Trafodion Elasticity enhancements

Abstract
This JIRA proposes changes to the Apache Trafodion Incubation configuration and operational elements used to define and operate a Trafodion cluster in a Trafodion instance. The changes proposed build on existing functionality for enhancing Trafodion to support elasticity by implementing the ability to add and delete nodes used by Trafodion components.

The concept of a cluster is defined in Trafodion through the configuration of nodes in the ‘sqconfig’ text file, the Trafodion configuration file. This configuration file is compiled to generate a set of files used to start and stop a Trafodion instance. The files generated consist of a configuration database and scripts which presently contain fixed, i.e., hardcoded, configuration topology attributes of a configured Trafodion instance. This proposal addresses this hardcoded configuration topology issue by adding new configuration commands in the Trafodion Foundation’s monitor components, changing the methodology in the scripts generated, and extending the use of the configuration database currently in use.

Objectives
The objective of this proposal is to implement elasticity capabilities in Trafodion to match or exceed the elasticity capabilities of other modules in the Hadoop eco system.

This focuses on the Trafodion Foundation functionality. Specifically, the monitor components which use the configuration of nodes that define a Trafodion cluster are enhanced to provide at set of primitive commands to add and delete nodes as well as the generation of events to existing processes in the instance of the addition or deletion of member nodes to the cluster configuration.