DNS Load Balancing

Intelligent traffic distribution for high availability and low latency

FAILOVER, ROUND ROBIN, PERFORMANCE LOAD BALANCING

DNS Load Balancing distributes your query traffic across multiple resources based on resource availability and performance.
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Load balancing is commonly used to manage traffic flow between redundant systems, such as web servers or CDN services. All systems in the configuration are always “live” and each handles a share of incoming traffic. That way, if one system is unavailable, the rest will take over the load with no appreciable impact on end-users.
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These kinds of multi-cloud architectures have sky-rocketed in popularity over the past few years, thanks to advances in DNS management, which have made load balancing across multiple cloud services significantly more affordable and accessible than traditional hardware load balancers.

DNS load balancing is also remarkably faster since there are no extra lookups to a third-party service. Everything happens right at the DNS level! Your DNS records act as a sort of traffic director, choosing what traffic to send to which resource.
Constellix takes load balancing one step further, by letting you inject your own custom logic into your configurations. You can apply rules that optimize traffic flow based on resource performance, cost, and network topography. Or write your own rules based on the querying client’s location or network.

ENHANCED FAILOVER
LB + Health Checking

Easily integrate health checks into your load balancing configurations, with baked-in Failover. Failover automatically moves your traffic from unavailable resources to healthy ones.
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‍The "most affordable" and "easiest to configure" kind of load balancing.
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✓ DNS Failover is natively integrated with almost all of our services:
✓ GeoProximity
✓ Global Load Balancing
✓ Traffic Steering
✓ Round Robin
✓ Latency Load Balancing
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Failover is supported for A, AAAA, ANAME, and CNAME records. All you need to do is enable Failover for your record, and specify the IP addresses or hostnames of your "backup" resources. These backups are only used when the primary IP/hostname is unavailable.

Types of DNS Failover

There are three settings for enhanced Failover. Rankings determine the order the backup IP addresses will be served when the primary IP is unavailable.

Multi-Value LB
‍Round Robin

The most basic of load balancing services is called round-robin. Round-robin is often compared to a rotor because it returns one endpoint at a time in a cyclical manner.

Let’s say you want to point your domain to three geographically distributed web servers: 1.1.1.1 , 2.2.2.2 , and 3.3.3.3 with round-robin enabled. Each time your domain is queried, it will return the next IP in the list.

Multi-Value + Weights
Weighted Round Robin

The second kind of load balancing is called weighted round-robin and allows you to distribute uneven amounts of traffic across your endpoints. This is a great way to prioritize servers and resources in your network that have more capacity. You can also use weights to slowly roll out an update to only segments of your users at a time.
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Record Pools
In Constellix, you need to configure weighted round-robin using record pools. Pools are groups of endpoints, which are applied to DNS records. When the record is queried, it will rotate through the different endpoints in the pool at each request. We like to think of round-robin pools as rotors.

There are many ways to customize record pools. For instance, you can choose how many endpoints are returned each time the record is queried.

Multi-Value + Health Checks
Round Robin with Failover

You can integrate monitoring checks with your round-robin/multi-value configurations. That way, only healthy endpoints are served to users. If an endpoint is detected as down, it will be removed from the rotation. But if it comes back as healthy, it will be included in the next cycle.

You can also use Round Robin with Failover if you want just one endpoint to be returned unless it is down. If it does come back as down, then we will Failover the other endpoints, which will be returned in a round-robin fashion.

In this case, you would create two pools, one with just your primary endpoint. The second pool would contain the endpoints you want to Failover to.

Latency Routing (ITO)
Performance-based LB

ITO, Internet Traffic Optimization, uses integrated monitoring checks, just like Round Robin with Failover, but it can also account for the round trip time (RTT) of the systems in your load balancing configuration.
Enable ITO in your load balancing pools, and traffic will only be sent to the fastest responding resource(s). You can choose to return one or multiple resources in an ITO pool.

Latency load balancing is ideal for multi-vendor configurations like multi-CDN, multi-DDoS, or multi-cloud.

Keep in mind... Latency load balancing is configured by region, so you want to have multiple resources in whichever region you are using this feature.

Regional LB
GeoDNS + Load Balancing

All of our load balancing services can be configured regionally. That means the load balancing policy will only be used when a user from a specified region makes a query for that record.

Regional load balancing can be used to build your own region-specific CDN (Content Delivery Network), create custom routing rules for a single region, and so much more.

what our customers say:
For critical web applications, you need to have an independent system that is capable of monitoring your primary infrastructure, detecting failure, and switching to an independent secondary system.
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DNS Load Balancing

FAILOVER, ROUND ROBIN, PERFORMANCE LOAD BALANCING

ENHANCED FAILOVERLB + Health Checking

Types of DNS Failover

Multi-Value LB‍Round Robin

Multi-Value + WeightsWeighted Round Robin

Multi-Value + Health ChecksRound Robin with Failover

Latency Routing (ITO)Performance-based LB

Regional LBGeoDNS + Load Balancing