How to scale out horizontally?

When demand for your application or website is increasing and you need to expand its accessibility, storage power, and availability levels, is it better to scale horizontally r vertically. Capacity planning is a challenge that every engineering team faces when it comes to ensuring the right resources are in place to handle expected (and unexpected) traffic demands.

Here we are going to see about horizontal scaling options.Using Load balancer:

Load balancing is a core networking solution used to distribute traffic across multiple servers in a server farm. Each load balancer sits between client devices and backend servers, receiving and then distributing incoming requests to any available server capable of fulfilling them.
In AWS cloud we have auto scaling option to add EC2 instances depending on the traffic.

DNS-based Load Balancing is the practice of configuring a domain in the Domain Name System (DNS) such that client requests to the domain are distributed across a group of servers. … Dynamic DNS load balancing: DNS requests are routed between domain servers with the best available resources and minimal load with the round-robin fashion.Using this approach their is disadvantage w.r.to TTL attached to DNS entries. even if we set low TTL also.

Connected and stateful application it will store the session details with the help of stickiness in the loadbalancer. Sticky sessions is determining how long your load balancer should consistently route the user’s request to the same target server.

Disconnected architecture models suits when we need enough time to get the results for the processed data. We can add no. of servers to the queue it will process the data and get the results. This models suits for e-commerce websites.

And another method is distributed data processing method of organizing data processing that uses a central computer in combination with smaller local computers or terminals, which communicate with the central computer and perhaps with one another. Mostly this method used for offline jobs.