diff --git a/lib/logstash/filters/multiline.rb b/lib/logstash/filters/multiline.rb
index 4b9b10c74..a26b21534 100644
--- a/lib/logstash/filters/multiline.rb
+++ b/lib/logstash/filters/multiline.rb
@@ -14,7 +14,6 @@ require "set"
 # from files into a single event. For example - joining java exception and
 # stacktrace messages into a single event.
 #
-# TODO(sissel): Document any issues?
 # The config looks like this:
 #
 #     filter {
@@ -67,6 +66,9 @@ class LogStash::Filters::Multiline < LogStash::Filters::Base
   # The regular expression to match
   config :pattern, :validate => :string, :required => true
 
+  # The field to use for matching
+  config :source, :validate => :string, :default => "message"
+
   # If the pattern matched, does event belong to the next or previous event?
   config :what, :validate => ["previous", "next"], :required => true
 
@@ -84,8 +86,8 @@ class LogStash::Filters::Multiline < LogStash::Filters::Base
   # reconnects (due to error or client restart), then logstash will identify
   # the new connection as a new stream and break any multiline goodness that
   # may have occurred between the old and new connection. To solve this use
-  # case, you can use "%{@source_host}.%{@type}" instead.
-  config :stream_identity , :validate => :string, :default => "%{@source}.%{@type}"
+  # case, you can use "%{host}.%{type}" instead.
+  config :stream_identity , :validate => :string, :default => "%{host}-%{path}-%{type}"
   
   # logstash ships by default with a bunch of patterns, so you don't
   # necessarily need to define this yourself unless you are adding additional
@@ -100,6 +102,13 @@ class LogStash::Filters::Multiline < LogStash::Filters::Base
   #     NUMBER \d+
   config :patterns_dir, :validate => :array, :default => []
 
+  # Flush inactive multiline streams older than the given number of
+  # seconds.
+  #
+  # This is useful when your event stream is slow and you do not want to wait
+  # for the next event before seeing the current event.
+  #config :flush_age, :validate => :number, :default => 5
+
   # Detect if we are running from a jarfile, pick the right path.
   @@patterns_path = Set.new
   if __FILE__ =~ /file:\/.*\.jar!.*/
@@ -152,15 +161,15 @@ class LogStash::Filters::Multiline < LogStash::Filters::Base
   def filter(event)
     return unless filter?(event)
 
-    if event.message.is_a?(Array)
-      match = @grok.match(event.message.first)
+    if event[@source].is_a?(Array)
+      match = @grok.match(event[@source].first)
     else
-      match = @grok.match(event.message)
+      match = @grok.match(event[@source])
     end
     key = event.sprintf(@stream_identity)
     pending = @pending[key]
 
-    @logger.debug("Multiline", :pattern => @pattern, :message => event.message,
+    @logger.debug("Multiline", :pattern => @pattern, :message => event["message"],
                   :match => match, :negate => @negate)
 
     # Add negate option
@@ -169,7 +178,7 @@ class LogStash::Filters::Multiline < LogStash::Filters::Base
     case @what
     when "previous"
       if match
-        event.tags |= ["multiline"]
+        event.tag("multiline")
         # previous previous line is part of this event.
         # append it to the event and cancel it
         if pending
@@ -183,17 +192,16 @@ class LogStash::Filters::Multiline < LogStash::Filters::Base
         # if we have a pending event, it's done, send it.
         # put the current event into pending
         if pending
-          tmp = event.to_hash
-          event.overwrite(pending)
-          @pending[key] = LogStash::Event.new(tmp)
-        else
-          @pending[key] = event
-          event.cancel
-        end # if/else pending
+          pending.uncancel
+          pending[@source] = pending[@source].join("\n") if pending[@source].is_a?(Array)
+          yield pending
+        end
+        @pending[key] = event
+        event.cancel
       end # if/else match
     when "next"
       if match
-        event.tags |= ["multiline"]
+        event.tag("multiline")
         # this line is part of a multiline event, the next
         # line will be part, too, put it into pending.
         if pending
@@ -208,8 +216,9 @@ class LogStash::Filters::Multiline < LogStash::Filters::Base
         # multiline, send it.
         if pending
           pending.append(event)
-          event.overwrite(pending.to_hash)
           @pending.delete(key)
+          pending[@source] = pending[@source].join("\n") if pending[@source].is_a?(Array)
+          yield pending
         end
       end # if/else match
     else
@@ -218,18 +227,23 @@ class LogStash::Filters::Multiline < LogStash::Filters::Base
     end # case @what
 
     if !event.cancelled?
+      event[@source] = event[@source].join("\n") if event[@source].is_a?(Array)
       filter_matched(event)
     end
   end # def filter
 
-  # Flush any pending messages. This is generally used for unit testing only.
   public
   def flush
     events = []
-    @pending.each do |key, value|
-      value.uncancel
-      events << value
+    #flushed = []
+    @pending.each do |key, event|
+      #next unless @flush_age.nil? || (Time.now - event.timestamp) > @flush_age
+      event.uncancel
+      event[@source] = event[@source].join("\n") if event[@source].is_a?(Array)
+      events << event
+      #flushed << key
     end
+    #flushed.each { |k| @pending.delete(k) }
     @pending.clear
     return events
   end # def flush
diff --git a/spec/filters/multiline.rb b/spec/filters/multiline.rb
index 4781c1cf4..aa74c0851 100644
--- a/spec/filters/multiline.rb
+++ b/spec/filters/multiline.rb
@@ -16,8 +16,8 @@ describe LogStash::Filters::Multiline do
 
     sample [ "hello world", "   second line", "another first line" ] do
       insist { subject.length } == 2
-      insist { subject[0].message } == "hello world\n   second line"
-      insist { subject[1].message } == "another first line"
+      insist { subject[0]["message"] } == "hello world\n   second line"
+      insist { subject[1]["message"] } == "another first line"
     end
   end
 
@@ -33,8 +33,8 @@ describe LogStash::Filters::Multiline do
     CONFIG
 
     sample [ "120913 12:04:33 first line", "second line", "third line" ] do
-      reject { subject}.is_a? Array
-      insist { subject.message } ==  "120913 12:04:33 first line\nsecond line\nthird line"
+      reject { subject }.is_a? Array
+      insist { subject["message"] } ==  "120913 12:04:33 first line\nsecond line\nthird line"
     end
   end
 
@@ -61,9 +61,7 @@ describe LogStash::Filters::Multiline do
         [ "hello world #{stream}" ] \
         + rand(5).times.collect { |n| id += 1; "   extra line #{n} in #{stream} event #{id}" }
       ) .collect do |line|
-        LogStash::Event.new("@message" => line,
-                            "@source" => stream, "@type" => stream,
-                            "@fields" => { "event" => i })
+        { "message" => line, "source" => stream, "type" => stream, "event" => i }
       end
     end
 
@@ -77,7 +75,7 @@ describe LogStash::Filters::Multiline do
       index = rand(eventstream.count)
       event = eventstream[index].shift
       eventstream.delete_at(index) if eventstream[index].empty?
-      event
+      next event
     end
 
     sample concurrent_stream do 
@@ -86,7 +84,7 @@ describe LogStash::Filters::Multiline do
         #puts "#{i}/#{event["event"]}: #{event.to_json}"
         #insist { event.type } == stream
         #insist { event.source } == stream
-        insist { event.message.split("\n").first } =~ /hello world /
+        insist { event["message"].split("\n").first } =~ /hello world /
       end
     end
   end
diff --git a/spec/test_utils.rb b/spec/test_utils.rb
index b4352dd0c..220bf2a94 100644
--- a/spec/test_utils.rb
+++ b/spec/test_utils.rb
@@ -69,11 +69,12 @@ module LogStash
           end
           
           results = []
+          count = 0
           event.each do |e|
             filters.each do |filter|
               next if e.cancelled?
               filter.filter(e) do |newevent|
-                event << newevent
+                results << newevent unless e.cancelled?
               end
             end
             results << e unless e.cancelled?