Data Guard in the E-Business Suite Environment

Copyright 2010 by Chad Johnson

Chad Johnson

Polk County Board of County Commissioners

Agenda

What is Data Guard?

Why do I care?

How does it work?

What about the E-Business Suite?

Technical stuff

Assumptions

Database is 10g or 11g

Non-RAC environment

Disaster Recovery is Primary Goal

*nix Operating System

Not Using Data Guard Broker or Grid Control

What is Data Guard

Component of Oracles Maximum Availability Architecture (MAA)

Maintains an exact copy of a database

Native Oracle tool Native Oracle tool

Benefits of Data Guard

Free

Simple to use

Native Oracle

Fully supported

Integrated

RAC, ASM, RMAN

Protects against data corruption

ZERO data loss (caveat emptor)

Terminology

Primary database

Standby databases

Physical

LogicalLogical

Active Data Guard (11g)

Switchover vs. Failover

Terminology

Protection modes

Maximum Protection

Maximum Availability

Maximum PerformanceMaximum Performance

Transport services

SYNC

ASYNC

Performance Considerations

Available network bandwidth

Round trip network latency

Standby servers I/O performance

The effects are cumulative

Wait Events

SELECT event, time_waited

FROM V$SYSTEM_EVENT

WHERE event LIKE 'LNS wait%';

EVENT TIME_WAITED (centaseconds)

-------------------- ---------------

LNS wait on ATTACH 74

LNS wait on SENDREQ 3820

LNS wait on DETACH 0

LNS wait on LGWR 0

Transactions

A logical unit of work that must succeed in its entirety or fail completely

Why do I care? Why do I care?

Transfer money from savings to checking

So, when IS my data safely written to disk?

Data in an Oracle Database

Redo a group of change vectors, each of which is a description of a change made to a single block in the databasedatabase

Redo is the key to Data Guard

Local and remote destinations

ARCnOnlineRedo Log Files

LGWR

Primary Database

Data Files

Archived Redo Log

Files

Online Redo

Log Files

Primary Database

LNS

LGWR

StandbyRedo

Log Files

StandbyDatabase

Archived Redo Log

Files

Real Time Apply

MRP

ARCn

RFS

LNS Process

Data Guard in the House

Ship redo, apply redo, repeat

Log Network Server (LNS)

Remote File Server (RFS)

Fetch Archive Log (FAL) client and server

SYNC and ASYNC

E-Business Suite Considerations

Data Guard is a database-only tool

Application and database tiers are tightly coupled

Configure application tier with Configure application tier with adclonectx.pl

Secondary Data Center Should:

Be physically distant from primary

Have sufficient bandwidth

Have reliable network services to primary data center and to users primary data center and to users point of presence

Have same type of servers with same disk layout (for simplicity in DR)

Secondary Data Center Should:

Have same OS and Oracle directory structure to correctly resolve compiled references if PL/SQL code is natively compilednatively compiled Plsql_code_type=INTERPRETED #Default 11i setting

Have other hardware and software needed for backups, monitoring, system management, etc.

WARNING!

The technical (i.e. fun) stuff begins now

This is a good time for general questions

Create a Physical Standby

The database name must be the same for the primary and all physical standbys

The host/server names and the db_unique_name must be differentdb_unique_name must be different

The user & group IDs of the Oracle and apps owner accounts must be the same

Consider copying concurrent manager log & out files to standby server (rsync)

Create an EBS Standby

Enable forced logging

Configure Oracle Net communications

Create a password file (on primary)

Adjust init.ora parameters Adjust init.ora parameters

Add standby redo logs

Invite communications from standby

Create an EBS Standby

Pre-clone the database and apps tiers

Copy APPL_TOP and apps tech stacks

Copy ORACLE_HOME and database files

Generate standby control file and copy it Generate standby control file and copy it to standby server

Gather temporary file info

Create an EBS Standby

File based configuration on standby application server

File based configuration on standby database serverdatabase server

Stop listener on standby database server

Configure Oracle Net for redo transmission

Create an EBS Standby

Start listener - standby database server

Modify init.ora parameters on standby

Mount physical standby

Start redo processing on standby Start redo processing on standby

Start shipping redo to standby

Verify redo is being shipped

Add temp files to standby

Rsync log and out files (optional)

My Oracle Support Notes

Note 216212.1 Business Continuity for Oracle Applications Release 11i, Database Releases 91 and 10g

Note 1068913.1 Business Continuity Note 1068913.1 Business Continuity for Oracle E-Business Release 11i Using Oracle 11g Physical Standby Database

Thank You

Questions and Answers