Load Balancing Methods
Definition - What does Load Balancing Methods mean?
Load balancing methods are algorithms or mechanisms used to efficiently distribute an incoming server request or traffic among servers from the server pool. Efficient load balancing is necessary to ensure the high availability of Web services and the delivery of such services in a fast and reliable manner. To meet a high traffic demand, servers are replicated. An incoming load or request to a server is shared across such replicated servers, and this process is known as load balancing. To effectively schedule the routing of requests from a client to the respective servers in an optimized way, several load balancing methods are used such as round robin, least connections, adaptive balancing, etc.
Techopedia explains Load Balancing Methods
Load balancing methods are also known as algorithms for load balancing or scheduling methods as they specify the manner in which a server load is shared across a server pool. There are various load balancing methods available, and each method uses a particular criterion to schedule an incoming traffic. Some of the common load balancing methods are as follows:
- Round robin -- In this method, an incoming request is routed to each available server in a sequential manner.
- Weighted round robin -- Here, a static weight is preassigned to each server and is used with the round robin method to route an incoming request.
- Least connection -- This method reduces the overload of a server by assigning an incoming request to a server with the lowest number of connections currently maintained.
- Weighted least connection -- In this method, a weight is added to a server depending on its capacity. This weight is used with the least connection method to determine the load allocated to each server.
- Least connection slow start time -- Here, a ramp-up time is specified for a server using least connection scheduling to ensure that the server is not overloaded on startup.
- Agent-based adaptive balancing -- This is an adaptive method that regularly checks a server irrespective of its weight to schedule the traffic in real time.
- Fixed weighted -- In this method, the weight of each server is preassigned and most of the requests are routed to the server with the highest priority. If the server with the highest priority fails, the server that has the second highest priority takes over the services.
- Weighted response -- Here, the response time from each server is used to calculate its weight.
- Source IP hash -- In this method, an IP hash is used to find the server that must attend to a request.
Each method has its own set of benefits and suitable scenarios. The optimal algorithm that best suits the purpose can be selected by the service provider to give a smooth, reliable and fast service delivery to its clients.