Load balancing vs failover – Load balancing is a technique of distributing your requests over a network when your server is facing heavy traffic load and putting load on the CPU or disk or database IO rate. The objective of load balancing is optimising resource use and minimising response time, thereby avoiding overburden of any one of the resources.
The goal of failover is the ability to continue the work of a particular network component or the whole server, by another, whenever the first one fail. Failover allows you to perform maintenance of individual servers or nodes, without any interruption of your services.
It is important to note that load balancing and failover systems may not be the same, but they go hand in hand in helping you achieve high availability of the server.
Carrying out Load Balancing:
Albeit load adjusting is exceptionally clear, its execution isn’t. In this post, I would address the essential thoughts of execution of load adjusting. Load offsetting can be performed with the assistance of equipment and programming and at times a blend of both.
The easiest method of burden adjusting is to utilise various servers for various administrations.
For example, you could run the web server on one occurrence, the information base server on another and serve static substance through a CDN. It’s simple in light of the fact that there is no issue of information replication.
A subsequent method for performing load adjusting is to have different front end servers. That would imply that different IP tends to would be arrangement for a similar area. At the point when a customer sends a solicitation, an arbitrary IP address is given to him, spreading the heap around.
One more method of carrying out load adjusting is by utilising a solitary Virtual IP, which is given to all customers. The server at the Virtual IP then re-courses the solicitations to the genuine servers. Normally, HAProxy is utilised to play out this errand of burden adjusting, sitting before all servers. HAProxy distinguishes which server is up or down and sends demands as indicated by that.
Carrying out Failover:
Since failover includes the frameworks going down (or coming up short) totally, the information should be available at all servers, or at the end of the day, there is a requirement for information replication. In Unix based frameworks, document frameworks can be synchronised utilising rsync and cron occupations, while for information bases, you really want to set up replication frameworks like MySQL replication.
Failover normally includes two servers-an essential and an auxiliary server. The essential takes the typical burden, handling demands, while the auxiliary screens the essential and hangs tight for it to close down to assume control over the administrations.
For the cycle to happen effectively, you want to identify the disappointment in a framework and consequently, course the solicitation to another framework. This failover can be set off by changing the IP address that your space focuses to. Notwithstanding, IP address changes require a couple of moments to be carried out.
We trust that this post assisted you with understanding the nuts and bolts of burden balancers and failover frameworks and filled in as a significant stage for you in executing these methods to your item.
Some important study notes