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Yesterday i completed a 11g Release 2 real application clusters installation on 64 bit Oracle Enterprise Linux 4. The installation process is very similar to the 10g and 11gr1 installations, but much simpler. This was a two node cluster. There are some new concepts that are introduced in 11gR2 real application clusters. Below are some of my notes on 11gr2 new features for Rac and detailed steps that i followed to complete the installation.

Some new concepts in 11gR2 Rac

Oracle clusterware and ASM now are installed into the Same Oracle Home, and is now called the grid infrastructure install.

Raw devices are no longer supported for use for anything (Read oracle cluster registry, voting disk, asm disks), for new installs.

OCR and Voting disk can now be stored in ASM, or a certified cluster file system.

The redundancy level of your ASM diskgroup (That you choose to place voting disk on) determines the number of voting disks you can have.
You can place

• Only One voting disk on an ASM diskgroup configured as external redundancy
• Only Three voting disks on an ASM diskgroup configured as normal redundancy
• Only Five voting disks on an ASM diskgroup configured as high redundancy
  

The contents of the voting disks are automatically backed up into the OCR

ACFS (Asm cluster file system) is only supported on Oracle Enterprise Linux 5 (And RHEL5), not on OEL4.

There is a new service called cluster time synchronization service that can keep the clocks on all the servers in the cluster synchronized (In case you dont have network time protocol (ntp) configured)

Single Client Access Name (SCAN), is a hostname in the DNS server that will resolve to 3 (or at least one) ip addresses in your public network. This hostname is to be used by client applications to connect to the database (As opposed to the vip hostnames you were using in 10g and 11gr1). SCAN provides location independence to the client connections connecting to the database. SCAN makes node additions and removals transparent to the client application (meaning you dont have to edit your tnsnames.ora entries every time you add or remove a node from the cluster).

Oracle Grid Naming Service (GNS), provides a mechanism to make the allocation and removal of VIP addresses a dynamic process (Using dynamic Ip addresses).

Intelligent Platform Management Interface (IPMI) integration, provides a new mechanism to fence server’s in the cluster, when the server is not responding.

The installer can now check the O/S requirements, report on the requirements that are not met, and give you fixup scripts to fix some of them (like setting kernel parameters).

The installer can also help you setup SSH between the cluster nodes.

There is a new deinstall utility that cleans up a existing or failed install.

And the list goes on an on.

I have broken up the installation process into 3 distinct documents, which can be found below

Installing 11gr2 grid infrastructure

Installing 11gr2 Real Application Clusters

Creating the 11gr2 Clustered database

Oracle has for a while had a rac assurance team (A team within oracle support, in the HA/Rac support team) that engages proactively with new rac customers. The Rac Assurance team used to provide the new customers with a “starter kit” of documents that  include

1. A Rac best practices document
2. A Step by Step installation guide
3. Recommended patches
4. A test plan.

If the customer follows these best practices, it sets them up with a solid foundation to be successful with their new  Rac implementation.

Now these test kits are public, you can access them by accessing metlink note 810394.1

You can also log a tar in metalink and ask support for the “Rac Starter Kit”, and they will give you the platform specific starter kit that includes the list of recommended patches.

In my numerous engagements with customers, assisting them with Oracle Rac installations, i have found that providing the customer with a checklist of tasks to be performed before the installation, and reviewing it with their Database/Server/Storage/Network  Administrator’s  help in a smooth RAC installation.The checklist only lists the tasks, but does not go into step by step details regarding how to perform the task. For the details, i then point them to the Oracle Installation and Configuration Guides (Links to which can be found in the checklist itself) and relavent metalink notes.

Below are links to the checklists that I use for 11g Installations on Linux and Solaris. All pointers to errors and improvements are welcome.

Oracle Real Application Clusters, 11g Installation Checklist for Redhat Enterprise Linux 5 and Oracle Enterprise Linux 5

Oracle Real Application Clusters, 11g Installation Checklist for Solaris

Updated this post from Ubuntu Jaunty to Lucid.

Unless you have been living on one of the planets orbiting alpha centauri (or if you have nothing to do with computers, in which case you would not be reading this post), you must have heard of ruby on rails.

Below are the steps i went through to get ruby and rails installed and configured on a Ubuntu Jaunty (10.04) system.

Make sure that you have installed Oracle 11g or the Oracle 11g instant client on the Ubuntu server, before you start.

Get the ruby packages for ubuntu

sudo apt-get install ruby  ruby-dev  libopenssl-ruby1.8 irb ri rdoc

sudo apt-get install sqlite3

sudo apt-get install libsqlite3-ruby libsqlite3-dev

Download, Install setup Gems

sudo ln -s /usr/bin/gem1.8 /usr/local/bin/gem

Install Rails 2

sudo gem install rails

Download and install the ruby interface for oracle

Download ruby-oci8 from http://rubyforge.org/frs/?group_id=256

http://rubyforge.org/frs/download.php/69454/ruby-oci8-2.0.4.tar.gz

tar -xzvf ruby-oci8-2.0.4.tar.gz

cd ruby-oci8-2.0.4/

make

sudo make install

Get the Enhanced ActiveRecord adapter for oracle

wget http://rubyforge.org/frs/download.php/64456/activerecord-oracle_enhanced-adapter-1.2.2.gem

sudo gem install activerecord-oracle_enhanced-adapter-1.2.2.gem

You are all set to write and test your first ruby program using the rails framework .

Please see my followup post on writing a simple rails program with 11g