Effective warmup strategy for Nashorn - JDK-8u40-b25

Kunal Cholera kcholera at linkedin.com
Mon Mar 16 22:22:58 UTC 2015

Hi Hannes,

Thanks for your reply. We will look into your suggestions, there are few questions as Chris emailed earlier  

Any insights from trying the scripts I sent earlier ?

From: Hannes Wallnoefer [hannes.wallnoefer at oracle.com]
Sent: Wednesday, March 11, 2015 3:06 AM
To: Kunal Cholera; nashorn-dev at openjdk.java.net
Subject: Re: Effective warmup strategy for Nashorn - JDK-8u40-b25

Hi Kunal,

I'm currently loking at the benchmark scripts you posted.

One approach you should try is to use a single Nashorn ScriptEngine with
multiple bindings (i.e. JS global objects). This allows Nashorn to share
compiled classes among multiple threads. It's probably the best
improvement you can make to startup and warmup time if you're using
multiple JS environments on multiple threads. On the other hand, it may
reduce top performance a little bit because of added polymorphism.

I've written about this in my recent Nashorn blog post, it also contains
demo code for how to set up the script engine for multiple threads:


I hope this helps. I'll get back to you when I'm done trying your scripts.


Am 2015-03-11 um 02:52 schrieb Kunal Cholera:
> Hello Nahsorn dev team,
> Currently our warmup strategy does the following - before our application starts serving request to real users we create 24 Nashorn instances. We are limiting to 24 as we have 24 CPU cores per machine in production. We then load the javascript files into this nashorn instances to setup the context for javascript execution. We then execute each of these javascript 2000 times with mock data to warmup the execution times.
> We have observed it takes about 4000 iterations[1] to reach optimal performance. See the graph here that shows 4000 javascript executions on 1 javascript file -
> https://drive.google.com/file/d/0B5PpdCJ7YycqbDJBWGRRVjRsYVU/view?usp=sharing
> Three questions
> 1.What is the best way to quickly warm-up to reach optimal performance in fewer iterations ?
> 2. Is there a better way to warmup using fixture data as opposed to fake data which we have to maintain ?
> 3. Is there a way to clone 1 nashorn instances that is warmed up so that we can avoid doing the same warmup for other nashorn instances ?
> [1]
> Steps to reproduce these performance numbers -
> Download this ziphttps://drive.google.com/file/d/0B5PpdCJ7YycqMWlVQ0FsNlozcTA/view?usp=sharing which has the following four files
> 1. bench.js - the benchmarking script
> 2. hp.js - the javascript we want to execute on Nashorn
> 3. hp.json - the data we want to use while executing our script hp.js
> 4. dust-full.js - library needed to execute hp.js script
> I am using "1.8.0_40-ea" Java(TM) SE Runtime Environment (build 1.8.0_40-ea-b25 on 8 core redhat linux machine ).
> Please advise.
> Thanks
> Kunal Cholera

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