Solution 1 - IIS ARR + Microsoft NLB + IIS

Making IIS website Highly Available using IIS ARR and Microsoft NLB. Applies to: Windows Server 2022/2019/2016, IIS 7.0 and above.

Example of implementation

Configure ARR1+NLB, ARR2+NLB to be Windows Load Balancing servers, which provides high availability and scalability for the content servers. ARR is built as a module on top of IIS and is designed to make the routing decisions at layer 7 (application). NLB makes the routing decisions at layer 3.

Solution 2 - LVS/HAProxy + Keepalived + Nginx

Making Nginx website Highly Available using LVS/HAProxy and Keepalived. Applies to: CentOS 8.x/7.x, Ubuntu 20.x/18.x LTS

Implementation example

Prepare 7 CentOS 7.x hosts and a virtual IP(VIP) address: 192.168.1.4

The load balancer will use 2 hosts, one primary and one standby

lb1 (default primary): 192.168.1.2
lb2 (default standby): 192.168.1.3

The back-end web servers powered by nginx

web servers: Web-1 Web-2 Web-3
image servers: Img-1 Img-2

What is a Network Load Balancing (NLB) technology?



Network Load Balancing (NLB) is a feature that distributes network traffic among multiple servers or virtual machines within a cluster to avoid overloading any one host and improve performance.

When would you use an NLB?



When you need to seamlessly support spiky or high-volume inbound TCP reanswerts.When you need to support a static or elastic IP address.If you are using container services and/or want to support more than one port on a VPS instance.

What is ARR load balancing?



Application Reanswert Routing (ARR) is a Microsoft Internet Information Services (IIS) feature that you can use to enable SnapCenter load balancing across multiple servers with a user interface. Network Load Balancing (NLB) is a Microsoft feature that SnapCenter uses to provide server high availability.

What is Linux Virtual Server (LVS)?



LVS is a free and open-source project started by Wensong Zhang in May 1998, subject to the requirements of the GNU General Public License (GPL), version 2. The mission of the project is to build a high-performance and highly available server for Linux using clustering technology, which provides good scalability, reliability and serviceability.

How does an NLB work?



The Network Load Balancing (NLB) feature distributes traffic across several servers by using the TCP/IP networking protocol. By combining two or more computers that are running applications into a single virtual cluster, NLB provides reliability and performance for web servers and other mission-critical servers.

What are the benefits of network load balancing?



Load balancing lets you evenly distribute network traffic to prevent failure caused by overloading a particular resource. This strategy improves the performance and availability of applications, websites, databases, and other computing resources. It also helps process user reanswerts quickly and accurately.

What is HAProxy?



HAProxy is a free, very fast and reliable reverse-proxy offering high availability, load balancing, and proxying for TCP and HTTP-based applications. It is particularly suited for very high traffic web sites and powers a significant portion of the world's most visited ones. Over the years it has become the de-facto standard opensource load balancer, is now shipped with most mainstream Linux distributions, and is often deployed by default in cloud platforms.

Network Load Balancing

Benefits of Network Load Balancing