173_oracle rac from dream to production_1.0.0

8/7/2019 173_Oracle RAC From Dream To Production_1.0.0

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In RAC We Trust

ORACLE - From Dream To Production

Plamen Zyumbyulev

,, Let someone k n o w

BGOUG Gabrovo 22.04.2005


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Presentation Goals

Describe the major steps in RAC implementation

Show and explain the main problems and obstacles

Show and explain solution and workarounds

Give some practical ideas and variations

Try to look at the problems from different angles

Non-Goals Explain RAC concepts and fundamentals

Show ALL aspects of RAC


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Agenda

Introduction

RAC Installation

High Availability Configuring

Testing and Tuning RAC

Implementing RAC in production


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Introduction


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RAC Installation

Problems

Solutions


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Problems

Need to evaluate and purchase cluster hardware

Need of knowledgeable OS, High Availability,Network and Storage professionals

All this takes time


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Solutions

RAC on Single Node

RAC on Single VMware Node RAC on Multiple VMware Nodes

RAC and Network Block Device

All of the solutions presented here are for testingpurposesONLY. These configurations are not

certified or supported by Oracle Support Services

Other Solutions


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RAC on Single Node

Why not?

Metalink Note:241114.1 - Step-By-Step Installation ofRAC on Linux - Single Node (Oracle9i 9.2.0 with OCFS)

Key Points No need of fencing configuration No need of using clustered file system or raw devices No need of multiple oracle homes (ORACLE_HOME)


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RAC on Single Node(contd)

Key Points (contd) One oracle user with 2 or more profiles one for every

instance. (e.g. .rac1, .rac2, )

zyumix:/# su - oracle

oracle@zyumix:~$ . rac1

oracle@zyumix:~$ echo $ORACLE_SIDrac1

zyumix:/# su - oracle

oracle@zyumix:~$ . rac2

oracle@zyumix:~$ echo $ORACLE_SID

rac2


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Key Points (contd) Oracle Universal Installer needs Clusterware software in

order to install RAC option.

Disadvantages


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Server A

Instance A

Server B

Instance B

DatabaseDatabase

Client sideload balancing

Server side

load balancing

Listener

A

Listener

B


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RAC on Single VMware Node

Even easier !!! The Oracle-on-Linux VMware Cookbook -

http://www.oracle.com/technology/tech/linux/vmware/cookbook/index.html

An easy, hands-on, step-by-step guide describing how-toinstall VMware, Linux (RHEL/SLES) and Oracle RAC(again on single node)

VMware Workstation (90-day free eval; registration required)RHEL3 (not free) , SLES8 (not free)

Disadvantages
http://www.oracle.com/technology/tech/linux/vmware/cookbook/index.htmlhttp://www.oracle.com/technology/tech/linux/vmware/cookbook/index.html


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RAC on Multiple VMware Nodes

VMware GSX/ESX Server permits the sharing of plain diskswith multiple virtual machines running on the same host,

provided the disk in question is a SCSI disk.

This approach is very powerful but complex. You can createvery complex environments multiple NICs, switches, disksetc.

Now there are a number of nodes although virtual

Disadvantages


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RAC and Network Block Device

This solution allows you to build scalable and high availabledatabase system only with common Intel PCs connected intoEthernet network.

In this solution, a standard shared disk subsystem is replacedby a native Linux technology - Network Block Device(NBD) that maps remote files to local block devices (e.g./dev/nb0) via TCP/IP network. One computer (notnecessarily Linux machine) serves as data storage for allcluster nodes (Linux machines) instead of expensive diskarray.


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RAC and Network Block Device(contd)

With this thing compiled into the kernel, Linux can use a

remote server as one of its block devices. Every time the

client computer wants to read /dev/nd0, it will send a requestto the server via TCP, which will reply with the data

requested.

The remote resource doesn't need to be a whole disk or evena partition. It can be a file.


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Typical configuration Simple NBD configuration


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InstallationBoth client and server machines are with RHEL3

Download source from http://nbd.sourceforge.net/ As root do

bunzip2 nbd-2.7.3.tar.bz2

tar -xvf nbd-2.7.3.tar

cd nbd-2.7.3 ./configure

make

make install
http://nbd.sourceforge.net/http://nbd.sourceforge.net/


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Creating new empty files at NBD server[root@rac2 root]# dd if=/dev/zero of=/u01/oradata/rac/system.01 count=300 bs=1M300+0 records in

300+0 records out

314572800 bytes transferred in 1.683993 seconds (186801738 bytes/sec)

[root@rac2 root]#

Running NBD serverSyntax: nbd-server

[root@rac2 root]# nbd-server 4101 /u01/oradata/rac/system.01

[root@rac2 root]#


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NBD clientNBD client must be run as root (because of kernel parts of

NBD). Before starting NBD client you would have to installLinux kernel NBD module

Installing ndb module RHEL3

[root@rac3 root]# rpm -Uvh kernel-unsupported-2.4.21-4.EL.i686.rpm

warning: kernel-unsupported-2.4.21-4.EL.i686.rpm: V3 DSAsignature: NOKEY, key ID db42a60e

Preparing...########################################### [100%]

1:kernel-unsupported########################################### [100%]

[root@rac3 root]#


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NBD client (contd) Loading nbd module

[root@rac3 dev]# lsmod | grep nbd

[root@rac3 dev]# modprobe nbd[root@rac3 dev]# lsmod | grep nbd

nbd 16388 0 (unused)

[root@rac3 dev]#

running nbd clientSyntax: nbd-client /dev/nb

[root@rac3 dev]# nbd-client rac2 4101 /dev/nb0Negotiation: ..size = 307200KB

bs=1024, sz=307200

[root@rac3 dev]#


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Now block devices are configured and it is possible to access

remote data. Oracle Real application clusters need raw access

to shared disk subsystem so mapping raw devices to blockdevices is needed. This could by done with standard raw

command.

Syntax: raw /dev/raw/raw /dev/

[root@rac3 root]# raw /dev/raw/raw1 /dev/nb0

/dev/raw/raw1: bound to major 43, minor 0

[root@rac3 root]#


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Other Solutions

RAC and FireWireBuild Your Own Oracle RAC 10gCluster on Linux

and FireWirehttp://www.oracle.com/technology/pub/articles/hunter_rac10g.html

RAC and NFS

LockingCaching

Write through cache
http://www.oracle.com/technology/pub/articles/hunter_rac10g.htmlhttp://www.oracle.com/technology/pub/articles/hunter_rac10g.html


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HA Configuration


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Simplified RAC schema

DatabaseDatabase

NET


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HA System


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Maximum Availability

Architecture

Dedicated Network

Primary Site

Application Server

Secondary Site

Application Server

Data Guard


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Extended Distance Clusters

Dedicated Network

Primary Site

RAC

Application Server

Secondary Site

Application Server

Virtualization storage layer

What about the Quorum Server???


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Extended Distance Clusters(contd)

Resolving Distance Problems Application partitioning

gc_files_to_locks

Wavelength Division Multiplexing Dense Wavelength Division Multiplexing DWDM

Coarse Wavelength Division Multiplexing CWDM

ACTIVE_INSTANCE_COUNT *.active_instance_count = 1

*.cluster_database_instances = 2


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Testing and Tuning RAC

Introduction

RAC testing steps

Functional Application Tests RAC High Availability tests

Scalability tests

Digging into RAC performance problems


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Introduction

Testing isnt trivial !!!

Classical testing/tuning methods. Always tune single instance first!

Specific RAC issues

RAC aware tools


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RAC testing steps

Functional Application Tests

RAC High Availability tests Be aware about the timeouts!!!

Scalability tests

173_oracle rac from dream to production_1.0.0

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