4 ms·

Can someone please remind me why interpreter startup time matters? Maybe it's because I originally came from Java-land. I really don't get it.

by po 17y ago

bad_user 17y ago
It matters in some contexts. For quick scripts that you invoke from the console, it's painful to wait a couple of seconds just to see if it does something. For web servers, if you're using something like Google's App Engine which starts VM instances as needed, or stops them when there's no traffic, users have experienced what is called a "loading requests" ... which is basically a very slow request or requests throwing DeadlineExceededExceptions. That's because the startup time of the runtime is very slow, especially when you have big dependencies like JRuby ... see this blog post for instance ... http://googleappengine.blogspot.com/2009/12/request-performance-in-java.html http://googleappengine.blogspot.com/2009/12/request-performa...
viraptor 17y ago
Ok - so you've got a script that runs in ½s, but it integrates with some .net stuff, so you run it under ironpython. Instead of getting the result straight away, you have to wait 3s (startup + run). It will be at least annoying if you rely on that script many times during the day.
jules 17y ago
It's stupid to have to wait >2 secs from pressing F5 to seeing the results of your code. Maybe not for a Java programmer, but if you're used to instant results from CPython it's annoying.
thibaut_barrere 17y ago
One case that comes to mind - quite often when I do unit-testing in JRuby, and run a single test from the command-line, the test will take 1sec with JRuby vs almost nothing in regular Ruby. So I find myself running the individual test using MRI Ruby while developing, although the whole test run will be done with JRuby in the end, just because of startup time.
kingkilr 17y ago
Mercurial, and the others of that ilk.
riobard 17y ago
I use Python quite a lot before I try Scala (on JVM). I have to say the slow Scala interpreter startup (due to JVM, again) really pisses me off for scripting in Scala (otherwise it's a nice language for scripting).
torial 17y ago
If memory serves, this was important for cgi scripting -- where a new page hit launched some python code (and hence a new interpreter process).
gtani 17y ago
the scala and clojure folks have spent a lot of bandwidth discussing: http://groups.google.com/group/clojure/browse_frm/thread/33f80f1bb8277351# http://groups.google.com/group/clojure/browse_frm/thread/33f... http://stackoverflow.com/questions/1316056/how-to-reduce-scala-java-startup-overhead http://stackoverflow.com/questions/1316056/how-to-reduce-sca... http://www.assembla.com/spaces/clojure/tickets/81-GC--Issue-78----patch-to-improve-startup-time-on-low-end-hardware http://www.assembla.com/spaces/clojure/tickets/81-GC--Issue-... http://groups.google.com/group/clojure/browse_thread/thread/c40b2973109db24# http://groups.google.com/group/clojure/browse_thread/thread/...

Can someone please remind me why interpreter startup time matters? Maybe it's because I originally came from Java-land. I really don't get it.

by po 17y ago

Can someone please remind me why interpreter startup time matters? Maybe it's because I originally came from Java-land. I really don't get it.

bad_user 17y ago

It matters in some contexts. For quick scripts that you invoke from the console, it's painful to wait a couple of seconds just to see if it does something. For web servers, if you're using something like Google's App Engine which starts VM instances as needed, or stops them when there's no traffic, users have experienced what is called a "loading requests" ... which is basically a very slow request or requests throwing DeadlineExceededExceptions. That's because the startup time of the runtime is very slow, especially when you have big dependencies like JRuby ... see this blog post for instance ... http://googleappengine.blogspot.com/2009/12/request-performance-in-java.html http://googleappengine.blogspot.com/2009/12/request-performa...

viraptor 17y ago

Ok - so you've got a script that runs in ½s, but it integrates with some .net stuff, so you run it under ironpython. Instead of getting the result straight away, you have to wait 3s (startup + run). It will be at least annoying if you rely on that script many times during the day.

jules 17y ago

It's stupid to have to wait >2 secs from pressing F5 to seeing the results of your code. Maybe not for a Java programmer, but if you're used to instant results from CPython it's annoying.

thibaut_barrere 17y ago

One case that comes to mind - quite often when I do unit-testing in JRuby, and run a single test from the command-line, the test will take 1sec with JRuby vs almost nothing in regular Ruby. So I find myself running the individual test using MRI Ruby while developing, although the whole test run will be done with JRuby in the end, just because of startup time.

kingkilr 17y ago

Mercurial, and the others of that ilk.

riobard 17y ago

I use Python quite a lot before I try Scala (on JVM). I have to say the slow Scala interpreter startup (due to JVM, again) really pisses me off for scripting in Scala (otherwise it's a nice language for scripting).

torial 17y ago

If memory serves, this was important for cgi scripting -- where a new page hit launched some python code (and hence a new interpreter process).

gtani 17y ago

the scala and clojure folks have spent a lot of bandwidth discussing: http://groups.google.com/group/clojure/browse_frm/thread/33f80f1bb8277351# http://groups.google.com/group/clojure/browse_frm/thread/33f... http://stackoverflow.com/questions/1316056/how-to-reduce-scala-java-startup-overhead http://stackoverflow.com/questions/1316056/how-to-reduce-sca... http://www.assembla.com/spaces/clojure/tickets/81-GC--Issue-78----patch-to-improve-startup-time-on-low-end-hardware http://www.assembla.com/spaces/clojure/tickets/81-GC--Issue-... http://groups.google.com/group/clojure/browse_thread/thread/c40b2973109db24# http://groups.google.com/group/clojure/browse_thread/thread/...