Performance and scalability are two of the key aspects of software design.
It used to be an acknowledged fact that developers had to sacrifice performance to build highly scalable software, but that isn’t true for modern applications.
Now advanced technologies are available to preserve performance as software scales.
Building for Performance
“Performance” refers to the speed and effectiveness of a system under a given workload within a given time frame.
In layman’s terms, it measures how well software can perform its intended task.
Several factors are included under the “performance” umbrella, specifically:
- Speed: how much time the system takes to transmit data
- Throughput: the number of transactions successfully executed per second
- Responsiveness: how long it takes an application to respond to a request
- Availability: the percentage of time an application is usable
Achieving an acceptable level of performance is absolutely mandatory when developing software.
If the application doesn’t work, it’s a waste of resources. Internal employees won’t use products that only add to technological complexity.
Customers may download a app if the marketing is effective, but they’ll abandon it after one use. In both cases people will be less likely to download later apps.
Scaling for Success
“Scalability” is the ability of software to handle a sudden increase in workload.
The increase could come from a surge in simultaneous users, a rising amount of data being processed, more individual requests for access, or anything else that placed higher demands on available resources.
Scaling can be achieved by “scaling up” or “scaling out”. Scaling up (or scaling vertically) means using better or higher capacity resources.
For example, running an application on a machine with a faster CPU would be vertical scaling.
Scaling up is incredibly simple; the same application can be run on the more powerful machine without changing it.
However, this solution can’t be applied infinitely since there’s only so much more advanced the hardware can get within a reasonable time frame.
It also gets more expensive as it scales into pricier equipment.
Scaling out (otherwise known as horizontal scaling) involves adding more resources to a system by adding more nodes within it.
Running an application on multiple computers as opposed to one machine is a way to scale horizontally.
Because the added machines can be of the same type, scaling out carries a lower cost. It’s easy to do without significant downtime.
Without the proper application architecture, though, scaling out can lead to a drop in performance as the nodes struggle to communicate with each other.
Finding a Balance
While performance is critical, it would be a mistake to label it the priority and regard all other traits as secondary.
Scalability affects performance as an application grows, and applications are usually meant to grow.
Planning for scalability from the start is cheaper and easier- but there’s no need to sacrifice performance when preparing for the future. Apps can be both fast and scalable.
The vast majority of global scale applications (like Google or Amazon) scale out.
They narrow the performance gap by implementing a number of modern technologies.
- Load balancing software intelligently spreads the processing load over the available nodes, providing maximum availability and throughput.
- Programming languages like Node.js enable lightweight apps that run on fewer servers.
- Cloud databases make it easy to add more storage without disrupting availability.
The trick is that these tools must be incorporated into an application’s architecture from the beginning.
The small amount of time building for scale adds to the development schedule makes a huge difference in an app’s performance at scale.
When other benefits like lower overall maintenance costs and longer application lifetimes are considered, there’s no reason scalability shouldn’t be considered in every app that will be used outside a single office.
Performance may be the most noticeable trait of applications, but scalability keeps apps running well under pressure. Considering both during development is just good business.