dns load balancing Archives - ClouDNS Blog https://www.cloudns.net/blog/tag/dns-load-balancing/ Articles about DNS Hosting and Cloud Technologies Wed, 23 Oct 2024 07:54:52 +0000 en-US hourly 1 https://wordpress.org/?v=6.2.6 What is a DNS outage (DNS downtime), and how to avoid it? https://www.cloudns.net/blog/what-is-a-dns-outage-dns-downtime-and-how-to-avoid-it/ https://www.cloudns.net/blog/what-is-a-dns-outage-dns-downtime-and-how-to-avoid-it/#respond Tue, 22 Oct 2024 07:37:00 +0000 https://www.cloudns.net/blog/?p=2061 Knowing what DNS is can already show you the answer to what DNS outage is. The clients won’t resolve your domain name, so they will get an error and won’t be able to reach your site or use your application. The DNS downtime could lead to angry customers, lost sales, and bad branding. But you …

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Knowing what DNS is can already show you the answer to what DNS outage is. The clients won’t resolve your domain name, so they will get an error and won’t be able to reach your site or use your application. The DNS downtime could lead to angry customers, lost sales, and bad branding. But you can avoid DNS outages. Do you want to know how? 

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. 

DNS outage

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!

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What is Load Balancing? https://www.cloudns.net/blog/load-balancing/ https://www.cloudns.net/blog/load-balancing/#comments Thu, 10 Oct 2024 10:24:47 +0000 https://www.cloudns.net/blog/?p=74 Only an incredible technique like Load balancing can help you improve your performance, optimize your website, provide redundancy, and enhance your protection. That is right! You can get all of these benefits with this simple yet powerful technique. Let’s dive deep and explain more about it! Load Balancing – Definition The network performance has become …

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Only an incredible technique like Load balancing can help you improve your performance, optimize your website, provide redundancy, and enhance your protection. That is right! You can get all of these benefits with this simple yet powerful technique. Let’s dive deep and explain more about it!

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. 

Load balancing

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.

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DNS load balancing vs. Hardware load balancing https://www.cloudns.net/blog/dns-load-balancing-vs-hardware-load-balancing/ https://www.cloudns.net/blog/dns-load-balancing-vs-hardware-load-balancing/#respond Thu, 01 Aug 2024 10:18:31 +0000 https://www.cloudns.net/blog/?p=571 DNS load balancing and hardware load balancing are two different methods for distributing traffic effectively among servers. They help in enhancing reliability and guaranteeing simple and quick access to online services. Yet, which one is the best for you and your online business? Keep reading to understand these techniques better, explore their benefits and help …

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DNS load balancing and hardware load balancing are two different methods for distributing traffic effectively among servers. They help in enhancing reliability and guaranteeing simple and quick access to online services. Yet, which one is the best for you and your online business? Keep reading to understand these techniques better, explore their benefits and help you choose the right path for seamless online experiences. So, let’s start!

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.

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