Issue #9115 has been updated by Bill Paulson. The source code for 2.1.2 doesn't seem to have changed: the LogDevice::write method still does a rescue Exception and ignores the result. Our application ran into this problem when one thread raises an exception in another thread that's doing a LogDevice::write(). The exception is supposed to be handled at a higher level, so write() rescuing it and ignoring it causes our application to hang. A write() method without this problem looks like ~~~ def write(message) @mutex.synchronize do if @shift_age and @dev.respond_to?(:stat) begin check_shift_log rescue IOError warn("log shifting failed. #{$!}") end end begin @dev.write(message) rescue IOError warn("log writing failed. #{$!}") end end end ~~~ ---------------------------------------- Bug #9115: Logger traps all exceptions; breaks Timeout https://bugs.ruby-lang.org/issues/9115#change-48642 * Author: Chris Phoenix * Status: Open * Priority: Normal * Assignee: * Category: * Target version: * ruby -v: ruby 2.0.0p247 (2013-06-27) [i386-mingw32] * Backport: 1.9.3: UNKNOWN, 2.0.0: UNKNOWN ---------------------------------------- Line 577-579 of logger.rb rescue Exception => ignored warn("log writing failed. #{ignored}") end Thus, when the system times out in the middle of writing a log message, it warns "log writing failed. execution expired" and just keeps right on running. This is true in 1.9.3 as well. I haven't looked at older versions. Pardon me while I go grep "rescue Exception" in the entire Ruby codebase, and see whether I can reliably use Timeout at all... OK, you might check out C:\Ruby200\lib\ruby\gems\2.0.0\gems\activerecord-3.2.13\lib\active_record\railties\databases.rake All the other "rescue Exception" seem to re-raise it, except maybe C:\Ruby200\lib\ruby\2.0.0\xmlrpc\server.rb and C:\Ruby200\lib\ruby\gems\2.0.0\gems\activesupport-3.2.13\lib\active_support\callbacks.rb -- https://bugs.ruby-lang.org/