diff --git a/lib/logstash/outputs/mongodb.rb b/lib/logstash/outputs/mongodb.rb
index d53ddd866..43183ba51 100644
--- a/lib/logstash/outputs/mongodb.rb
+++ b/lib/logstash/outputs/mongodb.rb
@@ -6,18 +6,13 @@ class LogStash::Outputs::Mongodb < LogStash::Outputs::Base
   config_name "mongodb"
   plugin_status "beta"
 
-  # your mongodb host
-  config :host, :validate => :string, :required => true
-
-  # the mongodb port
-  config :port, :validate => :number, :default => 27017
-
+  # a MongoDB URI to connect to
+  # See http://docs.mongodb.org/manual/reference/connection-string/
+  config :uri, :validate => :string, :required => true
+  
   # The database to use
   config :database, :validate => :string, :required => true
-
-  config :user, :validate => :string, :required => false
-  config :password, :validate => :password, :required => false
-
+   
   # The collection to use. This value can use %{foo} values to dynamically
   # select a collection based on data in the event.
   config :collection, :validate => :string, :required => true
@@ -30,19 +25,23 @@ class LogStash::Outputs::Mongodb < LogStash::Outputs::Base
   # Number of seconds to wait after failure before retrying
   config :retry_delay, :validate => :number, :default => 3, :required => false
 
+  # If true, a _id field will be added to the document before insertion.
+  # The _id field will use the timestamp of the event and overwrite an existing
+  # _id field in the event.
+  config :generateId, :validate => :boolean, :default => false
+
   public
   def register
     require "mongo"
-    # TODO(petef): check for errors
-    db = Mongo::Connection.new(@host, @port).db(@database)
-    auth = true
-    if @user then
-      auth = db.authenticate(@user, @password.value) if @user
+    uriParsed=Mongo::URIParser.new(@uri)
+    conn = uriParsed.connection({})
+    if uriParsed.auths.length > 0
+      uriParsed.auths.each do |auth|
+        conn.add_auth(auth['db_name'], auth['username'], auth['password'])
+      end
+      conn.apply_saved_authentication()
     end
-    if not auth then
-      raise RuntimeError, "MongoDB authentication failure"
-    end
-    @mongodb = db
+    @db = conn.db(@database)
   end # def register
 
   public
@@ -54,15 +53,26 @@ class LogStash::Outputs::Mongodb < LogStash::Outputs::Base
         # the mongodb driver wants time values as a ruby Time object.
         # set the @timestamp value of the document to a ruby Time object, then.
         document = event.to_hash.merge("@timestamp" => event.ruby_timestamp)
-        @mongodb.collection(event.sprintf(@collection)).insert(document)
       else
-        @mongodb.collection(event.sprintf(@collection)).insert(event.to_hash)
+        document = event.to_hash
       end
+      if @generateId
+        document['_id'] = BSON::ObjectId.new(nil, event.ruby_timestamp)
+      end
+      @db.collection(event.sprintf(@collection)).insert(document)
     rescue => e
       @logger.warn("Failed to send event to MongoDB", :event => event, :exception => e,
                    :backtrace => e.backtrace)
-      sleep @retry_delay
-      retry
+      if e.error_code == 11000
+          # On a duplicate key error, skip the insert.
+          # We could check if the duplicate key err is the _id key
+          # and generate a new primary key.
+          # If the duplicate key error is on another field, we have no way
+          # to fix the issue.
+      else
+        sleep @retry_delay
+        retry
+      end
     end
   end # def receive
 end # class LogStash::Outputs::Mongodb