As an independent contractor working with Oracle databases, I frequently am asked about RAC experience. Here is my analysis of the product written in 2004 when Oracle went fro “i” to “g”.
As contract DBA for Guidance Software, I accomplished the forensic preservation of the Oracle database of the infamous 77 Million Users Data Breach. Under direction of the client’s legal office, the entire cage in the data center, several rows of equipment, were quarantined and cutoff from the network, and preserved prior to final analysis. I spent four months in that cage: 65 degrees.
The Oracle DB was sitting there on a downed, two node cluster with data residing on raw devices in a SAN.
The legal office wanted Oracle brought up with no chance of triggers firing or any other changes on the startup of the host/instance/database. That proved hard to do for a number of reasons.
The database had been running for six years through several versions of Oracle software. There were pieces left from rolling upgrades from versions eight through ten and the active Oracle11gR2 instance. Oracle homes everywhere, and oddities like a listener that had been working before hacked, which was located in a folder that had been renamed, also before.
I installed a NAS device and backed up over 7 terabytes of data then defined and demonstrated recovery with RMAN.
Several class action suits were anticipated. As of 2015, there are five on the books. My findings and my notebook were turned in with the database after four months of investigation. It’s about time for someone to call me for a restore 🙂
This is not exactly what I would call RAC experience as the commands used during this task crossed several versions and involved misconfiguration as well as having been hacked and down. I am not familiar with the normal, day-to-day operation of a RAC environment. I understand the theory… and cost.
The product prior to RAC was called OPS, Oracle Parallel Server, and I was the lead DBA for two installations. Again, never really worked with it day-to-day. I also implemented a Veritas cluster which used SAN features to make duplicate copies of the DB available in development and test. Less than 60 seconds of downtime was required to refresh either environment, on request.
A short learning curve will be required to use RAC; but, that’s one of the things that makes life interesting. Without a challenge, I probably would not want to do it again.