Thank you very much!

hey, do you have a dependency download happening in your script or bb.edn?

i shared my bb.edn (it's empty) and i dont think i am downloading anything in the script

(ns 
  (:require [clojure.java.shell :as shell :refer [sh]]
            [cheshire.core :as json]
            [ :as io]
            [clojure.string :as s]
            [taoensso.timbre :as timbre])
  (:import (java.time.format DateTimeFormatter)
           (java.time ZonedDateTime ZoneId Duration)))

@U7ERLH6JX

right thats weird, this error generally happens when bb is trying to download a dependency and needs java for it

looking at the stacktrace looks like a dep is being downloaded

look for maybe (deps/add-deps '{:deps ... in your code?

there is none of that in my code

i just ran empty script (just ns declaration, without requirements and code) - got the same exception

changed my bb.edn to

{:paths ["src"]}

ah interesting

thanks for the help

not sure what was happening there, maybe @U04V15CAJ has better ideas

Bb probably checks for non nil deps and then invokes deps.clj

something i learnt today too

We could check for empty? instead

PR welcome ;)

In general, for me i see bb for the following: • where i would use bash • where i would use python without the machine learning things • CI automation • glue scripts • CLI apps • need Clojure but the run time has to be less than few seconds at max • AWS lambdas

Also scripts with real multithreading (and soon virtual threads!) if thats important 😄

> CI automation how bb help you with CI?

> need Clojure but the run time has to be less than few seconds at max Does it speed up all kind of Clojure systems without any issues?

it only "speeds up" the start time as things are either compiled to native code or interpreted with low overhead. long time perf or things like tight loops with any day be faster on a JVM.

so the rule is: if you use pure bb it will be faster, but if you depend on third party libraries, then JVM will be faster. Do I understand this correctly?

bb can do third party libs, provided they follow certain rules. as for the faster bit, its mostly startup time and not necessarily runtime performance

I will ask in other way: Can I use bb with jar file to speed up cold start?

if the contents of the jar file is compatible with bb then yes.

I know GraalVM or how it is called can do it, but it has issues. I am curious if bb can speed up cold start (starting docker in cloud) which take for example 8 sec. to 2 seconds or something like that.

bb cannot execute arbritary code

> compatible What does it mean?

So can I use bb to speed up my regular systems or not? It is not clear for me.

but as I can understand I can’t use it in that way

so bb is a native compiled environment which interprets clojure unlike the usual clojure which emits JVM bytecodes, which runs differently. meaning it can interop with java code at run time etc. bb doesnt have the jvm so cant interop unless the java class is know ahead of time.

a lot of clojure libs are around java code or have clojure code which emit byte codes. such libs cannot be run on bb

https://book.babashka.org/#differences-with-clojure

list of things that are compatible: https://github.com/babashka/babashka/blob/master/doc/projects.md

oh so bb can’t use Java, only pure Clojure? > unless the java class is know ahead of time Do you mean author of bb include it into bb?

yes

ah ok now it is clear

thank you

bb is an interpreter and doenst have the full JVM infra anymore, hence the limitations

bb can do java if you compile it yourself 🙂

Is it simple to make my own bb working with deps.edn from the project?

The simple solution to speed cold start could be great

sure, but bb uses its own project system https://book.babashka.org/#project-setup

actually if someone will make such solution it will be awesome

if your code isnt too complex you can always have it in a single file and bb script.clj

its in a similar set of ideas like bash or python

I am thinking if bb can speed up cold starts in cloud for complex systems

8 sec of cold start means 8 sec longer response

which is huge

if it can be reduced to 1-3 sec. it makes a difference

but if it will became hard and complex, then I will not use it

complex code is okay too. you can use its project setup

thank you, I will back to this topic in “free time”

bb can produce a single script or a jar if you want too

https://book.babashka.org/#_uberscript

Maybe someone will make a “1 line solution” to prepare bb to run with project and do all things like get libraries from deps.edn by automate

that will be huge win

quite doable! 🙂

in the world of cloud and dynamic scaling multiple instances

keep in mind, the JVM isnt quick to start but is one of the fastest when running for a while. so optimise not only on start time but how long a thing runs. if its more than 4-5s, the JVM can already beat bb

JVM will probably outperform native code too, which has an even lower startup time than bb

i wouldnt write a long running server in rust for instance

> but is one of the fastest when running for a while Do you mean bb is slower in runtime?

so the JVM has the Just In Time compiler (JIT) which produces optimised assembly code based on how your code runs. its only possible when its running so ahead of time (AOT) languages like rust/go wont have these info. and bb is an interpreter, like python. it doesnt emit assembly

oh so bb works only with .clj files? not .jar?

it can do jars, provided then contain compatible code 🙂

they are just zips right

😱

but yeah if it has .class files, it cant. bb cant load bytecodes right.

So when compile my own bb can I make it start faster and work as fast as standard jar file compiled from Clojure including Java libraries?

ok, so my final understanding is:

bb can make cold start faster, but it makes runtime slower

yep. the whole reason it starts faster is probably also why its runtime is slower: it doesnt have the fancy machinery of the JVM

which now make use cases very clear

thank you for explanation

It should be written in first line of the doc to make people understand when use bb heh

i would highly recommend the https://www.youtube.com/watch?v=Nw8aN-nrdEk

> It should be written in first line of the doc to make people understand when use bb heh we can take it as a feedback, also PRs welcome!

we have a https://book.babashka.org/ too

out of my curiosity: is babashka name because author is from Russia? 😉

can ask the author @U04V15CAJ 😛

oh I didn’t notice he is an author!

good job 🙂

as far as i remember, its for the "gray" areas of bash, so the grandma reference, the word-play with bash

I'm not from Russia :)

babashka is just a nonsense name which sounded funny to me

also you can check out this https://www.youtube.com/watch?v=ZvOs5Ele6VE from me, mostly focusing on scripting and moving from the JVM to native to bb. also has a bb project made from scratch, live code!

its a talk at a Linux users group, so has some intro to clojure too, can skip it probably 😛

I am always curious how people are so creative to make names for they libraries. I am simple guy and name things in very raw way: for example https://github.com/kwladyka/form-validator-cljs While everyone have cool names for everything 🙂

its simple

😉

what do you think is really happening in the hammock?

also id recommend checking out #nbb too since you seem to be involved in cljs too!

Thanks. Although I hate node.js 🙂

its the best worst thing we have

We all hate it, that's why I tried to put some Clojure on top ;)