From: ptkwt@...1.aracnet.com (Phil Tomson)
Date: 2002-03-22T04:26:21+09:00
Subject: Re: drb weirdness

In article <3c9a1eb6_1@news7.fast.net>,  <juergen@fiedlerfamily.net> wrote:
>Hello,
>
>I am using drb-1.3.4 with ruby-1.6.6 and I am trying to get the
>examples from 'Programming Ruby' to run.
>I have a server that looks like this:
>
>---
>#! /usr/bin/ruby -w
>
>require 'drb'
>
>class TestServer
>  def doit
>    "Hello, Distributed World"
>  end
>end
>
>aServerObject = TestServer.new
>DRb.start_service('druby://cavemaus.fiedlerfamily.net:15986', aServerObject)
>DRb.thread.join
>---
>
>and a client that looks like this:
>
>---
>#! /usr/bin/ruby -w
>
>require 'drb'
>
>DRb.start_service()
>obj = DRbObject.new(nil, 'druby://cavemaus.fiedlerfamily.net:15986')
>p obj.doit
>---
>
>The server starts OK and running the client produces the expected
>output. But every time the 'p obj.doit' line of the client executes,
>the server prints the following error message:
>
>---
>#<TypeError: invalid header>
>/usr/lib/ruby/1.6/drb/drb.rb:118:in `load'
>/usr/lib/ruby/1.6/drb/drb.rb:143:in `recv_request'
>/usr/lib/ruby/1.6/drb/drb.rb:447:in `proc'
>/usr/lib/ruby/1.6/drb/drb.rb:488:in `loop'
>/usr/lib/ruby/1.6/drb/drb.rb:488:in `proc'
>/usr/lib/ruby/1.6/drb/drb.rb:439:in `start'
>/usr/lib/ruby/1.6/drb/drb.rb:439:in `proc'
>/usr/lib/ruby/1.6/drb/drb.rb:408:in `run'
>/usr/lib/ruby/1.6/drb/drb.rb:405:in `start'
>/usr/lib/ruby/1.6/drb/drb.rb:405:in `run'
>/usr/lib/ruby/1.6/drb/drb.rb:367:in `initialize'
>/usr/lib/ruby/1.6/drb/drb.rb:497:in `new'
>/usr/lib/ruby/1.6/drb/drb.rb:497:in `start_service'
>./server.rb:12
>---
>
>Line 12 is the start_service call.
>Does anybody know what that means and how I can get rid of this message?

Are you running the same version of Ruby on both client and server? (you 
should be)
Are you running the same version of drb on both client and server? (again, 
you should be)
What platform are you running these on?

This is just a warning, right? (the server and client keep running?)

>While I'm at it, is there any drb documentation besides the reference
>manual that is not in Japanese?

There is a section in the book "The Ruby Way" that covers drb.

There is also a DRb tutorial at:

http://www.chadfowler.com/ruby/drb.html

Phil