3 ms·

I think you meant to say sub 20 second start times for clojure apps :) But seriously completely agree with you about the jvm being awesome. However clojure var

I think you meant to say sub 20 second start times for clojure apps :) But seriously completely agree with you about the jvm being awesome. However clojure var load times on top of the base jvm and memory use makes it dog slow to start a development repl(30+ seconds is normal.. queue comment about how someone only restarts their repl every couple of days LOL) and unsuitable or unusable for situations where you care about app start times of less than 10 seconds and memory constrained environments such as cli, iot, serverless, android.

swlkr 9y ago
My repl starts in about a second... maybe it’s because I’m using cursive
- hellofunk 9y ago
  Whatever your setup, there is no way you are starting a JVM from scratch and then loading a Clojure REPL in one second. I promise you that is not happening.
  - pjmlp 9y ago
    Blame Clojure's implementation. The (Clojure) "JVM Slow Startup Time" Myth http://blog.ndk.io/jvm-slow-startup.html http://blog.ndk.io/jvm-slow-startup.html
  - SevereOverfl0w 9y ago
    Have you tried the new clj command line tool from Clojure themselves? $ time clj -e '(System/exit 0)' clj -e '(System/exit 0)' 1.60s user 0.07s system 198% cpu 0.839 total It takes about 2 seconds to start for me. In this case I suspect cursive is fast because: * You have a JVM loaded in the form of IntelliJ * You only need to start Clojure inside that JVM (which is reduced from the time clj takes!) So 1 second is a reasonable time from IntelliJ=>Clojure. 2 seconds is reasonable for Nothing=>Clojure.
    - cutler 9y ago
      I'm lost. I have Java 9 and the latest Clojure 1.9 plus Leiningen. No 'clj' in my PATH. Where does this new command live?
      - grzm 9y ago
        See the getting started guide on how to install the CLI. https://clojure.org/guides/getting_started https://clojure.org/guides/getting_started
    - didibus 9y ago
      Its not 2 seconds. With the time command, you have to look at the elapsed time. Clojure does parallel execution, that's why you see CPU at 198%. So the user and sys time are the sum of the time on each cores. So the actual time was 0.839s. Which means Clojure 1.9 on your computer boots and shutdowns its repl in under a second.

swlkr 9y ago

My repl starts in about a second... maybe it’s because I’m using cursive

hellofunk 9y ago
Whatever your setup, there is no way you are starting a JVM from scratch and then loading a Clojure REPL in one second. I promise you that is not happening.
- pjmlp 9y ago
  Blame Clojure's implementation. The (Clojure) "JVM Slow Startup Time" Myth http://blog.ndk.io/jvm-slow-startup.html http://blog.ndk.io/jvm-slow-startup.html
- SevereOverfl0w 9y ago
  Have you tried the new clj command line tool from Clojure themselves? $ time clj -e '(System/exit 0)' clj -e '(System/exit 0)' 1.60s user 0.07s system 198% cpu 0.839 total It takes about 2 seconds to start for me. In this case I suspect cursive is fast because: * You have a JVM loaded in the form of IntelliJ * You only need to start Clojure inside that JVM (which is reduced from the time clj takes!) So 1 second is a reasonable time from IntelliJ=>Clojure. 2 seconds is reasonable for Nothing=>Clojure.
  - cutler 9y ago
    I'm lost. I have Java 9 and the latest Clojure 1.9 plus Leiningen. No 'clj' in my PATH. Where does this new command live?
    - grzm 9y ago
      See the getting started guide on how to install the CLI. https://clojure.org/guides/getting_started https://clojure.org/guides/getting_started
  - didibus 9y ago
    Its not 2 seconds. With the time command, you have to look at the elapsed time. Clojure does parallel execution, that's why you see CPU at 198%. So the user and sys time are the sum of the time on each cores. So the actual time was 0.839s. Which means Clojure 1.9 on your computer boots and shutdowns its repl in under a second.