GraalVM challenges the status quo on the JVM. This newly-released JIT compiler brings substantial speed improvements and support for polyglot applications. It also allows us to translate our JVM bytecode into self-contained native binaries. In this session we’ll explore GraalVM’s potential. We’ll focus on Clojure, but our discussion will apply to many more programming languages. We’ll use GraalVM to build small native binaries. We’ll discuss the method’s limitations and their impact. Finally, we’ll build complete Clojure web apps weighing a fraction of their traditional JVM incarnations.

1. GraalVM: Fast,
Polyglot, Native
21.11.2018 // CODEMOTION BERLIN
Jan Stępień
@janstepien
janstepien.com

2. JAN STĘPIEŃ
Senior Consultant
jan.stepien@innoq.com
Functional Programming
Property-Based Testing
Architecture and Development

3. Some background

4. Ahead-of-time compilation
*.java *.clj *.scala
*.class

5. Ahead-of-time compilation
*.class
Just-in-time compilation
Native machine code

6. HotSpot
JIT compiling since 1999

7. JEP 243
JVM Compiler Interface
JD
K
9

8. Graal
A compiler written in Java

9. graalvm.org

10. Three main target groups
JVM engineers
Authors of languages
Programmers and end users

11. Architecture

12. Truffle
TruffleRuby
GraalVM
JVMCI
GraalJVM

13. Three main target groups
JVM engineers
Authors of languages
Programmers and end users

14. Polyglot VM and tooling
Faster execution
Native compilation
Programmers and end users

15. Native Java

17. public class HelloWorld {
public static void main(String[] args) {
System.out.println("👋 Berlin");
}
}

18. $ time java HelloWorld
👋 Berlin
0.14 real 0.13 user 0.03 sys
29M maximum resident set size

19. $ native-image HelloWorld
classlist: 3,196.20 ms
⋮
image: 1,693.59 ms
write: 472.40 ms
[total]: 44,197.16 ms

20. $ time ./HelloWorld
👋 Berlin
0.00 real 0.00 user 0.00 sys
4M maximum resident set size

22. Ahead-of-time
compilation
Just-in-time
compilation
Slower startup
Higher top speed
High memory usage
Faster startup
Lower top speed
Low memory usage

23. Native Clojure

24. $ docker inspect ubuntu
| jq .[0].Size

25. (ns pprintin.main
(:require [clojure.pprint :refer [pprint]])
(:gen-class))
(defn -main [& path]
(-> (read *in*)
(get-in (mapv read-string path))
pprint))

26. $ echo {:a [5 3]}
| time java -jar pprint.jar :a 1
3
1.51 real
112MB maximum resident set size

27. $ echo {:a [5 3]}
| java -XX:TieredStopAtLevel=1
-jar pprint.jar :a 1
3
1.06 real
96MB maximum resident set size

28. $ echo {:a [5 3]}
| time lumo pprint.cljs :a 1
3
0.56 real
128MB maximum resident set size

29. $ native-image --no-server
--static -jar pprint.jar
classlist: 3,596.11 ms
(...)
image: 4,671.96 ms
write: 14,763.97 ms
[total]: 122,614.21 ms

30. $ echo {:a [5 3]}
| time ./pprint :a 1
3
0.01 real
12MB maximum resident set size

31. Time Memory
JVM 1.10 s 100 MB
JS 0.60 s 130 MB
Native 0.01 s 12 MB

32. Command line utilities

33. (ns json2edn.core
(:require [clojure.data.json :as json]))
(defn -main []
(->> (repeatedly #(json/read *in*
:key-fn keyword
:eof-error? false
:eof-value ::eof))
(take-while #(not= ::eof %))
(run! prn)))
;; See also Taylor Wood’s piece at
;; blog.taylorwood.io/2018/05/02/graal-clojure

34. $ cat package.json | time json2edn
{:description "Check if a value is an object",
:engines {:node ">=0.10.0"}, :license "MIT",
:repository "sindresorhus/is-obj",
:name "is-obj", :scripts {:test "xo && ava"},
:keywords ["obj" "object" "is" "check" "test"
"type"], :author {:name "Sindre Sorhus",
:email "sindresorhus@gmail.com", :url
"sindresorhus.com"}, :files ["index.js"],
:version “1.0.1"}
0.01 real
10MB maximum resident set size

36. (require '[spec-provider.provider :as sp])
(def inferred-specs
(sp/infer-specs
[{:a 8 :b "foo" :c :k}
{:a 10 :b "bar" :c "k"}
{:a 1 :b "baz" :c "k"}]
:toy/small-map))
(sp/pprint-specs inferred-specs 'toy ’s)
;; Results in the following being printed
(s/def ::c (s/or :keyword keyword? :string string?))
(s/def ::b string?)
(s/def ::a integer?)
(s/def ::small-map (s/keys :req-un [::a ::b ::c]))

37. (ns spec-provider.main
(:require [spec-provider.provider :as sp]
[clojure.string :as str]
[clojure.edn :as edn])
(:gen-class))
(defn -main
[spec-name]
(let [kw (as-keyword spec-name)
read-one (edn/read {:eof ::eof} *in*)
samples (sequence
(take-while (complement #{::eof}))
(repeatedly read-one))
specs (sp/infer-specs samples kw)]
(sp/pprint-specs specs (namespace kw) 's))))

39. $ cat node_modules/*/package.json
| json2edn | spec-provider :node/package | zprint
;; ...
(s/def ::repository
(s/or :map (s/keys :req-un [::type ::url])
:simple string?))
(s/def ::npm string?)
(s/def ::node string?)
(s/def ::engines (s/keys :req-un [::node] :opt-un [::iojs ::npm]))
(s/def ::description string?)
(s/def ::package
(s/keys :req-un [::description ::name ::repository ::version]
:opt-un [::author ::bin ::browser ::bugs ::contributors
::dependencies ::devDependencies ::engines
::files ::homepage ::icon ::keywords ::license
::main ::maintainers ::optionalDependencies
::peerDependencies ::scripts]))
0.29 real
103MB maximum resident set size

40. A simple Clojure web app

41. $ curl -i http://localhost:8080/kv/city -X PUT -d val=Berlin
HTTP/1.1 201 Created
Content-Type: application/octet-stream
Content-Length: 8
Server: http-kit
Date: Mon, 03 Sep 2018 16:04:22 GMT
Berlin
$ curl -i http://localhost:8080/kv/city
HTTP/1.1 200 OK
Content-Type: application/octet-stream
Content-Length: 8
Server: http-kit
Date: Mon, 03 Sep 2018 16:04:27 GMT
Berlin

42. (ns webkv.main
(:require [org.httpkit.server :as http]
[ring.middleware.defaults
:refer [wrap-defaults
api-defaults]]
[bidi.ring :refer [make-handler]])
(:gen-class))
;; We want to be sure none of our calls relies
;; on reflection. Graal does not support them.
(set! *warn-on-reflection* 1)
;; This is where we store our data.
(def ^String tmpdir
(System/getProperty "java.io.tmpdir"))
;; That's how we find a file given a key.
;; Keys must match the given pattern.
(defn file [^String key]
{:pre [(re-matches #"^[A-Za-z-]+$" key)]}
(java.io.File. tmpdir key))
;; Here we handle GET requests. We just
;; read from a file.
(defn get-handler
[{:keys [params]}]
{:body (str (slurp (file (params :key))) "n")})
;; This is our PUT request handler. Given
;; a key and a value we write to a file.
(defn put-handler
[{:keys [params]}]
(let [val (params :val)]
(spit (file (params :key)) val)
{:body (str val "n") , :status 201}))
;; Here's the routing tree of our application.
;; We pick the handler depending on the HTTP
;; verb. On top of that we add an extra middle-
;; ware to parse data sent in requests.
(def handler
(-> ["/kv/" {[:key] {:get #'get-handler
:put #'put-handler}}]
(make-handler)
(wrap-defaults api-defaults)))
;; Finally, we've got all we need to expose
;; our handler over HTTP.
(defn -main []
(http/run-server handler
{:port 8080})
(println "🔥 http://localhost:8080"))

43. Docker images

44. FROM ubuntu AS BASE
RUN apt-get update
RUN apt-get install -yy curl leiningen build-essential zlib1g-dev
RUN cd /opt && curl -sL https://github.com/.../graalvm.tar.gz
| tar -xzf -
ADD project.clj .
RUN lein deps
ADD src src
RUN lein uberjar
RUN /opt/graalvm-ce-1.0.0-rc5/bin/native-image
-H:EnableURLProtocols=http --static --no-server
-cp target/webkv-0.0.0-standalone.jar webkv.main
FROM scratch
COPY --from=BASE /webkv.main /
CMD ["/webkv.main"]
13
M
B

45. How Is That Even Possible

46. Time Memory
JVM 1.10 s 100 MB
JS 0.60 s 130 MB
Native 0.01 s 12 MB

48. static {
...
}
initialiser
Static
class

49. https://blog.ndk.io/clojure-compilation

51. GraalVM: Fast,
Polyglot, Native
Jan Stępień
@janstepien
janstepien.com
21.11.2018 // CODEMOTION BERLIN

52. This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
https://creativecommons.org/licenses/by-nc-sa/3.0/