diff --git a/services/document-updater/app/coffee/RealTimeRedisManager.coffee b/services/document-updater/app/coffee/RealTimeRedisManager.coffee
index 6fd48033da..775132f1b6 100644
--- a/services/document-updater/app/coffee/RealTimeRedisManager.coffee
+++ b/services/document-updater/app/coffee/RealTimeRedisManager.coffee
@@ -39,9 +39,13 @@ module.exports = RealTimeRedisManager =
 		# create a unique message id using a counter
 		message_id = "doc:#{HOST}:#{RND}-#{COUNT++}"
 		data?._id = message_id
+
+		blob = JSON.stringify(data)
+		metrics.summary "redis.publish.applied-ops", blob.length
+
 		# publish on separate channels for individual projects and docs when
 		# configured (needs realtime to be configured for this too).
 		if Settings.publishOnIndividualChannels
-			pubsubClient.publish "applied-ops:#{data.doc_id}", JSON.stringify(data)
+			pubsubClient.publish "applied-ops:#{data.doc_id}", blob
 		else
-			pubsubClient.publish "applied-ops", JSON.stringify(data)
+			pubsubClient.publish "applied-ops", blob
diff --git a/services/document-updater/test/unit/coffee/RealTimeRedisManager/RealTimeRedisManagerTests.coffee b/services/document-updater/test/unit/coffee/RealTimeRedisManager/RealTimeRedisManagerTests.coffee
index 13e532736e..429a03b971 100644
--- a/services/document-updater/test/unit/coffee/RealTimeRedisManager/RealTimeRedisManagerTests.coffee
+++ b/services/document-updater/test/unit/coffee/RealTimeRedisManager/RealTimeRedisManagerTests.coffee
@@ -90,3 +90,6 @@ describe "RealTimeRedisManager", ->
 
 		it "should send the op with a message id", ->
 			@pubsubClient.publish.calledWith("applied-ops", JSON.stringify({op:"thisop",_id:@message_id})).should.equal true
+
+		it "should track the payload size", ->
+			@metrics.summary.calledWith("redis.publish.applied-ops", JSON.stringify({op:"thisop",_id:@message_id}).length).should.equal true