Overview
Open High Availability Cluster Geographic Edition (OHACGE) already supports two forms of data replication:
- Host-based, with Sun StorageTek AVS
- Storage-based, with Hitachi TrueCopy and EMC SRDF
Services held in OHAC resource groups are protected by OHACGE by encapsulating them in protection groups (PGs). Device groups (DG) are added to these PGs represent the individual replicated data stores. With the advent of this project, the term 'device group' will no longer be sufficiently broad and thus will be superceded by the term 'replication component' or 'replication object'.
Currently, extending OHACGE to support PostGreSQL or MySQL database replication technologies requires detailed knowledge of the source Java code and MBean structure, and an ability to program to these interfaces.
This project proposes to develop a Script Based Plug-in (SBP) MBean that will provide a feature for OHACGE analogous to the Generic Data Service (GDS) on OHAC. This will lower the barriers to adding new replication software support.
The SBP MBean will provide a set of SBP specific protection group and replication component properties that will be configurable on a per PG and DG basis. These properties would enable external scripts or programs to be called with a set of pre-defined arguments.
Users of the SBP will be required to develop scripts or programs that can be called by the SBP MBean in response to each of the actions performed by OHACGE, e.g configuration setup, configuration validation, switch-over, take-over, etc.
Project Goals
The project will have the following goals:
- Provide a new OHACGE MBean to support Script Based Plug-ins.
- Provide a set of protection group and replication component properties that define the scripts/programs and arguments that an OHACGE administrator/developer must provide in order to use this framework.
A separate project will produce an example Script Based Plug-in to demonstrate the use of this feature.
Status
- November 17th 2008 - Code putback expected this week.
Documentation
Getting involved
- Talk with people or search the archives in the ha-clusters:discuss discussion group