This module provides an example of logging application events from a webapp to a Kite dataset via Flume (using log4j as the logging API) then querying the dataset using Hive JDBC.

To facilitate rapid development, the webapp runs a Hadoop minicluster that provides all the necessary components.

The example runs in a local Tomcat instance, as well as on Red Hat's OpenShift.

To build the project, type

git clone https://github.com/kite-sdk/kite-openshift-logging-example.git
cd kite-openshift-logging-example
mvn package

This creates a WAR file, which can be used in a Java EE 6 servlet container. For this example we'll start an embedded Tomcat instance using Maven:

mvn tomcat7:run

Navigate to http://localhost:8080/kite-openshift-logging-example, which presents you with a very simple web page for sending messages.

The message events are sent to the Flume agent over a socket, and the agent writes the events to the Kite dataset sink.

Send a few messages using the web form. Then wait 30 seconds for the sink to roll the file so that the data is visible. This page (which uses a Hive JDBC connection to run a query), shows all the events in the dataset: http://localhost:8080/kite-openshift-logging-example/all_events.jsp.

Before going any further you need to open an OpenShift account and install the client tools.

Note: You will need to have an account that allows you to run large gear sizes (this is not possible with the free account).

On your local machine run the following commands to create a new application called 'logging' running on OpenShift online:

rhc app create logging jbossews-2.0 -g large

This will create a plain webapp (its URL will be printed to the console). To replace it with the Kite webapp, type the following:

cd logging
git remote add upstream -m master git://github.com/kite-sdk/kite-openshift-logging-example.git
git pull -s recursive -X theirs upstream master
git push origin master

The push will do a full build and deploy, which will take a few minutes. When it’s done, the home page will be available at http://logging-[your-domain].rhcloud.com/, which is the URL that was printed to the console when you ran the the rhc app create command. You can also access your OpenShift applications at https://openshift.redhat.com/app/console/applications.

Note: You can see the webapp container logs if you log into the OpenShift machine (details on the OpenShift application page, under 'Remote Access') and type:

tail -f app-root/logs/jbossews.log

The page at http://logging-[your-domain].rhcloud.com/ presents you with a very simple web page for sending messages.

The message events are sent to the Flume agent over a socket, and the agent writes the events to the Kite dataset sink.

Send a few messages using the web form. Then wait 30 seconds for the sink to roll the file so that the data is visible. This page (which uses a Hive JDBC connection to run a query), shows all the events in the dataset: http://logging-[your-domain].rhcloud.com/all_events.jsp

Note: By default the application only has 1GB of disk space, which is not enough if you leave the application running for more than a few minutes. You can increase the amount of disk space via the web console, or by running:

rhc cartridge storage jbossews-2.0 -a logging --set 4

When you've finished with the application, delete it permanently with

rhc app delete logging