Using Oracle Data Guard for Applications Disaster Recovery

Using Oracle Data Guard for Applications Disaster Recovery … and More Jeff Slavitz Independent Consultant Oracle Applications DBA and Developer Jeff@Oracle. Apps. Pro. Com

What Would You Do? ? ? It’s Monday morning. Fatal production system hardware problem, or production hardware location is now a smoking hole Expect Production to be down for an unforseen amount of time It is year-end, you have a new manager and your senior DBA is on vacation Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

What is your backup situation? Do you have a cold backup? On-site or off-site? Do you have a hot backup. On disk? On tape? On another accessible site? How recent is it? Will you be able to read your tape backups? How recent are the archive logs that are now on the system that is down? Where are your archive log backups since the last hot backup? Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Options Restore and clone latest backup to a test box. How familiar is your DBA with RMAN recover? Is the box big enough to run the company? Will interfaces work (EDI, Payroll, …) Rent or buy a box. How long would it take to find and setup a new box? How long will it take to get the company up and running? Have you practiced this process or is this a fire drill? How many P 1 s will you need? How much data will the company lose? What does the company do while Oracle is down? Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

How Do You Feel? How Does Your Manager Feel? Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Or… In 15 minutes you’ve fully switched Oracle Applications over to a standby database You’ve tested the procedure with all DBAs The failover procedure is fully supported and documented by Oracle Interfaces are tested on the standby database You run the entire company once a month for a short period of time on the standby database You have a test standby database that DBAs practice on and you use for reporting purposes Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

How Do You Feel? How Does Your Manager Feel? Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

My Goal Today Tell you how you can be relaxed, not stressed, in a disaster recovery situation What is Data Guard Describe added value Data Guard and Flashback provide in addition to disaster recovery On a high level, review steps to implement Data Guard and Flashback Lessons learned - what Metalink notes don’t tell you Please ask questions as I go along Apologies to the non-DBAs Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

What is Data Guard? Data Guard is part of Oracle, not a separate product, which provides a set of services that create, maintain, manage, and monitor one or more standby databases Data Guard maintains these standby databases as transactionally consistent copies of the production database Data Guard can switch any standby database to the production role Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Without Data Guard Oracle® Data Guard Concepts and Administration 10 g Release 2 Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

With Data Guard Oracle® Database High Availability Best Practices 10 g Release 2 (10. 2) Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Why Not Use Data Guard? Too expensive – not! You already have and license it if you have Oracle Enterprise Edition. Nothing to purchase in order to implement what we discuss today. Too bleeding edge. Data Guard has been around since Oracle 9 i and Oracle 8 i as Standby Server. Too difficult to implement. Well documented by Oracle and completely supported. This presentation is a roadmap through the process plus my own observations and experiences. No DR box. Use test box for standby. Doesn’t protect against smoking hole but it’s better than nothing. How often do you really need DR? Is once enough? Plus a standby database can be used for other purposes. Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Why You Should Use Data Guard If your Production Oracle Applications instance went away would anybody notice? Our job is to protect the company’s data Your manager will thank you – DR is important. Data Guard plus Flashback provide added value: Instant clone Reporting instance Many exciting possibilities! Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

What Is Flashback? Introduced in Oracle 9 i Flashback is part of your Oracle database – no licensing requirement Provides a rewind button for your data Flashback Database - return database to a previous point in time Flashback Table - return a table to a previous point in time Flashback Query – see data at a previous point in time Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Data Guard and Flashback Together Many possibilities when used together … Scenario: Show stopper problem in Production Need to test a patch or data fix with current production data on test system ASAP Old school: Clone Time to complete: ? ? ? Hours Data Guard: Use standby database as an instant clone Time to complete: 10 minutes Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Instant Clone Activate standby database Perform testing on standby database When testing complete, flashback standby database to activation point in time Test again? Allows destructive testing. When all done, flashback and re-activate standby database Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Reporting Database Scenario: You want a data warehouse which is a snapshot of Production as of 9 pm the day before. Users need access via Oracle Applications and Discoverer Old School: Daily clone Data Guard: Use standby database as a reporting database Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Reporting Database Activate standby database Users login to standby database with Oracle Applications, Discoverer, or any other tool. Users can make changes in Application though they won’t be saved after Flashback. Archive logs accumulate on standby database At 9 pm each day flashback database to the way it was at 9 pm the day before, apply archive logs created since then, reopen database Can have multiple standby databases – one for DR, one for reporting, one for ? ? ? Oracle 11 i Active Data Guard allows read-only access to standby database while it is being updated from primary Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Bumps Along the Way Time implementation so it’s not at year-end Bumpy transition into production – low Test database activity is not an accurate picture of how Data Guard and Flashback will work in Production 3 mb network was not enough for standby to keep up with primary - needed 10 mb just for Data Guard Do periodic full company test of standby system Data Guard and Flashback implementation are well documented but there is a learning curve Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Implementing Data Guard and Flashback Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Hardware Configuration Primary (California) Standby (Nevada) Database 45 mb of which 8 -10 mb used by Data Guard Application Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3 Application

Software Configuration Database 10. 2. 0. 4 Data Guard Physical Bundle patch 7936993 Data Guard Logical Bundle patch 7937113 Data Guard Broker Bundle patch 7936793 Applications 11. 5. 10. 2 Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Data Guard Setup Two Metalink notes: Note 216212. 1: Business Continuity for Oracle Applications Release 11 i, Database Releases 9 i and 10 g Note 452056. 1: Business Continuity for Oracle Applications Release 12 on Database Release 10 g. R 2 (earned my vote for best Metalink note ever) Use Release 12 note Better configuration, simpler and works fine with 11 i Substitute APPL_TOP for Instance Top in text Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Logical vs Physical Two types of standby databases Physical Byte-for-byte duplicate of the primary database Archived redo logs transferred from primary database are directly applied to the standby database When standby in recovery mode it is mounted not open Logical Different structure than the primary database Oracle uses SQL statements to update standby Standby can be open while it is being updated Today we are talking about Physical standby databases Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Maximum Protection Mode Three types of protection – Maximum Protection is highest level of data security Primary database changes are not committed until it has been confirmed that the data is available on at least one standby database If Oracle determines that the redo data cannot be transferred from the primary server to the standby server, it will automatically stop the primary database instance Data transmitted synchronously - network implications Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Maximum Performance Mode Default protection mode The commit operation on the primary database is not contingent upon the data being received by the standby server If all of the standby servers become unavailable, processing will continue on the primary database Data transmitted asynchronously This performance mode is what are discussing today Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Maximum Availability Mode Second highest level of data security Primary database changes are not committed until it has been confirmed that the data is available on at least one standby database If the standby database becomes unavailable for any reason, the protection mode is temporarily lowered to maximum performance until the problem has been corrected Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Data Guard Installation Overview Develop a naming convention for your primary and standby database servers e. g. PROD_, PROD_ Create standby redo logs: one more than number of redo logs, same size as redo logs, do not multiplex Clone database to standby Copy datafiles to standby with closed database or with open database using RMAN (see note 753241. 1, Configuring Standby Database on R 12 using RMAN Hot Backup) Test primary and standby and listeners using tnsping Clone application to standby You are now ready to turn on Data Guard Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Primary init. ora ifile Parameters # Global unique name db_unique_name=PROD_CAMELDB 1 # Flash recovery area. This is the default location for control files, online # redo logs, archived redo logs, flashback logs, RMAN backups. db_recovery_file_dest=/u 01/oracle/flash_recovery_area # First destination for archived redo logs log_archive_dest_1 = 'LOCATION=USE_DB_RECOVERY_FILE_DEST MANDATORY‘ # Second destination for archived redo logs log_archive_dest_2 = 'SERVICE=PROD_LNXDRDB 1 valid_for=(online_logfiles, primary_role) db_unique_name=PROD_LNXDRDB 1 LGWR ASYNC=20480 OPTIONAL REOPEN=15 NET_TIMEOUT=30‘ Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Primary init. ora ifile Parameters # Limit on the total space available to the flash recovery area. db_recovery_file_dest_size=100 g # In minutes, how long you want to keep flashback files. Since using # guaranteed flashback really don't need this to be too big. db_flashback_retention_target=120 # On/Off switch for sending logs to standby system log_archive_dest_state_2 = defer # Databases in Data Guard configuration using my instance naming convention log_archive_config='dg_config=(PROD_CAMELDB 1, PROD_LNXDRDB 1)‘ # Log gap detection and resolution when this database is the standby fal_server = 'PROD_LNXDRDB 1‘ fal_client = 'PROD_CAMELDB 1' Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Start Data Guard Start primary and second database and listeners Primary: startup Standby: startup mount Turn on archive redo log transport on primary alter system set log_archive_dest_state_2=enable; Put standby in recovery mode Recover managed standby database using current logfile disconnect; Confirm logs are shipping to standby Primary: alter system archive log current; Standby: Check archive directory or query v$archive_log Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Care and Feeding of Data Guard Check alert log of primary and standby on a regular basis Set Enterprise Manager to email you when an error shows up in alert log Automatic archive log gap resolution usually works but network connectivity issue can require you to manually fix Primary alert log will notify you when a gap exists: FAL[client]: Failed to request gap sequence GAP - thread 1 sequence 435 -442 Copy missing archive logs from primary to standby On standby: alter database register logfile … Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Flashback db_recovery_file_dest defines Flash recovery area disk location This is the default location for control files, online redo logs, archived redo logs, flashback logs, RMAN backups Archive logs are placed in flashback area in sub-directory with date DO NOT delete files in flashback area manually; database calculates space available based on what RMAN has done db_recovery_file_dest_size Specifies limit on the total space to be used by the flash recovery area Check space usage using v$flash_recovery_area_usage When recovery area is full database stops! db_flashback_retention_target Defines in minutes, how long you want to keep flashback files Since using guaranteed flashback don't need this to be too big To turn flashback on: mount database and alter database flashback on Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Switchover – Database Steps Seamless switch from primary to standby Switch existing primary to new standby: Shutdown application Confirm all logs received and applied on standby alter database commit to switchover to standby with session shutdown; Recover managed standby database using current logfile disconnect Switch existing standby to new primary: alter database commit to switchover to primary; alter database open; alter system set log_archive_dest_state_2=enable; Confirm logs are shipping to standby by checking alert log, archive directory or query v$archive_log Training Day 2010 v 3 Jeff Slavitz - Nor. Cal OAUG

Switchover – Application Steps Some of these steps are not in Metalink note but are required Clear application context: exec fnd_conc_clone. setup_clean Run adautocfg on database and application tiers Run cmclean. sql (note 134007. 1) to avoid Output Post Processing manager not starting Update fnd_concurrent_requests Change logfile_name and outfile_name to new APPLCSF path Change logfile_node_name and outfile_node_name to new host name Update fnd_conc_req_outputs (for XML reports) Change file_name to new APPLCSF patch Change file_node_name to new host name Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Switchover – Application Steps Update wf_notification_attributes. text_value with new node name Update wf_item_attribute_values. text value with new node name Check for any other profile values that contain old node name Clear Apache cache Start application and send users new login url Synchronize APPLCSF log and out files Use rsync Faster than scp and only copies changed files rsync -avz $APPLCSF/out/${TWO_TASK}*/ applprod@lnxdrapp 1: $APPLCSF/out/${TWO_TASK}* Consider setting cron job to synchornize APPLCSF in case of system failure Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Failover Immediate switch of primary to standby system Some archive log data may be lost due to network latency On standby-soon-to-be-primary: Cancel database recovery alter database commit to switchover to primary Configure application as shown in Switchover Even with cron job synchronizing APPLCSF log and out files you probably won’t get all report output Repair former primary system Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Failover – Sync Old Primary as New Standby Establish new standby by copying primary datafiles using RMAN, cold backup or flashback. To use flashback: Find the SCN when the existing primary database became the primary: select to_char(standby_became_primary_scn) from v$database; On new standby: Startup mount flashback database to scn alter database convert to physical standby; recover managed standby database using current logfile disconnect; Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Instant Clone or Reporting Database On standby: Cancel standby recovery create restore point STBY_ON guarantee flashback database Active and open database Configure application as in Switchover Users can now login to the standby database through Oracle Applications, Discoverer or anything. Apply patches, test, update data in standby database. To revert to restore point STBY_ON and do further testing as needed: Shutdown immediate Startup mount Flashback database to guaranteed restore point STBY_ON Alter database open Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Resume Standby Operation On Standby: Shutdown application Shutdown database Startup mount Flashback database to restore point STBY_ON Alter database convert to physical standby Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Lessons Learned Script as much as possible – you will make typos under time pressure Use Enterprise Manager to see how Data Guard affects your system and tune accordingly Implement Data Guard and flashback at different times Setup one test database using Data Guard for testing and training Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

For the Future Try Maximum Availability protection Use Enterprise Manager to manage Data Guard. This requires Data Guard Broker implementation which requires use of spfile. Completely script switchover and failover as shown in note 452056. 1 Use RMAN to backup standby database only Upgrade database to 11 G and experiment with Active Data Guard. This allows you to create a read-only database that is open and is constantly updated from primary. Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

For More Information Google (it knows everything) http: //blogs. oracle. com/stevenchan Note 452056. 1 – Business Continuity for Oracle Apps Release 12 on Database 10 GR 2 (works fine for 11 i) Note 216212. 1 – Business Continuity for Oracle Apps Release 11 i, Database Releases 9 i and 10 G Note 753241. 1 – Configuring Standby Database on R 12 using RMAN Hot Backup (works fine for 11 i) Note 805438. 1 – How to Open Physical Standby For Read Write Testing and Flashback Data Guard Redo Transport & Network Best Practices Oracle 10 GR 2 White Paper Oracle Data Guard Concepts and Administration manual High Availability Best Practices manual Backup and Recovery Reference manual Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3

Questions? Want the latest version of this presentation? www. Oracle. Apps. Pro. com Jeff Slavitz Jeff@Oracle. Apps. Pro. com (415) 388 - 3003 Jeff Slavitz - Nor. Cal OAUG Training Day 2010 v 3