[javaispoo]

Might be quick when running but the jvm startup time is a pain. By the time the java solution starts up, my c based solution has already finished.

[sarnowski]

http://blog.ndk.io/2014/02/11/jvm-slow-startup.html

40ms sounds okay for me, even for most command line tools. Oh and I most probably don't get a segmentation fault ;-)

[juliangregorian]

Sure wish my JVM started in 40ms. Here's ruby:

    $ time ruby -e "puts 'hello world'"
    > hello world
    >
    > real	0m0.076s
    > user	0m0.029s
    > sys	0m0.017s

And here's jruby:

    $ time ruby -e "puts 'hello world'"
    > hello world
    >
    > real	0m1.161s
    > user	0m2.050s
    > sys	0m0.093s

[ssmoot]

Your JVM does. jruby.jar is megabytes of reimplementation and mapping of the Ruby stdlib onto the JVM. Plus in this example, loading a Ruby parser and interpreter.

Here's executing an assembly (über-jar) I wrote in Scala:

  → time scripts/couch 
  Please provide a basePath and a valid command. ("backup", "restore", "truncate", "migrate" or "migrate-all")

  real	0m0.375s
  user	0m0.415s
  sys	0m0.073s

That's basically just `java -jar couch-utils.jar`.

A few hundred ms on my 1.2GHz MacBook. And this includes a bunch of Akka Actors.

[pjc50]

That rather proves the opposite: 6s Clojure startup time, for reasons that aren't obvious enough to be included in that blog post.

[sarnowski]

But its neither a Java nor JVM problem.

[tlammens]

Startup time in a server is a non-issue... Those processes keep running the whole time.

[javaispoo]

Yeah, and memory is infinite, and all disks are free, and the computing fairies make all the processors super fast. But back in the real world, startup time is a valid concern.

[sarnowski]

Don't know your "real" world. In my real world, the AWS instance takes several minutes to come up - I can spare some milliseconds on thr JVM startup.

[vidarh]

In my real world the containers we spin up come up in seconds, but container restart is far more rare than restarting services.

[thescrewdriver]

If the time to restart your process or host affects the overall operation and performance of your service you're doing it wrong.

[vidarh]

If your services consistently restart quickly, it gives you the freedom to design things differently.

E.g. doing a rolling update across a large number of instances by restarting a service at a time can become a quick enough process to be viable in instances where you'd otherwise need lots of excess capacity to be able to cycle larger proportions of instances at the same time. Making full rolling updates "cheaper" both in time and resources also translates to making rapid updates a safer choice (e.g. if I can roll back a broken release in 5 minutes, it's far safer to push out a new release than if a rollback takes hours).

[astrange]

That just means you expect restarting to be slow and have excluded it from your system design.

There is no problem with restarting nginx to update its config once a second, and it's even encouraged that you do so. Besides, crash-only software recovery is really the only morally sound development technique.

[Twirrim]

What are you doing that you frequently starts / shuts down an application to the order where 70ms is a problem?

[eterm]

Not just frequently starting/stopping applications but a persistence engine at that.

[astrodust]

How many reboots per second are you having to endure? Maybe you should make your server process crash less often.