Think, for example, about gene sequencing: JIT compile the app once, chew on data for hours. No one cares too much about the startup time because the app will be running far long enough to amortize the cost of a thoroughly optimizing compilation.
The classic server app of today is often a web app that doesn't do a ton of work relative to its startup time. Web apps often start up, do a bit of work, then shut down. Waiting a long time for the JIT compiler degrades each launch significantly.
As others point out, there are solutions to making web apps faster. But rest assured: RyuJIT helps all kinds of apps: server, client, web, computational.
--Andrew Pardoe [MSFT]
Reading the article, it sounded to me like Microsoft's primary motivation was cutting back on their development costs by shrinking the codebase. Faster compilation was just a nice side effect that also happened to make for a sexier selling point.
But I think there is confusion—or at least I am confused—about what precisely RyuJIT provides. I know it provides quicker compilation times, which would affect the start-up time for web-apps. But does it also provider quicker-executing code? That is, does it do a better job with its optimization of web-apps' code once compiled?
Yes, a quick-starting web-app is awesome for when you need to add or replace nodes to your cluster. But I can usually suffer some warm-up time, even in that scenario.
My opinion is that web-apps are disturbingly often CPU bound and what I want most of all is faster web applications. Not in start-up time (that's icing on the cake, really) but in bottom-line request-processing throughput and latency.
>>Quote: "But “server code” today includes web apps that have to start fast. The 64-bit JIT currently in .NET isn’t always fast to compile your code, meaning you have to rely on other technologies such as NGen or background JIT to achieve fast program startup.