Coordinating non blocking io melb-clj
•
0 gefällt mir•656 views
This document discusses various approaches to coordinating asynchronous HTTP requests and non-blocking I/O in a web application built with Clojure and HttpKit. It presents several solutions using promises and monads to handle asynchronous operations like making a payment on a bill by first retrieving a credit card token, then making a payment, and finally retrieving updated bill details. The solutions range from synchronous code to fully asynchronous approaches using raw promises, promise monads, and chained promises.
Empfohlen
Weitere ähnliche Inhalte
Ähnlich wie Coordinating non blocking io melb-clj
Ähnlich wie Coordinating non blocking io melb-clj (20)
Kürzlich hochgeladen
Kürzlich hochgeladen (20)
Coordinating non blocking io melb-clj
- 1. COORDINATING NON-BLOCKING IO AND ASYNC HTTP RESPONSES
- 3. WHAT IS THE WEB STACK • • • HttpKit as web server Compojure for routing HttpKit for non-blocking http requests
- 4. REACTIVE APPROACH PREFERRED We are not using either Functional Reactive Programming or Reactive Programming libraries. Eg. Rx.java • May satisfy other more broad definitions of reactive • Are making better use of threads than traditional approaches •
- 5. Make a payment on a bill - Not necessarily a full payment ! POST /bills/:bill-id/payments Session: user-id Post Data: amount ! 1. Get credit card token for user 1.1. Send request to payment gateway 2. Find how much was left to be payed ! If payment is success: render amount remaining on bill If payment fails: render error
- 6. CANDIDATES • Synchronous promises • core.async • Promise monad let/do • Lamina • Promise monad chain/lift- • Meltdown m-2 pipeline (LMAX Disrupter) • Raw promises • Pulsar promises • Raw callbacks • Pulsar Actors
- 7. SOLUTION 0: SYNCHRONOUS (GET "/bills/:bill-‐id/payments" [bill-‐id user-‐id amount] (let [token (auth/card-‐token user-‐id) details (bill/details bill-‐id) transaction (payment/bill bill-‐id amount @token)] (if (success? @transaction) (render-‐remaining-‐response @details amount) error-‐response)))
- 8. SOLUTION 1: PROMISE MONAD LET/DO (GET "/bills/:bill-‐id/payments" [bill-‐id user-‐id amount] (let [token-‐req (auth/card-‐token user-‐id) details-‐req (bill/details bill-‐id)] (do [token token-‐req transaction (payment/bill bill-‐id amount token) details details-‐req] (return (if (success? transaction) (render-‐remaining-‐response details amount) error-‐response)))))
- 9. SOLUTION 1.1: PROMISE MONAD LET/DO/DO (GET "/bills/:bill-‐id/payments" [bill-‐id user-‐id amount] (let [token-‐req (auth/card-‐token user-‐id) details-‐req (bill/details bill-‐id)] (do [token token-‐req transaction (payment/bill bill-‐id amount token)] (if (success? transaction) (do [details details-‐req] (return (render-‐remaining-‐response details amount))) (return error-‐response)))))
- 10. SOLUTION 1.2: PROMISE MONAD DO (GET "/bills/:bill-‐id/payments" [bill-‐id user-‐id amount] (do [token (auth/card-‐token user-‐id) transaction (payment/bill bill-‐id amount token) details (bill/details bill-‐id)] (return (if (success? transaction) (render-‐remaining-‐response details amount) error-‐response))))
- 11. SOLUTION 1.3: PROMISE + ERROR MONADS (GET "/bills/:bill-‐id/payments" [bill-‐id user-‐id amount] (do [token (auth/card-‐token user-‐id) transaction (payment/bill bill-‐id amount token) details (bill/details bill-‐id)] (return (render-‐remaining-‐response details amount))))
- 12. SOLUTION 2: PROMISE CHAIN AND LIFT-M-2 (GET "/bills/:bill-‐id/payments" [bill-‐id user-‐id amount] (let [transaction-‐req (chain (promise user-‐id) auth/card-‐token (partial payment/bill bill-‐id amount)) details-‐req (bill/details bill-‐id)] (lift-‐m-‐2 (fn [transaction details] (if (success? transaction) (render-‐remaining-‐response details amount) error-‐response))) transaction-‐req details-‐req))
- 13. SOLUTION 3: RAW PROMISES (GET "/bills/:bill-‐id/payments" [bill-‐id user-‐id amount] (let [transaction-‐req (-‐> (auth/card-‐token user-‐id) (then (partial payment/bill bill-‐id amount))) details-‐req (bill/details bill-‐id)] (when transaction-‐req details-‐req (fn [transaction details] (if (success? transaction) (render-‐remaining-‐response details amount) error-‐response)))))
- 14. SOLUTION 4: RAW CALLBACKS Not Viable
- 15. SOLUTION 5: CORE.ASYNC (GET "/bills/:bill-‐id/payments" [bill-‐id user-‐id amount] (go (let [token (auth/card-‐token user-‐id) details (bill/details bill-‐id) transaction (payment/bill bill-‐id amount (<! token))] (if (success? (<! transaction)) (render-‐remaining-‐response (<! details) amount) error-‐response))))
- 16. SOLUTION 6: LAMINA PIPELINE (GET "/bills/:bill-‐id/payments" [bill-‐id user-‐id amount] (let [details-‐req (bill/details bill-‐id)] (pipeline (auth/card-‐token user-‐id) (partial payment/bill bill-‐id amount) (fn [transaction] (if (success? transaction) (on-‐realized details-‐req (fn [details] (render-‐remaining-‐response details amount))) error-‐response)))))
- 18. SOLUTION 8: PULSAR PROMISES (GET "/bills/:bill-‐id/payments" [bill-‐id user-‐id amount] #(let [token (auth-‐card-‐token user-‐id) details (bill-‐details bill-‐id) transaction (payment-‐bill bill-‐id amount @token)] (if (success? @transaction) (render-‐remaining-‐response @details amount) error-‐response)))
- 19. SOLUTION 9: PULSAR ACTORS Not Appropriate
- 20. (GET "/bills/:bill-‐id/payments" [bill-‐id user-‐id amount] (let [token (auth/card-‐token user-‐id) details (bill/details bill-‐id) transaction (payment/bill bill-‐id amount @token)] (if (success? @transaction) (render-‐remaining-‐response @details amount) error-‐response))) Synchronous (GET "/bills/:bill-‐id/payments" [bill-‐id user-‐id amount] (go (let [token (auth/card-‐token user-‐id) details (bill/details bill-‐id) transaction (payment/bill bill-‐id amount (<! token))] (if (success? (<! transaction)) (render-‐remaining-‐response (<! details) amount) error-‐response)))) core.async (GET "/bills/:bill-‐id/payments" [bill-‐id user-‐id amount] #(let [token (auth-‐card-‐token user-‐id) details (bill-‐details bill-‐id) transaction (payment-‐bill bill-‐id amount @token)] (if (success? @transaction) (render-‐remaining-‐response @details amount) (error-‐response)))) Pulsar
- 21. SCALA def payBill(billId: Integer, userId: Integer, amount: Integer):Future[Option[Json]] = { val seq = for { token <-‐ Auth.cardToken(userId) tr <-‐ Payment.bill(token) } yield tr async { val transactionProcess = await(seq.run) val detailProcess = await(BillOps.details(billId)) for { transaction <-‐ transactionProcess detail <-‐ detailProcess } yield renderRemainingResponse(amount, detail) } }
- 23. HELLO WORLD • Single C1-Medium • 7GB •8 Ram Cores • 313,852 Concurrent Users • 4756.79 Requests Per Second • More meaningful results once in SVT with full implementation
- 24. ALL DONE AT AUSTRALIA POST DIGITAL MAILBOX They're hiring. Send your CV to APDMRecruitment@auspost.com.au