Scripting-language for JVM with fast initialization

Question

I have a simple java application that gets jmx connection url, object name and attribute name as inputs and outputs attribute value. This application runs hundreds of times every minute and has strict running time limitations. Recently many corner cases appeared (converting milliseconds to seconds, folding a list, etc.) and recompiling and redistributing this application becomes tedious. So i've decided to switch to some scripting language with support for JMX.

I've tried groovy, jython and clojure and found that their initialization time is lengthy (around 0.9/1.2/3.5 for groovy/clojure/jython).

Is there anything with faster initialization speed or is there a way to decrease initialization time of these laguages without loading them from java?

So you're constrained by startup time in an application which is launched several hundred times a second? How about doing away with the repeated initialization and making it a daemon? — , Sep 18 '12 at 19:24
Hundred times a minute, not a second. This application is lunched by daemon and there is no way of overcoming this, application must be started every time by this daemon. I though of making a proxy that would by launched by daemon and would connect to another daemon, but maintaining another daemon would be harder than maintaining java. — Blin, Sep 18 '12 at 20:00

Nicolas Modrzyk · Answer 1 · 2012-09-25T03:37:30.673

2

Nowawadays, jark seems to be a nice solution.

Write a clojure script like

(ns jarkserver)

(require '[clojure.tools.nrepl :as nrepl])

(defn -main
[& args]
(nrepl/start-server 9000)
(.join (Thread/currentThread)))

Start it with:

 lein run -m jarkserver

Then start a REPL with:

 jark repl

or run your clojure script with:

 jark <path_to_clojure_script>

or just execute some clojure code inline:

 jark -e "(+ 1 1)"

Edit: An easier way to start the Jark server would be:

jark -cp lib/*:lib/dev/*:* -p 9000 server start

edited Sep 25 '12 at 03:37

answered Sep 20 '12 at 08:28

Nicolas Modrzyk

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This seems like a nice idea, is there anything like this for groovy or jython? – Blin Sep 25 '12 at 09:46
I've struggled for quite a while to make jark(0.4.3 the latest on the site) work. Evaluation through "-e" works great, but i was unable to run scripts. When trying ./jark test.clj i get "jark: No such module test.clj". – Blin Oct 20 '12 at 11:20
@Blin I had the same problem, my mistake was that I'd started the jark server in a different directory, by invoking jark with my script's full path everything worked. (FYI you can check jark's current working directory with `jark -e (. System getProperty \"user.dir\")`). – thatismatt Mar 15 '13 at 16:10

score 2 · Accepted Answer · answered Oct 20 '12 at 13:14

2

I have found a solution that should work across all java scripting languages it is nailgun. It has the same principle as jerk and cake suggested in other answers but it runs arbitary java classes.

This blog post has a great instruction on how to run jython scripts with nailgun and i am sure it can be applied to other scripting languages.

answered Oct 20 '12 at 13:14

Blin

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For an example on how to use nailgun with clojure, check http://stackoverflow.com/a/19107684/709537 – Evgeniy Berezovsky Oct 01 '13 at 05:30

Alex D · Answer 3 · 2012-09-19T18:36:08.863

0

Apparently Cake (https://github.com/flatland/cake), for Clojure, includes a Clojure script launcher which uses an already-initialized JVM which runs in the background. You'll have to look up the details yourself, because I've never used it and don't know anything specific about it. But apparently it cuts way down on startup time.

edited Sep 19 '12 at 18:36

answered Sep 19 '12 at 18:00

Alex D

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score 0 · Answer 4 · answered Aug 10 '20 at 20:20

Other options (I am not familiar with them):

Other avenues worth exploring (in decreasing promisingness) :

https://github.com/eraserhd/rep (not really made for scripting, but maybe can be adapted for it)
cljs (lumo or planck)
graal
https://github.com/analyticbastard/clj-on-k8s-quickstart
http://blog.gilliard.lol/2017/10/04/AppCDS-and-Clojure.html

Scripting-language for JVM with fast initialization

4 Answers4