- monitoring metrics for the server itself and for webapps
- monitoring metrics and editing configurations for datasources, connection factories, JMS topics and queues, and the host JVM
- creating and deleting datasources, connection factories, and JMS topics and queues
- executing scripts that reside within the JBossAS bin directory
Under the hood, Embedded Jopr is based on the Jopr project, which is in turn based on the RHQ project. RHQ is an open source enterprise management infrastructure framework, which includes a simple yet full-featured API for writing management plugins for managing just about anything under the sun. RHQ also bundles a set of plugins for managing popular open source products such PostgreSQL and Apache Web Server. The Jopr project consists of the RHQ platform, along with a set of additional plugins for managing JBossAS and other JBoss projects - Hibernate, JBossWeb, etc.
To understand how Embedded Jopr leverages RHQ and Jopr, let's first take a step back and look at the architecture of Jopr. It consists of a single Server with multiple Agents reporting into it. There is one Agent running on each machine that is hosting applications to be discovered and managed by Jopr. Each Agent contains a Plugin Container that in turn contains plugins for each of the supported managed products. The Agent essentially wraps the Plugin Container in a standalone process that can communicate with the remote Jopr Server. The Server stores all data reported by the Agents in a central database and provides a web-based GUI for viewing and updating that data.
The goals of Embedded Jopr were considerably less complex than those of its older sibling Jopr. Embedded Jopr sought only to manage a single JBossAS instance. Because we did not need to manage multiple products running in separate OS processes, and because the JBossAS instance being managed was a Java-based application server, we could embed the Jopr Plugin Container inside an application deployed to the JBossAS instance itself - no need for a separate Agent process.
As for what type of application in which to embed the Plugin Container, we had a couple requirements:
- provide a way to bootstrap the embedded Plugin Container when the JBossAS instance starts up
- provide a web-based interface to the management data collected by the Plugin Container - real-time monitoring only
Since we only needed to provide real-time monitoring, there was no need to persist any of the collected management data, which meant we didn't require a database or Hibernate, EJB, etc. The Servlet spec provided the necessary APIs for running our bootstrap code at webapp deployment time, and JSF (which is bundled with JBossAS 4.2 and later) provided a nice framework for building a GUI. So the most sensible type of application in which to embed the Plugin Container was a webapp. We were also able to leverage Facelets, Seam, and RichFaces - extensions to JSF that allowed us to create a robust and maintainable web application.
Jopr includes RHQ plugins for managing a number of different products - JBossAS, Apache Web Server, PostgreSQL, Oracle, etc. Embedded Jopr did not need to include all of these plugins - it only needed the plugins required to manage JBossAS, its deployed services, and its host JVM. This allowed us to keep Embedded Jopr relatively lean (about 9 MB).
With such powerful foundational technologies, Embedded Jopr promises to soon become one of the nicest administration consoles out there. We hope to see lots of participation from the community, since this is one project that will greatly benefit all JBossAS users. The main goal for Embedded Jopr 1.1 is to add support for JBossAS 5.