PRESENTOR:- KAMRAN SIDDIQUE SENIOR CONSULTANT/ARCHITECT (HA EXPERT) CGI DON’T WAIT OPPORTUNITY TO CREATE TECHNOLOGY…USE TECHNOLOGY TO CREATE OPPORTUNITY.

DATA GUARD

PRESENTOR:- KAMRAN SIDDIQUESENIOR CONSULTANT/ARCHITECT (HA EXPERT)

CGI

DON’T WAIT OPPORTUNITY TO CREATE TECHNOLOGY…USE TECHNOLOGY TO CREATE OPPORTUNITY

BASIC CONCEPTS

Basic Steps for Creating a Physical Standby database

MY TRICKS..

REFERENCES

QUESTIONS

AGENDA

A software An extension to Oracle RDBMS Protects DATA Takes data and automatically puts it

elsewhere. Makes DATA available for Failover. Maintain larger Distances. Automatic resync with Production database. High availability, data protection, and

disaster recovery for enterprise data.

WHAT IS DATA GUARD

Transactionally consistent copy of the primary database.

Using a backup copy of the primary database. Up to 30 Standby Databases and integrations

with DG . Once created, Data Guard automatically

maintains each standby database by transmitting redo data from the primary database and then applying the redo to the standby database.

Can be a SINGLE-INSTANCE OR RAC.

What is a Standby Database ???

DG configuration contains one Production database

Functions as Primary Role.Mainly accessed by Production applications.

Can be a Single-instance or RAC

Primary Database

1-PHYSICAL STANDBY A physical standby database is kept in sync with

the primary database by using media recovery to apply redo that was generated on the primary database.

A block-for-block identical copy of the primary database.

Excellent choice for disaster recovery. Data will be intact and consistent with data that

existed on the primary. Can receive and apply redo in read only-

access (11.1.0).

TYPES OF STANDBY DATABASES

2-LOGICAL STANDBY DATABASE Contains the same logical information as the

production database but physical organization and structure of the DATA can be different.

synchronization with the primary database through SQL Apply.

Transforms the data in the redo received from the primary database into SQL statements and then executes the SQL statements on the standby database.

Can be used for Reporting. Upgrade/Migration purpose with no downtime. Patch sets with no downtime.

TYPES OF STANDBY DATABASESContinue…

A fully updatable standby database. Receives and archives redo data from a

primary database (like physical/logical) Does not apply the redo data that it receives

(Differs from physical/logical) Redo apply starts once standby is converted

into physical standby. Temporary/updatable snapshot of a physical

standby. Conversion to physical standby could be a

lengthy process.

Snapshot Standby Database11.1.0

Database Version = 10.2.0.4 Enterprise 64-bit

Primary platform = Linux 64-bit)Secondary platform= Linux 32-bit)

You can not use DG Broker tool to manage this environment.

This restriction is lifted from Data Guard 11g onward.

My Trick…Different word sizes

one production database and one or more standby databases

connected by Oracle Net may be dispersed geographically No restriction on the distance. SQL command-line Data Guard Broker interface (DGMGRL) GUI interface integrated with EM.

Data Guard Configurations

A distributed management framework that automates the creation, maintenance, and monitoring of Data Guard configurations.

Oracle Enterprise Manager graphical user interface (GUI) or the Data Guard command-line interface (DGMGRL)

Create and enable Data Guard configurations Manage an entire Data Guard configuration from any

system in the configuration Manage and monitor Data Guard configurations that

contain Oracle RAC primary or standby databases Simplify switchovers and failovers Enable fast-start failover to fail over automatically when

the primary database becomes unavailable.

What is Data Guard Broker

1-Redo Transport Services Transmit redo data from the primary system

to the standby systems . Resolving any gaps in the archived redo log

files due to a network failure. Automatically detects missing or corrupted

archived redo log files on a standby system . Automatically retrieve replacement archived

redo log files from the primary database or another standby database

Data Guard Services

2-Apply Services Automatically apply the redo data on the

standby database to maintain consistency with the primary database.

Allows read-only access to the data

Data Guard Services

Physical standby---Data Guard uses Redo Apply technology.

Physical standby-- applies redo data on the standby database using standard recovery techniques of an Oracle database.

Logical Standby--Data Guard uses SQL Apply technology

first transforms the received redo data into SQL statements

Then executes the generated SQL statements on the logical standby database

Difference between physical and Logical Standby..with respect to services

3-Role Transitions

Switchover --role reversal between the primary database and one of its standby databases.Switchover –No Data Loss

Failover --failure of the primary databaseFailover --transition of a standby database to the primary roleFailover –Can configure Data Guard to ensure no data loss.

Data Guard Services

Both primary and standby databases must be set at the same compatibility mode as the minimum release

My Trick…Compatibility

A standby database cannot be open read-only in any environment that has binary-level PL/SQL-related incompatibilities between primary and standby databases

My Trick…Different binary-level

1-Maximum Protection Redo data needed to recover a

transaction must be written to both the online redo log and to the standby redo log on at least one synchronized standby database before the transaction commit

Zero Data Loss Processing on primary is

suspended if no standby is available.

Data Guard Protection Modes

2-Maximum Availability Minimal Data Loss Similar to Maximum protection mode If not standby database ,primary

operates as if it were in maximum performance mode to preserve primary database availability until it is again able to write its redo stream to a synchronized standby database.

Data Guard Protection Modes

3-Maximum Performance Default protection mode. Highest level of data protection that is

possible without affecting the performance of a primary database

Asynchronous in terms of transaction commitment.

primary database performance is unaffected by delays in writing redo data to the standby database(s).

Data Guard Protection Modes

Symmetric configuration with RAC at all sitesSame number of instances

Asymmetric configuration with RAC at all sites

Different number of instances Asymmetric configuration with mixture of

RAC and single instanceSome single-instance sites not running under Oracle Clusterware

Metalink note 413484.1

My trick..Architectural Touch...RAC and DATA GUARD topologies

Beginning with Oracle Database 11.1.0.7, a physical standby database can be used to execute a rolling database upgrade to a new Oracle Patch Set or database release by using the transient logical rolling database upgrade process

My Trick…Transient Logical Database Rolling Upgrades

Basic Steps for Creating a Physical Standby database

Two Vmwares (2.6.32-100.26.2.el5) 11.2.0.3.0 Primary ASM Secondary ASM Primary Database Name => Primary Primary DB_UNIQUE_NAME => Primary Standby DB_UNUIQUE_NAME =>Secondary Primary Hostname =>primary.localdomain Secondary Hostname =>

secondary.localdomain

HA VM

Enable Force Logging

SQL> ALTER DATABASE FORCE LOGGING;

Database altered.

Step 1Primary Site

On the primary node, connect to the primary database and create a PFILE from the SPFILE

create pfile='/home/oracle/stage/secondary.ora' from spfile;

Step 2

On the primary node, perform an RMAN backup of the primary database that places the backup pieces into the staging directory

RMAN> BACKUP DEVICE TYPE DISK FORMAT '/opt/oracle/stage/%U' DATABASE PLUS ARCHIVELOG;

RMAN> BACKUP DEVICE TYPE DISK FORMAT '/opt/oracle/stage/%U' CURRENT CONTROLFILE FOR STANDBY;

Step 3

DB_UNIQUE_NAME LOG_ARCHIVE_CONFIG LOG_ARCHIVE_DEST_2 DB_FILE_NAME_CONVERT LOG_FILE_NAME_CONVERT STANDBY_FILE_MANAGEMENT FAL_SERVER FAL_CLIENT SERVICE_NAMES DB_RECOVERY_DEST LOG_ARCHIVE_DEST_1

Step 4:-Initialization parameters

Before After

db_unique_name=CALGARY_DG db_unique_name=VANCOUVER_DG

INSTANCE_NAME=CALGARY instance_name=VANCOUVER

log_archive_config='dg_config=(VANCOUVER_DG,CALGARY_DG)

log_archive_dest_2='service=CALGARY valid_for=(online_logfiles,primary_role) db_unique_name=CALGARY_DG

db_file_name_convert='+DATA/CALGARY','+DATA/VANCOUVER','+RECOVERY/CALGARY','+RECOVERY/VANCOUVER'

log_file_name_convert='+DATA/CALGARY','+DATA/VANCOUVER','+RECOVERY/CALGARY','+RECOVERY/VANCOUVER'

standby_file_management=auto

fal_server='CALGARY'

fal_client='VANCOUVER'

service_names='VANCOUVER'

Example

log_archive_config='dg_config=(VANCOUVER_DG,CALGARY_DG)'

log_archive_dest_2='service=VANCOUVERvalid_for=(online_logfiles,primary_role) db_unique_name=VANCOUVER_DG' db_file_name_convert='+DATA/VANCOUVER/',’+DATA/

CALGARY/', ’+RECOVERY/VANCOUVER’,’+RECOVERY/CALGARY’ log_file_name_convert='+DATA/VANCOUVER/',’+DATA/

CALGARY/', ’+RECOVERY/VANCOUVER’,’+RECOVERY/CALGARY’ standby_file_management=auto fal_server=‘VANCOUVER' fal_client='CALGARY' service_names=CALGARY

CONFIGURE PRIMARY DATABASE FOR DG...Example

PRIMARY = (DESCRIPTION =

(ADDRESS_LIST =(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.2.105)(PORT = 1521))

) (CONNECT_DATA = (SERVICE_NAME = primary) ) )=================================================SECONDARY = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.2.106)(PORT = 1521)) ) (CONNECT_DATA = (SERVICE_NAME = secondary) ) )

Step 6 :-CONFIGURE ORACLE NET SERVICES

Create password file for standby database

orapwd file=orapwstandby password=xxxx

Password must be same as Primary password file

OR

Copy primary password file over standby site.

Step 5

$ rman target sys/oracle@primary auxiliary /

RMAN> DUPLICATE TARGET DATABASE FOR STANDBY;

Step 7- From the standby host, duplicate the primary database

The recommended number of standby redo logs is:

(maximum # of logfiles +1) * maximum # of threads If uses two online log files for each

thread. the number of standby redo logs should be (2 + 1) * 1 = 3. That is, one more standby redo log file for each thread.

Step 8 Add standby redo logs to standby database

Start managed recovery on the standby database:

SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE DISCONNECT;

Step 9:-

Create standby redo logs on the primary database to support the standby role

SQL> ALTER DATABASE ADD STANDBY LOGFILE THREAD 1 GROUP 5 SIZE 10M, GROUP 6 SIZE 10M, GROUP 7 SIZE 10M; SQL> ALTER DATABASE ADD STANDBY LOGFILE THREAD 2 GROUP 8 SIZE 10M, GROUP 9 SIZE 10M, GROUP 10 SIZE 10M;

CONFIGURE PRIMARY DATABASE FOR DG...Example

Data Guard configuration includes a primary database and up to 30 standby databases. These standby databases may be a mix of physical and logical standby databases.

My Trick…

To start log apply services on a physical standby database

ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT;

If the real-time apply feature is enabled, apply services can apply redo data as it is received, without waiting for the current standby redo log file to be archived

ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT

LOGFILE;

Applying Redo Data to Physical Standby Databases

DGMGRL> show configuration;

Configuration - DRSOLUTION

Protection Mode: MaxPerformance Databases: PRIMARY - Primary database SECONDARY - Physical standby database

Fast-Start Failover: DISABLED

Configuration Status:SUCCESS

END PRODUCT…

It is not necessary that the primary and the standby both be Oracle RAC databases, or both use ASM.

For example, the primary database may be running Oracle RAC with or without ASM, and the standby database(s) may be single-instance, with or without ASM.

Furthermore, the versions of ASM and CRS do not need to be the same between the primary and standby systems.

My Trick…

Exadata Database Machine: It is transparent to Data Guard whether primary and/or standby databases reside on an Exadata Database Machine or on other hardware, as long as the platform ID's of primary and standby systems within the same Data Guard configuration conform to the support requirements.

If Exadata Hybrid Columnar Compression (EHCC) is used, it is strongly recommended that both primary and standby databases reside on Exadata.

My Trick …

Verify Managed Recovery is Running (non-broker) on the standby

SELECT PROCESSFROM V$MANAGED_STANDBYWHERE PROCESS LIKE 'MRP%';

SELECT DELAY_MINSFROM V$MANAGED_STANDBYWHERE PROCESS = 'MRP0';

SQL> select database_role,protection_level,fs_failover_status from v$database;

V$DATAGUARD_STATUS

V$LOG &V$STANDBY_LOG…REDO LOG CHANGED.

V$MANAGED_STANDBY..RECOVERY PROGRESS

Select max(sequence#),thread# from v$archived_log where applied=‘YES’ group by thread#; Secondary

Select max(sequence#) from v$log;......primary

Data Dictionary

Dgmgrl / Connect sys/password@primary/secondary DGMGRL> CREATE CONFIGURATION

'DRSolution' AS PRIMARY DATABASE IS 'North_Sales' CONNECT IDENTIFIER IS North_Sales.foo.com;

DGMGRL> ADD DATABASE 'DR_Sales' AS CONNECT IDENTIFIER IS DR_Sales.foo.com MAINTAINED AS PHYSICAL;

Configuring Data Guard Broker

DGMGRL> SWITCHOVER TO STANDBY; Site "standby" was not found DGMGRL> SWITCHOVER TO "SECONDARY"; Performing switchover NOW, please wait... New primary database "SECONDARY" is opening... Operation requires shutdown of instance "primary" on database

"PRIMARY" Shutting down instance "primary"... ORA-01109: database not open

Database dismounted. ORACLE instance shut down. Operation requires startup of instance "primary" on database

"PRIMARY" Starting instance "primary"...

Switchover

1. Shutdown the new primary databaseIf using RAC then set database to unclustered: SQL> alter system set cluster_database=false scope=spfile;SQL> shutdown immediate

2. Startup the new primary in UPGRADE modeSQL> startup upgrade

3. Invalidate existing PL/SQL modules in preparation to convert the format required by the new primary.

SQL> spool utlirp.logSQL> @?/rdbms/admin/utlirpSQL> spool off

4. Restart the databaseIf using RAC then set database back to clustered: SQL> alter system set cluster_database=true scope=spfile;SQL> shutdown immediateSQL> startup

5. Recompile all invalid PL/SQL modules to be in the format required by the new primary database.SQL> spool utlrp.logSQL> @?/rdbms/admin/utlrpSQL> spool off

6. Verify that all expected packages and classes are valid.SQL> SELECT count(*) FROM dba_objects WHERE status='INVALID';SQL> SELECT distinct object_name FROM dba_objects WHERE status='INVALID';

MY TRICK…………………

Additional Role Transition Procedures when using mixed Oracle binaries:

Restore point An implicit guaranteed restore point is

created when a physical standby database is converted into a snapshot standby database and this restore point is used to flashback a snapshot standby to its original state when it is converted back into a physical standby database.

Steps to convert Physical Standby Database to the Snapshot Standby Database

STEP 1

A-

If not already configured , configure flash recovery area;Alter system set db_recovery_file_dest_size=<size>

B-

Set Flash recovery area.Alter system set db_recovery_file_dest=<path>

db_recovery_file_dest string +FLASHdb_recovery_file_dest_size big integer 3882M

Steps to convert Physical Standby Database to the Snapshot Standby Database Continue...

Step 2Bring the physical standby database to mount

stage.

Step 3Stop managed recovery if it is active.

SQL> alter database recover managed standby database cancel;

Database altered.

Steps to convert Physical Standby Database to the Snapshot Standby Database Continue...

Step 4

Convert physical standby database to snapshot standby database.

ALTER DATABASE CONVERT TO SNAPSHOT STANDBY;

The database is dismounted during conversion and must be restarted.

Steps to convert Physical Standby Database to the Snapshot Standby Database Continue...

SQL> shutdown immediateORA-01109: database not open

Database dismounted.ORACLE instance shut down.SQL> startupORA-32004: obsolete or deprecated parameter(s) specified for RDBMS instanceORACLE instance started.

Total System Global Area 835104768 bytesFixed Size 2217952 bytesVariable Size 507512864 bytesDatabase Buffers 322961408 bytesRedo Buffers 2412544 bytesDatabase mounted.Database opened.SQL> select open_mode,database_role from v$database;

OPEN_MODE DATABASE_ROLE-------------------- ----------------READ WRITE SNAPSHOT STANDBY

Steps to convert the Snapshot Standby Database to the Physical Standby Database

Step 1

Shutdown the snapshot standby database.

Step 2 Bring the database to the mount stage. Step 3Issue the command

ALTER DATABASE CONVERT TO PHYSICAL STANDBY;

Steps to convert the Snapshot Standby Database to the Physical Standby Database

Step 3Issue the command

ALTER DATABASE CONVERT TO PHYSICAL STANDBY;

Step 4 :-Shutdown the database and mount it . Step 5Start the media recovery process.

Steps to convert the Snapshot Standby Database to the Physical Standby Database

SQL> shutdown immediate

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL> startup mount

Database mounted.

SQL> alter database convert to physical standby;

Database altered.

SQL> shutdown immediate

ORA-01507: database not mounted

ORACLE instance shut down.

SQL> startup mount

Redo Buffers 2412544 bytes

Database mounted.

SQL> select open_mode,database_role from v$database;

OPEN_MODE DATABASE_ROLE

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

MOUNTED PHYSICAL STANDBY

SQL> alter database recover managed standby database disconnect;

Conversion by using DGMGRL

DGMGRL> CONVERT DATABASE "SECONDARY" TO SNAPSHOT STANDBY;

Converting database "SECONDARY" to a Snapshot Standby database, please wait...

Database "SECONDARY" converted successfully

Conversion by using DGMGRLContinue... DGMGRL> CONVERT DATABASE "SECONDARY" TO PHYSICAL

STANDBY;Converting database "SECONDARY" to a Physical Standby

database, please wait...Operation requires shutdown of instance "secondary" on

database "SECONDARY"Shutting down instance "secondary"...ORA-01109: database not open

Database dismounted.ORACLE instance shut down.Operation requires startup of instance "secondary" on

database "SECONDARY"Starting instance "secondary".

How to use Snapshot Database for 10g Create Restore PointCREATE restore point before_rw guarantee

flashback database; Failover the standby database: ALTER DATABASE ACTIVATE STANDBY

DATABASE Open Database in Read Write Mode:

How to use Snapshot Database for 10gcontinue..

Revert database back to standby mode: Shutdown the database; Startup database in mount mode; Flashback database;FLASH BACK DATABASE TO RESTORE POINT

before_rw; ALTER DATABASE CONVERT TO PHYSICAL

STANDBY;

Scenario 1: Creating a Configuration Scenario 2: Setting Database Properties Scenario 3: Enabling the Configuration and

Databases Scenario 4: Setting the Configuration Protec

tion Mode Scenario 5: Performing Routine Managemen

t Tasks Scenario 6: Performing a Switchover Operati

on Scenario 7: Performing a Failover Operation Scenario 8: Monitoring a Data Guard Config

uration

Scenarios

http://www.oracle.com/technetwork/database/features/availability/s291923-2-hughesallstatemaa-133334.pdf

http://www.oracle.com/technetwork/database/features/availability/s291923-2-hughesallstatemaa-133334.pdf

http://www.oracle.com/technetwork/database/features/availability/data-guard-esg-case-studies-133297.pdf

http://streaming.oracle.com/ebn/podcasts/db_insider/media/7548105_bank_of_aus_040709.mp3

Metalink note 413484.1

References

For any further informationcontact me at

[email protected]