Apache Camel is the swiss army knife of application integration. If your application is processing data from different systems, sooner or later you will end up using some of the 130 (and growing number of) connectors available. Camel also has excellent cloud support. You can use either jCoulds component that provides portable service abstraction layer for Amazon, GoGrid, VMWare, Azure, and Rackspace or use Amazon specific components for SQS, SNS, S3, SES, SDB, DDB (some of which contributed by me).
In this tutorial I'm going to show you how to monitor Camel applications with JMX and Amazon CloudWatch service. The need for such a monitoring arose after I created livephotostream - the photo streaming application I created while playing with Camel. This application retrieves real time photos from Twitter streaming api, and not so real time data from Instagram and Tumblr, then display them using Bootstrap and sometimes Websocket. And I wanted to see how many photos it is receiving, how many of them are failing, how long it takes to process a photo and so on. So I end up creating a camel-cloudwatch component and a simple application demonstrating how to use it to display JMX metrics.
This is when the new cloudwatch producer becomes useful. It lets you send custom metrics to amazon CloudWatch service. All you have to do is give a namespace to your metrics, and send each metric by specifying its name, value and optionally the unit and timestamp. If you don't specify the unit and timestamp it will use count as unit and the current time as the metric time.
The route above doesn't require any additional code. It will send any changes to the ExchangesFailed attribute to CloudWatch service, and you can see the error count not changing in the CloudWatch graph:
In this scenario you will need also a timer to trigger the polling. The cloudwatch producer can generate a metric based on message headers as in the first example, or simply send the metric objects from the message body if present as in the second example. The processor for retrieving data from camel jmx is also straightforward and can be seen in the demo app on my guthub account.
The result from the last route is couple of metrics, all of which sent to CloudWatch every minute. As you can see from the next image the number of exchanges completed successfully is increasing all the time, but with a different rate: