.

DDoS Protected DNS
DDoS attacks are becoming a common threat. For your convenience and safety, our GeoDNS plans include DDoS Protection.
DDoS attacks and how to protect ourselves

Cost Effective
Although our plans include a limited amount of queries per month, we won’t charge you extra or temporarily stop your DNS if you get additional traffic in a month or two. If this trend continues for a more extended period, we will just propose a more suitable plan for your needs.

EDNS-client/subnet support
Our service makes decisions based on the real locations of the visitors, not on those of the DNS resolver.

SEO friendly
One of the most important factors of SEO is the speed. Thanks to the Network System of servers, the DNS queries will be resolved faster, and this will help you have higher SEO ranking.

Who can benefit from using Traffic Director?

Traffic Director, with its advanced load balancing and network traffic management capabilities, can provide significant advantages for a wide range of industries and sectors. Here are some key entities and scenarios where a Traffic Director can be highly beneficial:

• Large Enterprises and Corporations: Companies with large online operations, such as those in e-commerce, financial services, and digital media, can highly benefit from Traffic Director. It ensures that their websites and applications can handle massive traffic volumes efficiently, improving user experience and minimizing downtime during peak periods.
• Cloud Service Providers: Providers that offer cloud computing resources and infrastructure as a service (IaaS) can use Traffic Director to manage and distribute traffic across their data centers more effectively. That way, it enhances performance and reliability and optimizes resource utilization, leading to cost efficiency.
• Telecommunications Companies: Telecom operators can use a Traffic Director to manage the vast amounts of data passing through their networks. By efficiently routing traffic, they can enhance the quality of service for their subscribers and reduce the load on network infrastructure.
• Online Gaming and Entertainment: In industries where customer satisfaction is closely tied to the responsiveness and stability of the service, like online gaming, Traffic Director is a game-changer. It plays a crucial role in managing sudden spikes in traffic and maintaining a seamless user experience.
• Global Businesses: For businesses operating across multiple geographical locations, the Traffic Director helps implement global load balancing. That way, it ensures that users worldwide receive quick and reliable access to their services.

Conclusion

GeoDNS or Traffic Director as some call it can significantly improve your DNS network. Your visitors will be happy, connecting faster to your website and you can even deliver them different content depending on their location. GeoDNS is an excellent solution for media companies who need to provide high-quality content to different users from all around the world as fast as possible.

The post What is Traffic Director? appeared first on ClouDNS Blog.

How does a CDN work?

To shorten the physical distance between the users and the hosting server, the CDN keeps cached versions of the original content in different geographical locations known as Points of Presence (PoP). Each of these PoPs is located strategically to serve to the users nearby.
This way, you as a user, don’t need to connect to the original source (the original server). The CDN will direct you to the closest connected server on the network, and you will get the cached version of the original version.

The benefits of a CDN

• The most obvious is the speed. The content loads faster. According to recent tests from the Content Delivery Network KeyCDN, using a CDN reduces website latency on average by 73% compared to websites running without a CDN.
• Handle heavy traffic. The load is handled between the PoPs and it is not so heavy for the original server.
• It reduces the bandwidth consumption.
• It is more secure and protects you from DDoS attacks, more Points of Presence (PoPs), fewer chances of your original server to be affected.
• Faster loading time will improve the SEO of the website.
• There are more benefits but these are the main. Based on these advantages, the CDNs are getting more and more popular every day. Especially for E-commerce and Entertainment.

Do I need a CDN for my website?

The internet has become quite dependent on Content Delivery Network to manage a significant amount of its content. But just because CDNs are a common practice doesn’t mean you need to consider investing in one. It’s necessary to understand how CDN DNS works and consider whether it’d be useful for your website’s needs.

CDNs are great for allowing users to access web content quickly and efficiently, even if they’re far away from where your web origin host is located. If most of your audience is nearby and can effectively access your website without much difficulty, then you may not need a CDN for your website. However, if you’re reaching a larger audience from different places, then it would be wise to invest in a CDN service. Video streaming websites, social media platforms, online journalism outlets, digital publications and eCommerce sites all benefit from having their own CDN, because it makes it easier for them to reach a larger global audience. It also allows for faster loading, which can provide more potential visitors and more potential readers. 

Overall, the advantages of a fast-loading website far outweigh the costs, and should not be ignored.

Does DNS need to be modified to support CDN?

Yes, DNS must be modified to support CDN. Domain Name System (DNS) stores, logs and allocates the IP address of your web content between web users and your web server, so any change in web content needs to be reflected in the underlying DNS record. CDN, on the other hand, adds multiple distributed server networks to reduce the amount of time needed for content to travel from the origin to the final destination. In order for these different distributed networks to work effectively, the DNS must be configured to route requests through the CDN, which allows for quicker content delivery and reduced latency. Furthermore, CDNs also use DNS to direct visitors geographically to their nearest server, which helps reduce the time it takes for the web content to load on their browser.

How to create your own CDN using DNS

To set up a CDN using your own Anycast can be very expensive. But don’t worry, there are cheaper solutions. For example, you can use GeoDNS and ordinary servers with unique IP addresses. With our GeoDNS service you can build your own CDN or Geolocation Load Balancing with highly accurate geolocation service that makes the decisions based on the real location of the visitor, not on the location of the DNS resolver. You can easily configure your DNS zone to show American server IP to the visitors from The USA and to the European visitors, another IP from Europe.
It might sound hard to you but don’t worry, we can help you. Our professional team of experts can provide you directions and you can start benefiting from your CDN in no time. Give it in our hands and we will do all the configuration needed.

So what are you waiting for? Make the experience for your visitors better and faster. Segment your traffic and send users to the servers designed just for them. This can increase their happiness and make them more likely to engage and convert.

The post How to create your own CDN using DNS appeared first on ClouDNS Blog.