Difference between auto scaling and load balancing
Although both load balancing and autoscaling are automated procedures that aid in the development of scalable and economical systems, their primary goals and modes of operation are different:
Concentrate
Whereas auto scaling concentrates on resource management, load balancing concentrates on traffic management.
How they operate
While auto scaling adjusts the number of servers in response to demand, load balancing divides traffic among several servers.
How they collaborate
Auto scaling can start new instances for load balancing to attach connections to, while load balancing can assist auto scaling by redirecting connections from sick instances.
Additional information regarding load balancing and auto scaling is provided below:
Balancing loads
Distributes requests among several servers using algorithms. Each instance’s health can be checked by load balancers, which can also route requests to other instances and halt traffic to unhealthy ones.
Auto-scaling
Determines when to add or delete servers based on metrics. Application requirements for scaling in and out instances can serve as the basis for auto scaling strategies.
Advantages
Auto scaling can optimize expenses and automatically maintain application performance.
Application autoscaling is strongly related to elastic load balancing. Load balancing and application autoscaling both lessen backend duties, including monitoring server health, controlling traffic load between servers, and adding or removing servers as needed. Load balancers with autoscaling capabilities are frequently used in systems. However, auto-scaling and elastic load balancing are two different ideas.
Here’s how an application load balancer auto scaling package complements it. You can reduce application latency and increase availability and performance by implementing an auto scaling group load balancer. Because you may specify your autoscaling policies according to the needs of your application to scale-in and scale-out instances, you can control how the load balancer divides the traffic load among the instances that are already running.
A policy that controls the number of instances available during peak and off-peak hours can be established by the user using autoscaling and predetermined criteria. Multiple instances with the same capability are made possible by this; parallel capabilities can grow or shrink in response to demand.
An elastic load balancer, on the other hand, just connects each request to the proper target groups, traffic distribution, and instance health checks. An elastic load balancer redirects data requests to other instances and terminates traffic to sick instances. It also keeps requests from piling up on any one instance.
In order to route all requests to all instances equally, autoscaling using elastic load balancing involves connecting a load balancer and an autoscaling group. Another distinction between load balancing and autoscaling in terms of how they function independently is that the user is no longer required to keep track of how many endpoints the instances generate.
The Difference Between Scheduled and Predictive Autoscaling
Autoscaling is a reactive decision-making process by default. As traffic measurements change in real time, it adapts by scaling traffic. Nevertheless, under other circumstances, particularly when things change rapidly, a reactive strategy could be less successful.
By anticipating known changes in traffic loads and executing policy responses to those changes at predetermined intervals, scheduled autoscaling is a type of hybrid method to scaling policy that nonetheless operates in real-time. When traffic is known to drop or grow at specific times of the day, but the shifts are usually abrupt, scheduled scaling performs well. Scheduled scaling, as opposed to static scaling solutions, keeps autoscaling groups “on notice” so they can jump in and provide more capacity when needed.
Predictive autoscaling uses predictive analytics, such as usage trends and historical data, to autoscale according to future consumption projections. Particular applications for predictive autoscaling include:
- Identifying significant, impending demand spikes and preparing capacity a little beforehand
- Managing extensive, localized outages
- Allowing for greater flexibility in scaling in or out to adapt to changing traffic patterns over the day
Auto scaling Vertical vs Horizontal
The term “horizontal auto scaling” describes the process of expanding the auto scaling group by adding additional servers or computers. Scaling by adding more power instead of more units for instance, more RAM is known as vertical auto scaling.
There are a number of things to think about when comparing vertical and horizontal auto scaling.
Vertical auto scaling has inherent architectural issues because it requires increasing the power of an existing machine. The application’s health is dependent on the machine’s single location, and there isn’t a backup server. Downtime for upgrades and reconfigurations is another need of vertical scaling. Lastly, while vertical auto scaling improves performance, availability is not improved.
Due to the likelihood of resource consumption and growth at varying rates, decoupling application tiers may help alleviate some of the vertical scaling difficulty. Better user experience requests and adding more instances to tiers are best handled by stateless servers. This also enables more effective scaling of incoming requests across instances through the use of elastic load balancing.
Requests from thousands of users are too much for vertical scaling to manage. In these situations, the resource pool is expanded using horizontal auto scaling. Effective horizontal auto scaling includes distributed file systems, load balancing, and clustering.
Stateless servers are crucial for applications that usually have a large user base. It is preferable for user sessions to be able to move fluidly between several servers while retaining a single session, rather than being restricted to a single server. Better user experience is made possible by this type of browser-side session storage, which is one outcome of effective horizontal scalability.
Applications that use a service-oriented architecture should include self-contained logical units that communicate with one another. This allows you to scale out blocks individually according to need. To lower the costs of both vertical and horizontal scalability, microservice design layers should be distinct for applications, caching, databases, and the web.
Due to the independent creation of new instances, horizontal auto scaling does not require downtime. Because of this independence, it also improves availability and performance.
Don’t forget that not every workload or organization can benefit from vertical scaling solutions. Horizontal scaling is demanded by many users, and depending on user requirements, a single instance will perform differently on the same total resource than many smaller instances.
Horizontal auto scaling may boost resilience by creating numerous instances for emergencies and unforeseen events. Because of this, cloud-based organizations frequently choose this strategy.
