What this book covers

Chapter 1, Apache Karaf – Provisioning and Clusters, reviews what an OSGi is, the purposes, architectures, and components. We will introduce details about the Apache Karaf container, its architecture, and features. We will also introduce the question of how to manage multiple Apache Karaf instances.

Chapter 2, Apache Karaf Cellar, introduces Apache Karaf Cellar and the different cluster topologies that it can address. After the presentation of the Cellar architecture, we will perform our first cluster installation and manage different resources on the cluster using different techniques to monitor the current cluster state.

Chapter 3, Hazelcast, digs into the Cellar engine. After the introduction of Hazelcast, we will see different configurations that are useful for Cellar, especially around the network setup.

Chapter 4, Cluster Groups, shows you how to set up cluster groups in Cellar, allowing you to create a subset of nodes and target provisioning.

Chapter 5, Producers, Consumers, Handlers, Listeners, and Synchronizers, introduces you to the Cellar components used for the production, consumption, and transportation of cluster events between different nodes in a cluster.

Chapter 6, The Filtering of Cluster Events, shows you how to filter cluster events, allowing a fine-grained configuration of the resource synchronization in a cluster.

Chapter 7, DOSGi, shows that Cellar is not just a provisioning and synchronization clustering solution by introducing the first runtime clustering feature provided by Cellar: DOSGi. We will see how to use Cellar to implement remote communication between bundles located on different nodes using an example.

Chapter 8, Cellar and Camel, shows the second runtime clustering feature provided by Cellar by leveraging the camel-hazelcast component. Thanks to Cellar and Hazelcast, we will see how to implement remote communication between the Camel routes located on different nodes through an example.

Chapter 9, Roadmap, presents the new ideas and features that will come in the future versions of Cellar. This chapter gives an overview of the Cellar roadmap.