Oracle12c data guard farsync and whats new

Oracle 12c Data Guard – Far Sync and what’s newAuthor & Presenter: Nassyam BashaDate: 22-Feb-2014

© 2014 Pythian2

Nassyam Basha• Post Graduation in computers from University of Madras• 7 Years of experience as Oracle DBA and exposure with

dBase and FoxPro• Currently working for The Pythian Group • 10g,11g Oracle certified professional• Blogger www.oracle-ckpt.com • Frequent OTN contributor (CKPT)• Co-Author of Oracle 11gR2 Data Guard administration beginners Guide – PACKT • nassyambasha Nassyam Basha

http://www.oracle-ckpt.com/

https://community.oracle.com/people/CKPT

https://twitter.com/nassyambasha

https://twitter.com/nassyambasha

http://www.packtpub.com/oracle-data-guard-11gr2-administration-beginners-guide/book

• Recognized Leader:– Global industry-leader in remote database administration services and consulting for Oracle,

Oracle Applications, MySQL and SQL Server– Work with over 150 multinational companies such as Forbes.com, Fox Sports, Nordion and

many more to help manage their complex IT deployments• Expertise:

– One of the world’s largest concentrations of dedicated, full-time DBA expertise. Employ 7 Oracle ACEs/ACE Directors

– Hold 7 Specializations under Oracle Platinum Partner program, including Oracle Exadata, Oracle Golden Gate & Oracle RAC

• Global Reach & Scalability:– 24/7/365 global remote support for DBA and consulting, systems administration, special

projects or emergency response

Why Companies Trust Pythian

3 © 2014 Pythian

http://www.upenn.edu/

http://www.fimcareers.com/

http://www.mdsinc.com/

© 2014 Pythian4

Oracle Data Guard Journey7.3 -Introduced in this version as “standby database” 8i

- Physical standby database , Managed recovery of standby , Remote archiving of redo logs

9i- Protection modes, Data Guard Broker, Switchover/Failover, Automatic GAP

resolution & Synchronization, Logical standby , Cascaded

10g- Real-Time Apply, More enhancements with Configurations, FSFO, Flashback

Database, SRL support on Logical standby database.

11g- Active Data Guard, Snapshot Standby, Heterogeneous platform support,

Rolling upgrade, tuning reports.

12c- Fast Sync, Far Sync, Real-Time Cascade standby, DBMS_ROLLING

© 2014 Pythian5

What’s new in 12c Data Guard?1. Fast Sync2. Far Sync3. Real-time Cascade standby database4. SYSDG role5. Online standby data file movement 6. Recover standby database using primary

service7. DBMS_ROLLING

© 2014 Pythian6

1. Protection modes & Fast Sync• Maximum Performance: Primary database never waits for any acknowledgment

from standby destinations to complete a transaction. The default mode. (ASYNC/NOAFFIRM)

• Maximum Protection: No data loss even if primary database fails, to reach the protection level the redo data needed to recover transaction must be written to both the online redo log and to the standby redo logs. (SYNC/AFFIRM)

– Recommended to have minimum two standby database(s)

• Maximum Availability(12c): This has the ability to run as a Maximum Protection or Maximum Performance mode depending on the accessibility of standby databases. . (SYNC/AFFIRM-NOAFFIRM)

- Maximum protection in maximum Availability MAX_PERFORMANCE MAX_PROTECTION MAX_AVAILABILITYASYNC SYNC SYNCNOAFFIRM AFFIRM AFFIRM/NOAFFIRM

© 2014 Pythian7

Performance with Maximum Availability – Fast Sync• Maximum availability with SYNC/AFFIRM – Traditional Primary performs write operations and waits for acknowledgement until redo has been transmitted synchronously to the standby and written to the disk. • SYNC/NOAFFIRM – From 12c The primary performs write operations and waits only for acknowledgement that the data has been received on the standby, Chances of data loss in the event of a failure as primary does not check for redo writes to disk on standby.

© 2014 Pythian9

Far Sync – Road Map (Topology 1:n)• In legacy configurations, you can have multiple standby databases based

on the destination numbers(LOG_ARCHIVE_DEST_n), – can have mixed combination of either physical or logical standby.

• What is throughput and network traffic from one to many topology? • Is your all of standby sites will have same network speed across global? • What happens if you have only one data centre very far distance?

© 2014 Pythian10

Far Sync – Road Map (Cascade Standby) • Introduced in 9iR2 • Reduces load on primary, whereby a standby database receives its redo

data from another standby database• Disadvantage: you must have whole database structure (if VLDB) ?

© 2014 Pythian11

Far Sync - Introduction• Far Sync introduced in 12c and its an extension of Cascade standby database

• Far Sync supports both Physical standby and also Logical standby and it requires Oracle Active Data Guard License

• Far Sync supports either Maximum Availability or Maximum Performance… Why?

• It’s a light and Semi database… How?- It contains only configuration file (SPFILE), control file and standby redo log

files and it cannot be opened because it doesn’t contain any data files. - No storage cost and It consumes very less server resources (CPU, Memory…)

• Far Sync supports Data Guard Broker.

• Far sync instance acts as a redo log repository to remote standby databases.- compression of redo can be enabled with advanced compression license.

© 2014 Pythian12

Far Sync – Best Practices• Create a far sync instance close to the primary database to overcome/avoid network

latency bottlenecks and gain performance benefits while transmitting redo.

• As soon as Far Sync receives redo data it transmits to standby database(s) asynchronously

© 2014 Pythian13

Far Sync – Zero Data Loss Protection- How?• As soon as Far Sync receives synchronous redo from primary, it also completes

sending committed transactions to the standby destination(s) of Data Guard configuration.

- My data is safe in standby database(s)• You could configure FSFO for failover operations or use manual method.

© 2014 Pythian14

Far Sync – Implementation: Prerequisites Change to SPFILE in case of PFILE. Create Password file on Primary

- Copy password file to Far Sync instance and standby servers Primary database should be in Archive log mode Enable FORCE LOGGING on Primary database Listener configuration on all locations (Primary, Far Sync and Standby) Network connection

- Primary to Far Sync and vice versa- Far Sync to remote standby database(s) and vice versa - Primary to remote database(s), useful in case of switchover and any checks

Create Standby redo logs. - Creation of SRL’s on overall Data Guard configuration including primary will helps us in case of role transition

- Avoid multiplexing of SRL (standby redo logs)

© 2014 Pythian15

Far Sync – Implementation: Know your environment• In this scenario, We have a Primary database and one standby, Now we introducing

Far Sync instance to transmit redo information through it.

• Create standby redo logs on primary– SRL’s on Far Sync will be created by the use of LOG_FILE_NAME_CONVERT

• Now create the control file for Far Sync instance from primary database and mount on Far Sync

DATABASE_ROLE DB_UNIQUE_NAME Oracle Net

Primary CANADA CANADA

Far Sync CANFAR CANFAR

Standby INDIA INDIA

© 2014 Pythian16

Far Sync – Implementation• The new values of parameters from all destinations are

© 2014 Pythian17

Far Sync – Implementation(critical)• Increase the protection mode to Maximum availability.

• Black BoxPrimary database is in MAXIMUM AVAILABILITY modeChanging standby controlfile to MAXIMUM AVAILABILITY modeChanging standby controlfile to RESYNCHRONIZATION levelStandby controlfile consistent with primary

• Recovery (MRP)– When recovery comes into picture, probably recovery can started from Far Sync?

Then you will run into “ORA-01665: control file is not a standby control file” – Moreover there are no data files to update any committed transaction, its any

instance which works as broker between primary and standby database, Recovery(MRP) should start only on standby database(s).

© 2014 Pythian18

Far Sync - Validation• After the successful configuration of introducing Far Sync, Overall status of the configuration

• SRL’s are being used?

• Parent and child relationship of Data Guard configuration.

© 2014 Pythian19

Far Sync: Flexible • There may some possible chance, when your far sync instance may unavailable, so

configure Data Guard in such way to maintain zero data loss. - alter system set log_archive_dest_2='service=canfar SYNC AFFIRM MAX_FAILURE=1

ALTERNATE=LOG_ARCHIVE_DEST_3 DB_UNIQUE_NAME=canfar VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE)';

- alter system set log_archive_dest_3='service=india ASYNC ALTERNATE=LOG_ARCHIVE_DEST_2 DB_UNIQUE_NAME=india VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE)';

• Redo will be sent asynchronously to alternate destinations when far sync instance is down

• Once back, Data Guard automatically resynchronizes far sync (canfar) instance.

Far Sync: High Availability • After role transition (Switchover), will be the commit response time remains

same between new primary and the Far Sync-1 (canfar)? • To avail maximum availability for zero data loss establish a new far sync

instance near to the primary.

© 2014 Pythian20

ASYNC

SYNCFar Sync-1

Switchover

Switchover

Standby

Distance ?

Far Sync-2

SYNCASYNC

Standby

Primary

After switchover

© 2014 Pythian21

Far Sync – Add second far instance• Create SPFILE from new/modified PFILE• Copy Password file• Network connection between all the locations. • Create new Far Sync control file from Primary database and mount.• Ensure SRL’s are available for maximum availability in case of role

transition

© 2014 Pythian23

Real-Time Cascaded Standby DatabasesReal-Time cascaded – Another notable feature of 12c

– Must have Active Data Guard License– Cascading Standby can be in any Protection Mode– A Cascading Standby Database can serve one or multiple terminal Standby

Databases

• Data Guard Broker now supports cascade standby• Standby should be either Physical or Far Sync Standby (if available) - You cannot cascade a physical standby from logical standby

• Add DB_UNIQUE_NAME, LOG_ARCHIVE_CONFIG, LOG_ARCHIVE_DEST_n with ‘VALID_FOR=(‘STANDBY_LOGFILES’,’STANDBY_ROLE)’

– Standby Redo Logs(SRLs) Should be created on cascading standby database. – FAL_SERVER on terminal standby should set to the cascading standby or primary database. – DEST_1 to DEST_10 supports to Real-Time if ASYNC used, if do not specified ASYNC then it works

under non-real time. Especially DEST_11 to DEST_31 supports to only real time transport mode.

© 2014 Pythian25

SYSDG Role• So far for any Data Guard operations performed using SYS, From now SYSDG role can

granted to user to perform only specific to Data Guard operations. • If you want to manage with SYSDG role then do not forget to copy to standby

database(s)– SYSDG role contains ALTER SYSTEM,SELECT ANY DICTIONARY, ALTER DATABASE, ALTER SESSION and all

DGMGRL commands

© 2014 Pythian27

Online standby data file movement• Online standby data file is feature of 12c and this is applicable either primary or

standby but now it is more flexible… How?– No need to terminate the recovery (MRP)– No need to set STANDBY_FILE_MANAGMENT to MANUAL– If using ADG no need to bounce database to mount either.

© 2014 Pythian29

Recover standby database using primary serviceFrom 12c to fill huge archive lags, incremental backups on fly procedure can be performed for faster and simple form of recovery by using service name.Should be in mount status or else recovery cannot be performed in open status and data file fall into exclusive enqueue

– No need to have backup from primary – Oracle service name should be reachable from standby.

alter database recover logfile '/u01/app/oracle/fast_recovery_area/INDIA/archivelog/2014_02_06/o1_mf_1_159_9h522kw0_.arc'Thu Feb 06 00:25:17 2014Media Recovery Log /u01/app/oracle/fast_recovery_area/INDIA/archivelog/2014_02_06/o1_mf_1_159_9h522kw0_.arc

© 2014 Pythian30

What’s new in 12c Data Guard?1. Fast Sync2. Far Sync3. Real-time Cascade standby database4. SYSDG role5. Online standby data file movement 6. Recover standby database using

primary service7. DBMS_ROLLING

© 2014 Pythian31

DBMS_ROLLING• Rolling upgrade is an Active Data Guard feature • It is implemented using the new DBMS_ROLLING PL/SQL package• Data Guard Broker supported. • Upgrade process splits into leading group and trailing group, all other standbys in the

leading group can only be physical standbys.– LG database upgraded first.

CodeSQL> EXECUTE DBMS_ROLLING.INIT_PLAN (future_primary => ‘USA'); SQL> EXECUTE DBMS_ROLLING.BUILD_PLAN; SQL> EXECUTE DBMS_ROLLING.START_PLAN; SQL> EXECUTE DBMS_ROLLING.SWITCHOVER; Upgrade LG standby and bounce to RW mode from latest version, Perform Switchover.SQL> EXECUTE DBMS_ROLLING.FINISH_PLAN; Mount former primary CANADA using latest version including other standby database(s)

DATABASE_ROLE DB_UNIQUE_NAME Group

Primary CANADA Tail Group (TG)

Standby 1 INDIA Tail Group (TG)

Standby 2 USA Leading Group (LG)

Oracle12c data guard farsync and whats new

Documents

Transcript of Oracle12c data guard farsync and whats new