Bug #5618


Exceptions cause DRb connection to be closed

Added by larsch (Lars Christensen) over 11 years ago. Updated over 3 years ago.

Target version:
ruby -v:
ruby 1.9.3p0 (2011-10-30) [i386-mingw32]


If an exception is thrown in a DRb server of a class that is not defined in the client process, the DRb connection is closed abrubtly. In Ruby 1.8, the exception was translated to an instance generic exception class (DRb::DRbRemoteError).

Steps to reproduce:

  1. Start DRb client+server
  2. Throw exception of custom class in server (class not defined in client script).

Observed behaviour:

  1. Client raises DRb::DRbConnError because connection is closed - used to be generic error.

Expected behaviour:

  1. Client raises DRb::DRbRemoteError, and preserves full stack trace from server.

Attached is server/client script showing the problem.

Here is the stack trace of the client:

C:/lang/Ruby193/lib/ruby/1.9.1/drb/drb.rb:570:in load': connection closed (DRb::DRbConnError) from C:/lang/Ruby193/lib/ruby/1.9.1/drb/drb.rb:632:in recv_reply'
from C:/lang/Ruby193/lib/ruby/1.9.1/drb/drb.rb:918:in recv_reply' from C:/lang/Ruby193/lib/ruby/1.9.1/drb/drb.rb:1197:in send_message'
from C:/lang/Ruby193/lib/ruby/1.9.1/drb/drb.rb:1088:in block (2 levels) in method_missing' from C:/lang/Ruby193/lib/ruby/1.9.1/drb/drb.rb:1172:in open'
from C:/lang/Ruby193/lib/ruby/1.9.1/drb/drb.rb:1087:in block in method_missing' from C:/lang/Ruby193/lib/ruby/1.9.1/drb/drb.rb:1105:in with_friend'
from C:/lang/Ruby193/lib/ruby/1.9.1/drb/drb.rb:1086:in method_missing' from drbclient.rb:3:in '


drbserver.rb (194 Bytes) drbserver.rb DRb Server larsch (Lars Christensen), 11/11/2011 10:49 PM
drbclient.rb (75 Bytes) drbclient.rb DRb Client larsch (Lars Christensen), 11/11/2011 10:49 PM
drb-rescue-exception-5618.patch (1.03 KB) drb-rescue-exception-5618.patch jeremyevans0 (Jeremy Evans), 08/14/2019 11:52 PM

Updated by ko1 (Koichi Sasada) about 11 years ago

  • Category set to lib
  • Assignee set to seki (Masatoshi Seki)
Actions #2

Updated by shyouhei (Shyouhei Urabe) about 11 years ago

  • Status changed from Open to Assigned

Updated by felixbuenemann (Felix B√ľnemann) about 8 years ago

This issue still exists in Ruby 2.1.5.

Updated by jeremyevans0 (Jeremy Evans) over 3 years ago

This issue is unrelated to whether the client defines the same exception class as the server, and the behavior in my testing appears to be the same on 1.8 as in the master branch.

The underlying issue is that the example code here uses a subclass of Exception, and DRb::DRbServer::InvokeMethod#perform does not rescue Exception. Attached is a patch that fixes this issue.

Actions #5

Updated by jeremyevans (Jeremy Evans) over 3 years ago

  • Status changed from Assigned to Closed

Applied in changeset git|50b8033d6b7404670ee985de1473fffc10dd7d9c.

Handle subclasses of Exception in drb

This makes it so that client instances that call a method on a
server-side object that raise a subclass of Exception are handled
similarly to those that raise a subclass of StandardError.

Only reraise exceptions that we are fairly sure we don't want to

Fixes [Bug #5618]


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