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![Install
$ lein immutant install [version]
Monday, March 19, 2012](https://image.slidesharecdn.com/immutantclojurewest-120319180315-phpapp02/85/Introducing-Immutant-26-320.jpg)
![Web
(require ‘[immutant.web :as web])
(defn my-handler [request]
{:status 200
:headers {"Content-Type" "text/html"}
:body "Hello from Immutant!"})
(web/start "/hi" my-handler)
Monday, March 19, 2012](https://image.slidesharecdn.com/immutantclojurewest-120319180315-phpapp02/85/Introducing-Immutant-38-320.jpg)
![Session Replication
(require ‘[immutant.web :as web]
‘[immutant.web.session :as iws])
(web/start "/"
(ring-session/wrap-session
handler
{:store (iws/servlet-store)}))
Monday, March 19, 2012](https://image.slidesharecdn.com/immutantclojurewest-120319180315-phpapp02/85/Introducing-Immutant-41-320.jpg)
![Messaging
(require ‘[immutant.messaging :as msg])
(msg/start "/queue/work")
(msg/start "/topic/news")
Monday, March 19, 2012](https://image.slidesharecdn.com/immutantclojurewest-120319180315-phpapp02/85/Introducing-Immutant-44-320.jpg)
![Producers
;;;; May be as complex as necessary
(msg/publish "/queue/work"
{:a "b" :c [1 2 3 {:foo 42}]})
Monday, March 19, 2012](https://image.slidesharecdn.com/immutantclojurewest-120319180315-phpapp02/85/Introducing-Immutant-46-320.jpg)
![Producers
;;;; Three message encodings:
;;;; :clojure :json :text
(msg/publish "/queue/work"
{:a "b" :c [1 2 3 {:foo 42}]}
:encoding :json)
Monday, March 19, 2012](https://image.slidesharecdn.com/immutantclojurewest-120319180315-phpapp02/85/Introducing-Immutant-48-320.jpg)
![Consumers
;;;; Block until message arrives
(let [task (msg/receive "/queue/work")]
(perform task))
Monday, March 19, 2012](https://image.slidesharecdn.com/immutantclojurewest-120319180315-phpapp02/85/Introducing-Immutant-50-320.jpg)
![Consumers
(defn upper-caser [s]
(msg/publish "/topic/upper"
(.toUpperCase s)))
;;;; Register a listener
(msg/listen "/queue/lower" upper-caser)
Monday, March 19, 2012](https://image.slidesharecdn.com/immutantclojurewest-120319180315-phpapp02/85/Introducing-Immutant-52-320.jpg)
![immutant.cache
(require ‘[immutant.cache :as ic])
(def a (ic/cache “foo” :replicated))
(def b (ic/cache “bar”))
(def c (ic/cache “foo”))
Monday, March 19, 2012](https://image.slidesharecdn.com/immutantclojurewest-120319180315-phpapp02/85/Introducing-Immutant-62-320.jpg)
![Memoization
(require ‘[immutant.cache :as ic])
(def memoized-fn (ic/memo slow-fn “foo”))
(memoized-fn 1 2 3)
(def c (ic/cache “foo”))
c => {[1 2 3] 42}
Monday, March 19, 2012](https://image.slidesharecdn.com/immutantclojurewest-120319180315-phpapp02/85/Introducing-Immutant-64-320.jpg)
![Explicit writes
(require ‘[immutant.cache :as ic])
(def opts {:ttl 2 :idle 1 :units :days})
(def c (ic/cache “foo”))
(ic/put c key value opts)
(ic/put-if-absent c key value opts)
(ic/put-if-present c key value opts)
(ic/put-if-replace c key old new opts)
(ic/delete c key)
Monday, March 19, 2012](https://image.slidesharecdn.com/immutantclojurewest-120319180315-phpapp02/85/Introducing-Immutant-65-320.jpg)
![Scheduling
(require ‘[immutant.jobs :as job])
;;;; Once a month
(job/schedule "newsletter"
"0 0 0 1 * ?"
news/monthly
:singleton true)
Monday, March 19, 2012](https://image.slidesharecdn.com/immutantclojurewest-120319180315-phpapp02/85/Introducing-Immutant-67-320.jpg)
![Scheduling
(require ‘[immutant.jobs :as job])
(job/at “name” “3m”
#(println “I fire after 3 minutes”))
(job/every “name” “1d”
#(println “I fire once a day”))
Monday, March 19, 2012](https://image.slidesharecdn.com/immutantclojurewest-120319180315-phpapp02/85/Introducing-Immutant-69-320.jpg)
![Daemons
(require ‘[immutant.daemons :as daemon])
(daemon/start "name" start-fn stop-fn)
Monday, March 19, 2012](https://image.slidesharecdn.com/immutantclojurewest-120319180315-phpapp02/85/Introducing-Immutant-71-320.jpg)
![Daemons
(def response (atom nil))
(defn start []
(reset! response
(twitter-statuses-filter
(terms)
url-scraper)))
(defn stop []
((:cancel (meta @response))))
(daemon/start "tweets" start stop
:singleton true)
Monday, March 19, 2012](https://image.slidesharecdn.com/immutantclojurewest-120319180315-phpapp02/85/Introducing-Immutant-72-320.jpg)
![mod_cluster
• An Apache module aware of JBoss
• Reverse proxy via AJP or HTTP[S]
• Uses load statistics and deployment
availability for intelligent routing
• Optional session affinity
• Failover
Monday, March 19, 2012](https://image.slidesharecdn.com/immutantclojurewest-120319180315-phpapp02/85/Introducing-Immutant-76-320.jpg)
Introducing Immutant
- 1. Jim Crossley jcrossley@redhat.com Creative Commons BY-SA 3.0 Monday, March 19, 2012
- 2. Agenda • Who, what, WHY? • A fake, real-life application • How? • API deep-dive • Clustering, etc Monday, March 19, 2012
- 3. Who? • Jim Crossley - @jcrossley3 • Toby Crawley - @tcrawley • Bob McWhirter - Director of Polyglot • JBoss by Red Hat Monday, March 19, 2012
- 4. What? • An app server for Clojure • Inspired by TorqueBox • Powered by JBoss AS7 • Started in September 2011 Monday, March 19, 2012
- 5. App Server? • Multiple apps running in same JVM • Isolation via classloaders • Shared common services Monday, March 19, 2012
- 6. Inspired by TorqueBox • Make Ring, not War • Clojure interfaces to JBoss middleware • No XML • Adapt AS7 to the Clojure development common practices Monday, March 19, 2012
- 7. AS7 is teh awesome! • Tomcat for web • HornetQ for messaging • Infinispan for caching • Quartz for scheduling • Distributed Transactions (XA) • Clustering • Management/Monitoring Monday, March 19, 2012
- 8. Certified, fwiw Java EE 6 Full Profile Monday, March 19, 2012
- 9. Why? • Reduce incidental complexity • Simplify deployment of non-trivial applications • Simplify clustering to achieve high- availability • Encapsulate JBoss services • Exploit the JVM Monday, March 19, 2012
- 10. Polyglot • Leverage the best tool on a single platform, regardless of language • “ruby in the front, java in the middle, clojure in the rear” • Red Hat is committed to it Monday, March 19, 2012
- 11. Maybe a fit? • If you’re already using Jetty, Memcached, RabbitMQ, and/or Cron • If you have a polyglot organization, especially Ruby and Java • If you must integrate with legacy Java EE Monday, March 19, 2012
- 12. Let’s Get Real CRUD can only take you so far Monday, March 19, 2012
- 13. Apps often require... • More than one web interface, e.g. administration • Background processing • Periodic maintenance • Dynamic data sources, e.g. REST • Services Monday, March 19, 2012
- 14. But... We’d still like to treat the integration of those components as a single, versioned application. Monday, March 19, 2012
- 15. Consider... • A tweet-analysis app • Filters the Twitter streaming API for brand keywords • Scrapes URL’s from the tweets • Stores weighted results of sentiment analysis Monday, March 19, 2012
- 16. Possible Components... • A web app for displaying impressions • An admin app for defining users • The Twitter streaming client • The URL scraper • A housekeeper to purge old data Monday, March 19, 2012
- 17. The Web Apps ;;;; Mount the ring handlers (web/start “/” brandy.web/app) (web/start “/admin” brandy.web/admin) Monday, March 19, 2012
- 18. The Message Queue ;;;; Where scrapers pick up their work (msg/start “/queue/tweets”) ;;;; The scrapers (msg/listen “/queue/tweets” brandy.msg/scrape) Monday, March 19, 2012
- 19. The Twitter Service ;;;; The work producer (daemon/start “streamer” brandy.stream/start brandy.stream/stop) Monday, March 19, 2012
- 20. The Recurring Job ;;;; The housekeeper (job/schedule “housekeeper” “0 0 0 * * ?” brandy.job/purge) Monday, March 19, 2012
- 21. immutant.clj ;; The ring handlers (web/start “/” brandy.web/app) (web/start “/admin” brandy.web/admin) ;; Where scrapers pick up their work (msg/start “/queue/tweets”) ;; The scrapers (msg/listen “/queue/tweets” brandy.msg/scrape) ;; The work producer (daemon/start “streamer” brandy.stream/start brandy.stream/stop) ;; The housekeeper (job/schedule “housekeeper” “0 0 0 * * ?” brandy.job/purge) Monday, March 19, 2012
- 22. immutant.clj ;; The ring handlers (web/start “/” brandy.web/app) (web/start “/admin” brandy.web/admin) ;; Where scrapers pick up their work (msg/start “/queue/tweets”) ;; The scrapers (msg/listen “/queue/tweets” brandy.msg/scrape) ;; The work producer (daemon/start “streamer” brandy.stream/start brandy.stream/stop) ;; The housekeeper (job/schedule “housekeeper” “0 0 0 * * ?” brandy.job/purge) Monday, March 19, 2012
- 23. immutant.clj ;; The ring handlers (web/start “/” brandy.web/app) (web/start “/admin” brandy.web/admin) ;; Where scrapers pick up their work (msg/start “/queue/tweets”) ;; The scrapers (msg/listen “/queue/tweets” brandy.msg/scrape) ;; The work producer (daemon/start “streamer” brandy.stream/start brandy.stream/stop) ;; The housekeeper (job/schedule “housekeeper” “0 0 0 * * ?” brandy.job/purge) Monday, March 19, 2012
- 24. Immutant how? Monday, March 19, 2012
- 25. Leiningen Plugin $ lein plugin install lein-immutant 0.6.0 Monday, March 19, 2012
- 26. Install $ lein immutant install [version] Monday, March 19, 2012
- 27. Install By default, the plugin installs Immutant beneath ~/.lein/immutant/ Monday, March 19, 2012
- 28. Run $ lein immutant run Monday, March 19, 2012
- 29. Deploy $ lein new myapp $ cd myapp $ lein immutant init $ $EDITOR immutant.clj $ lein immutant deploy Monday, March 19, 2012
- 30. Deploy A “deployment descriptor” is a glorified symlink written to jboss/standalone/deployments Its contents: {:root "/the/path/to/your/app"} Monday, March 19, 2012
- 31. Deploy Each app gets a dedicated Clojure runtime and classpath containing resolved dependencies, src, lib, and resources. Monday, March 19, 2012
- 32. project.clj (defproject myapp "1.2.3" ... :immutant {:init myapp.core/initialize :resolve-dependencies true :context-path "/" :swank-port 4111 :nrepl-port 4112}) Monday, March 19, 2012
- 33. Overlay $ lein immutant overlay torquebox $ export TORQUEBOX_HOME=$IMMUTANT_HOME Monday, March 19, 2012
- 34. The API immutant namespaces Monday, March 19, 2012
- 35. The API • Dynamic by design • No static xml files or annotations • Modules • Web • Messaging • Caching • Scheduling • Daemons Monday, March 19, 2012
- 36. immutant.web ring Monday, March 19, 2012
- 37. Web • Supports any Ring-based handler • Ring middleware to expose the Servlet session • Multiple web apps may share the same lifecycle via “subcontexts” Monday, March 19, 2012
- 38. Web (require ‘[immutant.web :as web]) (defn my-handler [request] {:status 200 :headers {"Content-Type" "text/html"} :body "Hello from Immutant!"}) (web/start "/hi" my-handler) Monday, March 19, 2012
- 39. Context paths project.clj (defproject myapp "1.2.3" ...) immutant.clj (web/start "/" main) ;;;; http://localhost:8080/myapp/ (web/start "/admin" admin) ;;;; http://localhost:8080/myapp/admin Monday, March 19, 2012
- 40. Context paths project.clj (defproject myapp "1.2.3” :immutant {:context-path "/"}) immutant.clj (web/start "/" main) ;;;; http://localhost:8080/ (web/start "/admin" admin) ;;;; http://localhost:8080/admin Monday, March 19, 2012
- 41. Session Replication (require ‘[immutant.web :as web] ‘[immutant.web.session :as iws]) (web/start "/" (ring-session/wrap-session handler {:store (iws/servlet-store)})) Monday, March 19, 2012
- 42. immutant.messaging hornetq Monday, March 19, 2012
- 43. Messaging publish-subscribe point-to-point Monday, March 19, 2012
- 44. Messaging (require ‘[immutant.messaging :as msg]) (msg/start "/queue/work") (msg/start "/topic/news") Monday, March 19, 2012
- 45. Producers ;;;; Content may be any serializable ;;;; data structure (msg/publish “/queue/work” anything) Monday, March 19, 2012
- 46. Producers ;;;; May be as complex as necessary (msg/publish "/queue/work" {:a "b" :c [1 2 3 {:foo 42}]}) Monday, March 19, 2012
- 47. Producers ;;;; Support priority and time-to-live (msg/publish “/queue/work” a-message :priority :high :ttl 1000) Monday, March 19, 2012
- 48. Producers ;;;; Three message encodings: ;;;; :clojure :json :text (msg/publish "/queue/work" {:a "b" :c [1 2 3 {:foo 42}]} :encoding :json) Monday, March 19, 2012
- 49. Messaging With TorqueBox, messages comprised of standard collections and types are transparently interoperable between Clojure and Ruby in either direction. Monday, March 19, 2012
- 50. Consumers ;;;; Block until message arrives (let [task (msg/receive "/queue/work")] (perform task)) Monday, March 19, 2012
- 51. Consumers ;;;; Create a lazy sequence of messages (take 4 (msg/message-seq “/queue/foo”)) Monday, March 19, 2012
- 52. Consumers (defn upper-caser [s] (msg/publish "/topic/upper" (.toUpperCase s))) ;;;; Register a listener (msg/listen "/queue/lower" upper-caser) Monday, March 19, 2012
- 53. Messaging Automatic retries, failover and load-balancing when clustered. Monday, March 19, 2012
- 54. immutant.cache infinispan Monday, March 19, 2012
- 55. Distributed Cache • Backed by Infinispan data grid • Implements core Clojure interfaces •core.cache/CacheProtocol • core.memoize store Monday, March 19, 2012
- 56. Infinispan • Eviction: FIFO, LRU • Expiration: time-to-live, idle time • Persistence: write-through/behind • Transactional: JTA/XA • MVCC-based concurrency • Flexible clustering Monday, March 19, 2012
- 57. Cache Modes • :local - non-clustered • Clustered • :invalidated - no data shared • :replicated - all data shared • :distributed - linear scalability Monday, March 19, 2012
- 58.
- 59.
- 60.
- 61. immutant.cache • All caches have a name and a mode (:local, :invalidated, :replicated, :distributed) • Like-named Immutant caches are backed by the same Infinispan cache Monday, March 19, 2012
- 62. immutant.cache (require ‘[immutant.cache :as ic]) (def a (ic/cache “foo” :replicated)) (def b (ic/cache “bar”)) (def c (ic/cache “foo”)) Monday, March 19, 2012
- 63. immutant.cache (def c (ic/cache “foo”)) (assoc c :a 1) (merge c {:b 2 :c 3}) (dissoc c :c) c => {:a 1, :b 2} Monday, March 19, 2012
- 64. Memoization (require ‘[immutant.cache :as ic]) (def memoized-fn (ic/memo slow-fn “foo”)) (memoized-fn 1 2 3) (def c (ic/cache “foo”)) c => {[1 2 3] 42} Monday, March 19, 2012
- 65. Explicit writes (require ‘[immutant.cache :as ic]) (def opts {:ttl 2 :idle 1 :units :days}) (def c (ic/cache “foo”)) (ic/put c key value opts) (ic/put-if-absent c key value opts) (ic/put-if-present c key value opts) (ic/put-if-replace c key old new opts) (ic/delete c key) Monday, March 19, 2012
- 66. immutant.jobs quartz Monday, March 19, 2012
- 67. Scheduling (require ‘[immutant.jobs :as job]) ;;;; Once a month (job/schedule "newsletter" "0 0 0 1 * ?" news/monthly :singleton true) Monday, March 19, 2012
- 68. Scheduling “Fire every half hour from 10am until 1pm on the third Friday of each month” 0 */30 10-13 ? * FRI#3 Seconds Minutes Hours DOM Month DOW Year 1-7 1-12 1970- 1-31 SUN- 0-59 0-59 0-23 JAN- 2099 ?LW SAT DEC empty ?L# Monday, March 19, 2012
- 69. Scheduling (require ‘[immutant.jobs :as job]) (job/at “name” “3m” #(println “I fire after 3 minutes”)) (job/every “name” “1d” #(println “I fire once a day”)) Monday, March 19, 2012
- 70. immutant.daemons long-running services Monday, March 19, 2012
- 71. Daemons (require ‘[immutant.daemons :as daemon]) (daemon/start "name" start-fn stop-fn) Monday, March 19, 2012
- 72. Daemons (def response (atom nil)) (defn start [] (reset! response (twitter-statuses-filter (terms) url-scraper))) (defn stop [] ((:cancel (meta @response)))) (daemon/start "tweets" start stop :singleton true) Monday, March 19, 2012
- 73. Clustering simple horizontal scaling Monday, March 19, 2012
- 74. Clustering $ lein immutant run --clustered Monday, March 19, 2012
- 75. Clustering • Session replication • Robust, load-balanced message distribution • HA Singleton • HA Jobs • Infinispan Monday, March 19, 2012
- 76. mod_cluster • An Apache module aware of JBoss • Reverse proxy via AJP or HTTP[S] • Uses load statistics and deployment availability for intelligent routing • Optional session affinity • Failover Monday, March 19, 2012
- 77.
- 78. Coming soon • Distributed Transactions (XA) • OpenShift integration • Websockets • Better remote support • Domain Mode (cluster management) Monday, March 19, 2012
- 79. http://immutant.org #immutant @immutants Monday, March 19, 2012