In a recent post I talked about how you need APIs as your business grows; how services need to integrate directly to a companies' business processes through APIs rather than indirectly through a portal or Web site. Check it out here.
This time, because APIs need to scale, I talk about how you need the Cloud to effectively manage those APIs and enable developers to be successful using your APIs to build their apps.
You need a cloud to effectively manage your APIs.
Let's start by comparing API usage in the traditional enterprise scenario with API usage in the growing API economy around social and mobile applications.
In a traditional enterprise model it takes years to build out the enterprise ecosystem of apps and the life span of an app is often measured in decades. Traditional enterprise apps connected to back-end systems are typically designed to carefully shrink and grow their IT capacity. Change is slow, IT requirements are predictable but capacity needs to be available to support maximum loads.
In the new API economy - in a world of mobile and social apps development - we're working in an environment of rapid innovation and a usage model in which we cannot predict or preconfigure capacity. IT needs are not as predictable as in the traditional model. Burstiness or spikes in requests happen as a result of a number of things: API access and usage changes from within apps, app users come and go, apps can get popular for a few weeks, create a surge in demand, then subside. It's a rapidly changing environment in which you need to be able to scale and respond to rapid bursts of requests that create periods of peak system usage.
Hosting your APIs in the cloud offers the ability to provision and deprovision as needed. In other words, you can avoid spending at the peak rate - rather spend at an average rate and take advantage of cloud elasticity and burst as required in times of peak load. Several enterprise API customers already leverage the Cloud for variable capacity.
Should the cloud be internal or external to your business? Inside or outside your firewall?
Unless your app developers and the APIs they leverage are entirely within the walls of your enterprise, I recommend that your APIs are hosted in a cloud outside your firewall. There are a few reasons:
- The developers who will use your APIs - your audience - are external to your enterprise and supporting these developers is priority.
- Those developers are familiar with using public APIs. Developers are busy building social and mobile apps meaning that they're comfortable in an environment in which they connect to public APIs offered by Facebook, Twitter, Twilio, SimpleGeo, and so on.
- It is common for developers to use more than one provider's API in building their apps. If APIs are behind your firewall, you make it more difficult for developers to access those APIs as they need to navigate different firewalls and different back-end systems for the different APIs they want to use. This will adversely impact developer adoption of your APIs.
In summary, you need a Cloud to be able to scale and respond to the dynamic nature of today's API-driven apps. The Cloud should be on the Web outside your enterprise firewall to effectively support your customers - app developers.