Are you using jdk7u40? JRuby 1.7.4 enables InvokeDynamic by default if you're using jdk7u40 (or newer), which came with a new InvokeDynamic implementation that can require a lot more memory (e.g. 2-3 times more loaded classes). JRuby 1.7.5 disables InvokeDynamic by default on Java 7, partly because of this.

Anyway, if this is true, try upgrading to 1.7.5 or disabling InvokeDynamic manually by setting the property "jruby.compile.invokedynamic" to "false".

Thanks for your quick responding. We are using jdk "1.7.0_25", and also tried disable InvokeDynamic and upgrade to 1.7.5. But seems not get much improvement. Almost 50% more memory used.

And also more CPU is consumed after the upgrade.

1.7.0_25 should not enable invokedynamic in any case, so there's some other issue.

I would not expect JRuby 1.7 to use significantly more memory or CPU than 1.6. And it should actually run faster and more efficiently than 1.6. I think we need more information about your app and your usage of ScriptContext.

simply put, the usage is like following:

ScriptEngineManager sem = new ScriptEngineManager();
ScriptEngine engineByName = sem.getEngineByName("jruby");
SimpleScriptContext context = new SimpleScriptContext();
//set several shared instance to the context
context.setAttribute("appInstance", this, ScriptContext.ENGINE_SCOPE);
//in the script we will invoke methods on the instance passed in by script context
CompiledScript compile = ((Compilable) engineByName).compile(script);
compile.eval(context);

And in our real application, the script is gotten via HTTP.

closing as this is no longer relevant :)