Merge branch 'master' of github.com:lifo/docrails

Conflicts:
	activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

1 files changed, 11 insertions, 0 deletions

diff --git a/guides/source/debugging_rails_applications.textile b/guides/source/debugging_rails_applications.textile
index 667f2d2140..a5a22a8a8f 100644
--- a/guides/source/debugging_rails_applications.textile
+++ b/guides/source/debugging_rails_applications.textile
@@ -191,6 +191,17 @@ Completed in 0.01224 (81 reqs/sec) | DB: 0.00044 (3%) | 302 Found [http://localh
 
 Adding extra logging like this makes it easy to search for unexpected or unusual behavior in your logs. If you add extra logging, be sure to make sensible use of log levels, to avoid filling your production logs with useless trivia.
 
+h4. Tagged Logging
+
+When running multi-user, multi-account applications, it’s often useful to be able to filter the logs using some custom rules. +TaggedLogging+ in Active Support helps in doing exactly that by stamping log lines with subdomains, request ids, and anything else to aid debugging such applications.
+
+<ruby>
+logger = ActiveSupport::TaggedLogging.new(Logger.new(STDOUT))
+logger.tagged("BCX") { logger.info "Stuff" }                            # Logs "[BCX] Stuff"
+logger.tagged("BCX", "Jason") { logger.info "Stuff" }                   # Logs "[BCX] [Jason] Stuff"
+logger.tagged("BCX") { logger.tagged("Jason") { logger.info "Stuff" } } # Logs "[BCX] [Jason] Stuff"
+</ruby>
+
 h3. Debugging with the +debugger+ gem
 
 When your code is behaving in unexpected ways, you can try printing to logs or the console to diagnose the problem. Unfortunately, there are times when this sort of error tracking is not effective in finding the root cause of a problem. When you actually need to journey into your running source code, the debugger is your best companion.