Server load is a dynamic quantity, and it is almost impossible to predict the performance accurately. Load balancing is necessary for distributing workloads evenly among servers or other computing resources to optimize network efficiency, reliability, and bandwidth. A physical or virtual appliance that determines which server in the pool can best meet the request performs load balancing. If one of the servers fails, the load balancer will redirect the workload to a backup server.
Load balancing applies to layers 4-7 in the 7-layer OSI model.
- L4. Directing traffic based on network data and transport layer protocols such as IP address and TCP port.
- L7. Adds content switching to load balancing, allowing routing decisions to be made based on characteristics such as HTTP header, unified resource identifier, SSL session identifier, and HTML form data.
- GSLB. Global Server Load Balancing extends L4 and L7 capabilities to servers at different sites.
How does load balancing work?
Load balancers sit between the servers that process requests and the Internet. The load balancer receives the request, routes it to the server in the pool that is available and running. When the load is high, the load balancer dynamically adds servers; if the request is low, the load balancer dynamically removes servers.
Load balancing solutions are divided into several types:
Software load balancers – run on standard hardware (desktops, PCs) and standard operating systems.
Hardware load balancers – these are specialized units that include integrated circuits (ASICs) tailored for a specific use. ASICs provide high-speed forwarding of network traffic and are often used for load balancing at the transport layer because hardware load balancing is faster compared to a software solution.
Virtual load balancers – virtualized application delivery controller software that distributes a load of network traffic to internal servers. They are used in the case of constant traffic spikes and demands for high bandwidth.
A Cloud load balancer is a type of load balancer performed in the cloud. It is the process of distributing workloads among multiple computing resources. Load balancing in the cloud reduces the costs associated with document management systems and increases the availability of resources.
Why load balancing is important to cloud computing
Load balancers are especially useful in cloud environments where high service availability and response times are critical for certain business processes.
Load balancing also plays a key role in cloud scalability, which involves running multiple virtual servers and running multiple instances of applications. The purpose of a load balancer is to distribute traffic between these new instances.
With the balancer's ability to detect unavailable servers and redirect traffic, the cloud infrastructure can cover multiple geographic regions.
Cloud4U uses VMware NSX Edge Load Balancer. It is a solution that provides routing, Firewall, NAT, DHCP, Site to Site VPN, SSL VPN-Plus, Load Balancing, High Availability, Syslog functions for a virtual data center. It is implemented as a virtual machine connected to the virtual data center networks and external networks (Internet).
Load Balancer is available to all Cloud4U users free of charge in the EdgeGateway Compact tariff.