JRuby slowdown from Rails 2.0.2 to 2.1.0

Before you decide to bring your current JRuby on Rails app to the latest 2.1.0 version… you may want to take a look at the performance. I was running the console benchmark from this blog post with jruby trunk and saw some numbers I wasn’t expecting:


in console: 6.times {puts Benchmark.measure {10000.times {Person.find :first}}.total}
4.47 : jruby 1.1.2 & rails 2.0.2 (jdbc)  (best out of 6 runs)
5.43 : jruby 1.1.2 & rails 2.1.0 (jdbc)
4.12 : jruby 1.1.3 (trunk) & rails 2.0.2 (jdbc)
5.06 : jruby 1.1.3 (trunk) & rails 2.1.0 (jdbc)

JRuby trunk IS faster than 1.1.2 as expected, but JRuby overall is experiencing a (pretty significant) slowdown when running Rails 2.1.0.

Hopefully finding the culprit for this slowdown will open the floodgates for improving JRuby on Rails performance.

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8 Responses to “JRuby slowdown from Rails 2.0.2 to 2.1.0”

  1. And the MRI numbers of the same benchmark?

    Christian Seiler said this on July 4th, 2008 at 3:29 am

  2. I don’t actually see much of a difference, in both JRuby and Ruby, the newer rails/activerecord is slower by 10% or so.

    So, JRuby is getting faster (and the trunk is faster than released version 1.1.2), but newer activerecord is a bit slower with both JRuby and MRI, and I’m not sure why.

    Vladimir Sizikov said this on July 4th, 2008 at 3:41 am

  3. @Christian Seller : ruby 1.8.6 for both Rails 2.0.2 and 2.1.0 were about 5.06 so there was no noticeable slowdown there

    Mike McKinney said this on July 4th, 2008 at 9:32 am

  4. @Vladimir : interesting you saw no difference…

    Mike McKinney said this on July 4th, 2008 at 9:35 am

  5. Oh, with my setup things are even worse for JRuby.
    Setup: JRuby 1.1.2 / Ubuntu / latst JDK6 / activerecord-jdbc-adapter 0.8.1

    RAILS 2.1
    5.95 jdk6 -J-server
    2.68 MRI

    RAILS 2.0
    5.45 jdk6 -J-server
    3.1 MRI

    So Rails 2.1 is faster with MRI while it’s slower with JRuby.
    And JRuby/AR-JDBC is generally much slower than MRI.

    @Mike: Which OS are you on?

    Christian Seiler said this on July 4th, 2008 at 12:19 pm

  6. @Christian: Mac OS X (10.4) I have not had a chance to check things out on Linux yet.

    Mike McKinney said this on July 4th, 2008 at 4:35 pm

  7. latest JRuby trunk runs the test faster with Rails 2.1 than with 2.0:

    JRuby rev7134
    ————-
    Rails 2.0
    5.34 jruby -J-server -J-Xshare:off script/console
    5.30 jruby -X-C -J-server -J-Xshare:off script/console

    Rails 2.1
    5.39 jruby -J-server -J-Xshare:off script/console
    5.53 jruby -X-C -J-server -J-Xshare:off script/console

    rev7165
    ——-
    Rails 2.0
    5.27 jruby -J-server -J-Xshare:off script/console
    5.43 jruby -X-C -J-server -J-Xshare:off script/console
    5.21 jruby -J-server -J-Djruby.compile.fastest=true -J-Xshare:off script/console

    Rails 2.1
    5.23 jruby -J-server -J-Xshare:off script/console
    5.31 jruby -X-C -J-server -J-Xshare:off script/console
    5.18 jruby -J-server -J-Djruby.compile.fastest=true -J-Xshare:off script/console

    Christian Seiler said this on July 14th, 2008 at 1:32 pm

  8. I just found out that jirb turns on ObjectSpace which makes script/console pretty much useless for benchmarking. Numbers without ObjectSpace look much better:

    Rails 2.1
    3.82 jruby -J-server -J-Xshare:off script/console
    3.85 jruby -X-C -J-server -J-Xshare:off script/console
    3.75 jruby -J-server -J-Djruby.compile.fastest=true -J-Xshare:off script/console

    Christian Seiler said this on July 17th, 2008 at 2:00 am

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