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Work on an enterprise-sized "app", the JVM starts seeming "heavy". It feels super slow (and memory greedy, and you have to make sure it has enough of the right

by Jach 10y ago

Work on an enterprise-sized "app", the JVM starts seeming "heavy". It feels super slow (and memory greedy, and you have to make sure it has enough of the right 'type' of memory) in executing on a whole (when it gets going it can do limited, specific things quite fast) and for productivity, as does all the tooling around it. Unless perhaps you're Google and you have server farms constantly compiling crap and so on so devs don't have to notice as much. Most of the negative feelings are probably the fault of having a ginormous app in the first place, I'd likely feel similarly about C++. Still, even when it's just a somewhat-large app (like a database, or an IDE) I've felt it in Java whereas working on a similarly large app in other languages doesn't have the same feeling. I've never really felt it when just writing a REST/SOAP API that's effectively a thin wrapper around some DB calls. Like a blog could be, but there are many other similarly small things. But those sorts of small problems can be done effectively in most any language, and 'heaviness' is probably very low on one's priority list... I think there's an incentive with more dynamic languages to decompose your software into smaller bits. When the language gives you the ability to "script" that helps even more. You don't need to bundle everything into an uberjar, you can run things independently, and therefore you don't even need all of the sources locally, just what you need to do your particular bit of data processing. It's possible to do this with Java and multiple JVMs, but it's hard, the incentives aren't there. Unfortunately I don't have experience with Clojure in the large to say whether it helps make the JVM feel lighter, from my side projects it seems like it could but I don't know if the community is going that way. Lispy languages have different incentives since they let you build from the bottom up so well.

stevedonovan 10y ago
Yes, it's not my preferred platform at all but we all inherit projects. By leaning too heavily on the _dynamic_ aspects of Java (like reflection) it is possible to get Python-like speeds and constantly running the risk of OOM. But with better tooling than Python, at least. (For small languages that interop with the JVM, I must say I had a lot of fun with LuaJava - Swing was actually pleasant)
mike_hearn 10y ago
I think a part of the reputation of Java being big and slow comes from its popularity in the enterprise. This is partly because in that space you're usually writing apps for a captive audience (your fellow employees) so there isn't much incentive to optimise. The business managers understand things like "the app has feature X by date Y" but don't really understand or care about "it is productive to develop on this app" or "the app uses half as much memory as last month". Those things make the lives of developers nicer, but don't change much about the business. Moreover, I think enterprise software managers often don't really have a grip on how much work needs to be done or how long it should take. So you can get situations where a team of say 10 people is staffed up to build an in house app, they deliver it, there are some improvements that can be made, they deliver the improvements, etc. After a few years the app is largely in maintenance mode and doesn't need much done to it, but ... who wants to fire the loyal employees who understand the app? Unless there is another app of roughly the same size and type waiting in the wings, what can happen is the team starts doing busywork. The managers don't notice because they aren't programmers to begin with and can't tell the difference between "creating a new in house framework because no reasonable alternative exists" and "creating a new in house framework because we're bored". So over time enterprise software can bloat to extreme levels. Combined with Java's verbosity, and the fact that a long time ago it really was very slow, you get a platform with a reputation for ponderousness that is only partly deserved.

by Jach 10y ago

stevedonovan 10y ago

Yes, it's not my preferred platform at all but we all inherit projects. By leaning too heavily on the _dynamic_ aspects of Java (like reflection) it is possible to get Python-like speeds and constantly running the risk of OOM. But with better tooling than Python, at least. (For small languages that interop with the JVM, I must say I had a lot of fun with LuaJava - Swing was actually pleasant)

mike_hearn 10y ago

I think a part of the reputation of Java being big and slow comes from its popularity in the enterprise. This is partly because in that space you're usually writing apps for a captive audience (your fellow employees) so there isn't much incentive to optimise. The business managers understand things like "the app has feature X by date Y" but don't really understand or care about "it is productive to develop on this app" or "the app uses half as much memory as last month". Those things make the lives of developers nicer, but don't change much about the business. Moreover, I think enterprise software managers often don't really have a grip on how much work needs to be done or how long it should take. So you can get situations where a team of say 10 people is staffed up to build an in house app, they deliver it, there are some improvements that can be made, they deliver the improvements, etc. After a few years the app is largely in maintenance mode and doesn't need much done to it, but ... who wants to fire the loyal employees who understand the app? Unless there is another app of roughly the same size and type waiting in the wings, what can happen is the team starts doing busywork. The managers don't notice because they aren't programmers to begin with and can't tell the difference between "creating a new in house framework because no reasonable alternative exists" and "creating a new in house framework because we're bored". So over time enterprise software can bloat to extreme levels. Combined with Java's verbosity, and the fact that a long time ago it really was very slow, you get a platform with a reputation for ponderousness that is only partly deserved.