Load Balanced Servers

[Merrick]

It is quite difficult for me to understand the concept of Load Balancing and have the following doubts:-

• What is Load Balancing (layman language please)?
• Which operating system is needed for Load Balancing?
• What is the required specification?

Thank you
Merrick

[Catherine]

Hello Merrick,

I have answered all your questions below :

1) Load balancing is a concept which involves a number of servers so that the website load gets distributed on a number of servers and the load is not concentrated on one single server. This is usually done by websites which have a huge amount of traffic.

2) It is not necessary to have a specific operating system for load balancing. You can have Windows or Linux operating system for load balancing architecture. However, the required configuration may change due to the operating system you choose.

3) Load balancing needs more than one Dedicated server of the same configuration. However, you may also need some other addons depending on your needs.

Hope this helps...

[Ryan]

Server Cluster involves multiple servers which distribute the load among themselves in order to achieve web server scalability. The load distribution among these servers is known as load balancing. Load balancing distributes traffic efficiently among network servers so that no individual server is overburdened.

As far as Linux based load balanced servers architecture is concerned, Linux CentOS or RHEL are the recommended ones. For setting up a Windows based Load Balanced servers architecture, certain Windows operating systems like Windows 2003 Enterprise edition and Windows 2008 Web edition are required.

[MattBarthorp]

In computer networking the load balancing technique is used for spreading work between two or more computers, network links, CPU’s and other resources, in order to get optimal resource utilization. Usage of multiple components with load balancing increases the reliability through redundancy. Load balancing is used as a mediator in internal communications in computer clusters.Load balanced systems include popular websites, Internet Relay chats, high bandwidth FTP (File Transfer Protocol) sites, NNTP servers and DNS servers.

[Merrick]

Thank you all for answering my questions.

Server Cluster involves multiple servers which distribute the load among themselves in order to achieve web server scalability. The load distribution among these servers is known as load balancing. Load balancing distributes traffic efficiently among network servers so that no individual server is overburdened.

So is it possible to use Load Balancing and Server Clusters on the Same Set of Nodes?

[eUK-Martin]

So is it possible to use Load Balancing and Server Clusters on the Same Set of Nodes?

No, you can either have a Load Balanced server or Clustered server. There are numerous reasons for them to not work together however some basic are:

1. NLB require all the IP addresses to be assigned to all the nodes where as cluster would only switch the IP at the time of fail over, one cannot have then on all node at a time.
2. Cluster require AD and NLB cannot have AD since communication between 2 nodes is not permitted in NLB through dedicated IP.

[eUK-Gareth]

Network Load Balancer is used to balance TCP/IP traffic among the 2 or more servers. The servers participating in the NLB cluster doesn't share storage or other resources, but instead run their own instances of the load-balanced applications. For i, each server would run IIS with an instance of the same Web site, but each would be a separate copy. NLB simply manages the incoming traffic and balances it out to the servers participating in the cluster.

NLB Doesn't provides failover capability, but the Cluster Service does provide redundancy and failover capability. Servers in this type of cluster generally share common storage and function as a single, logical unit. By contrast, an NLB cluster is a group of individual servers working independently to process the traffic that the NLB service passes their way. Essentially, the NLB service enables all servers in the NLB cluster to be addressed by a single IP address. You can combine NLB clustering with Cluster Service clusters, but these two cluster types must remain separate; that is, a server can’t participate in both types of clusters. The usual solution is to build an NLB cluster upstream to service a Cluster Service cluster.

[Jack]

So is it possible to use Load Balancing and Server Clusters on the Same Set of Nodes?

Windows and Linux load balancing is completely a different setup. Which one you are looking at ?

[Merrick]

Windows and Linux load balancing is completely a different setup. Which one you are looking at ?

Well, I asked irrespective of OS. However, I'm looking at Linux Load Balancing. How do both differ in setup please?

[Catherine]

Linux and Windows have quite a different setup. However, the purpose would be the same. Please be advised that the cost of the Windows Load balancing Dedicated servers will be higher in comparison to Linux Load balancing Dedicated servers due the Licensing charges required for Windows Operating system.

[Ryan]

Well, I asked irrespective of OS. However, I'm looking at Linux Load Balancing. How do both differ in setup please?

A typical Linux based Load Balanced servers' architecture consists of 2 or more similar configuration web servers which are behind a Load Balancer. Each web server will have a public IP assigned to it as well as an Internal LAN IP. After the implementation of Load Balancing routing rules on the Load Balancer, we configure Firewall rules to allow web traffic on the web servers to pass through the Load Balancer. The Load Balancer will then take care of equal distribution of traffic on each of the web servers who then pass on SQL queries to the database server.

[Merrick]

Thank you Ryan!

Just got a link on EUK site which to helped me in understanding the concept of Load Balancing. The link is:-
Load Balanced Web Servers and MySQL Servers | Web Hosting UK | Dedicated Servers | VPS Hosting.

[MattBarthorp]

Thank you for the link Merrick. The pictoral description helps to understand the concept in a better way.

[Merrick]

Thank you for the link Merrick. The pictoral description helps to understand the concept in a better way.

You are most welcome

You can read this forum from the beginning and I'm sure that it will help you much to understand the concept of Load Balanced Servers. All the posts by EUK Rocks are in pretty simple language. However still if you have any issues regarding Load Balancing you can post them here. I'm sure you will get a quick response from

[alevin46]

Hello Friends.........

Load balancing helps make networks more efficient. It distributes the processing and traffic evenly across a network, making sure no single device is overwhelmed. Web servers, as in the example above, often use load balancing to evenly split the traffic load among several different servers.

Thanks