Oracle Active Data Guard: Best Practices and New Features Deep Dive
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This document outlines the best practices and new features of Oracle Active Data Guard, detailing its operational capabilities and enhancements aimed at improving data protection and availability. Key features include automatic block repair, real-time query capabilities, and streamlined management through the Data Guard Broker. It also discusses future developments and the importance of maintaining a robust architecture for disaster recovery and high availability in data management environments.
![SET FAST_START FAILOVER TARGET [NOWAIT]
Before Oracle Database 19c, The Observer moves to the next target
• Moving the target back to a previous standby requires disabling and enabling FSFO
Starting with Oracle Database 19c, users can execute the
SET FAST_START FAILOVER TARGET command
• Disabling and enabling FSFO will not be required
30 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public](https://image.slidesharecdn.com/adgbestpracticesandnewfeaturesdeepdivecollaborate2020-200617194310/85/Oracle-Active-Data-Guard-Best-Practices-and-New-Features-Deep-Dive-30-320.jpg)
Oracle Active Data Guard: Best Practices and New Features Deep Dive
- 1. Oracle Active Data Guard: Best Practices and New Features Deep Dive Glen Hawkins Senior Director of Product Management, Oracle MAA & Data Guard
- 2. The following is intended to outline our general product direction. It is intended for information purposes only, and may not be incorporated into any contract. It is not a commitment to deliver any material, code, or functionality, and should not be relied upon in making purchasing decisions. The development, release, timing, and pricing of any features or functionality described for Oracle’s products may change and remains at the sole discretion of Oracle Corporation. Statements in this presentation relating to Oracle’s future plans, expectations, beliefs, intentions and prospects are “forward-looking statements” and are subject to material risks and uncertainties. A detailed discussion of these factors and other risks that affect our business is contained in Oracle’s Securities and Exchange Commission (SEC) filings, including our most recent reports on Form 10-K and Form 10-Q under the heading “Risk Factors.” These filings are available on the SEC’s website or on Oracle’s website at http://www.oracle.com/investor. All information in this presentation is current as of September 2019 and Oracle undertakes no duty to update any statement in light of new information or future events. Safe Harbor 2 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 3. Topics (Active) Data Guard 19c Oracle (Active) Data Guard features What’s new and what you want to know from the past Data Guard Broker The way to manage your Data Guard implementation Features for the future What’s coming? Q & A 3 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 4. Align Oracle Capabilities with Customer Service Level Requirements Oracle MAA Reference Architectures Prod/Departmental Mission Critical Dev, Test, Prod Extreme Critical Single Instance with Restart Online Maintenance Validated Backup/Restore Silver + Physical Replication Comprehensive Data Protection Gold + Logical Active/Active Replication Advanced HA Options GOLD BRONZE SILVER PLATINUM Bronze + Database HA Active/Active Clustering Application Continuity 4 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 5. Oracle Maximum Availability Architecture (MAA) Reference Architectures Deployment Choices HA Features, Configurations & Operational Practices Customer Insights & Expert Recommendations Production Site Replicated Site Platinum Gold Silver Bronze Replication Data Protection Flashback RMAN + ZDLRA Continuous Availability Application Continuity Global Data Services Generic Systems Engineered Systems DBCS ExaCS/ExaCC Autonomous DB Active Replication Active Data Guard GoldenGate Scale Out RAC ShardingASM 5 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 6. Oracle (Active) Data Guard • Configurable Real-Time Query Apply Lag Limit • Integrated Support for Application Failover • SPA Support for Active Data Guard Environment • Support Up to 30 Standby Databases • Automatic Correction of Non- logged Blocks at a Data Guard Standby Database • RMAN recover standby simplification • Shadow Lost Write Protection • Active Data Guard Support for SQL Tuning Advisor • Synchronize Password Files Synchronization • Data Guard Broker PDB Migration or Failover • Multi-Instance Redo Apply • Oracle Data Guard Database Compare • Oracle Data Guard Support for Oracle Diagnostics Pack • Oracle Database In-Memory Support on Oracle Active Data Guard • Preserving Application Connections During Role Changes • Subset Standby • Active Data Guard Real-Time Cascade • Advanced Data Guard Broker Manageability • Separation of Duty Support • Protection During Database Rolling Upgrade • Fast Sync • Broker for Cascaded Standby Databases • Resumable Switchover Operations • Rolling Upgrade Using Active Data Guard • Single Command Role Transitions 11.2 12.1 12.2 18c 19c • Updates on ADG • Dynamically Fast-Start Failover (FSFO) target • Finer granularity Supplemental Logging • Flashback Standby database when Primary database is flashed back • IMCS on Multi-Instance Redo apply • Observe only mode for FSFO • Propagate Restore Points from Primary to Standby site • Simplified Database Parameter Management in a Broker Configuration Actively protecting data towards the future 6 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 7. (Active) Data Guard 7 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 8. Data Guard: Real-time Data Protection & Availability Primary Data Center DR Data Center Data Guard Broker (Enterprise Manager Cloud Control or DGMGRL) 8 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 9. Data Guard Protection Modes Balance Data Protection with Performance and Availability Mode Risk of data loss Transport If no acknowledgement from standby: Maximum Protection Zero Data Loss Double Failure Protection SYNC Stall primary until acknowledgement is received from replica Maximum Availability Zero Data Loss Single Failure Protection SYNC FASTSYNC Far Sync* Stall primary until acknowledgement is received or timeout threshold period expires – then resume processing Maximum Performance Potential for Minimal Data Loss ASYNC Primary never waits for standby acknowledgement 9 * Requires Active Data Guard License
- 10. Active Data Guard: Advanced Capabilities Zero data loss at any distance Automatic Block Repair Data Guard Broker (Enterprise Manager Cloud Control or DGMGRL) Offload Fast Incremental Backups & Rolling Upgrades Offload read- only workload to open standby database Primary Data Center DR Data Center 10 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 11. Active Data Guard: Advanced Capabilities Zero data loss at any distance Automatic Block Repair Data Guard Broker (Enterprise Manager Cloud Control or DGMGRL) DML Redirection Offload read- mostly workload to open standby database Primary Data Center DR Data Center Offload Fast Incremental Backups & Rolling Upgrades11 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 12. Note: A single DR copy may be multi- purposed for different combinations of the use cases described SYNC or ASYNC Active Data Guard Use Cases: Active Data Guard New DB Version Database Rolling Maintenance Primary copy Query & Report Offload open read-only Snapshot Standby Test Database single command refresh Offload RMAN Backups Disaster Recovery & HA manual or automatic failover Redo Far Sync, Recovery Appliance Source for thin snaps/clones Extract offload, Source for GoldenGate ALO mode 12 Primary copy Primary copy Primary copy Primary copy
- 13. Primary Database Far Sync Instance Active Standby Database• Oracle control file and log files • No database files • No media recovery • Offload transport compression • Supports up to thirty remote destinations • Zero data loss failover target • DR and reporting instance • Open read-only • Continuous Oracle validation • Manual or automatic failover SYNC Limited distance ASYNC Any distance transport compression over WAN Active Data Guard Far Sync Zero Data Loss Protection at Any Distance • Production copy Zero Data Loss Failover 13 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 14. Active Data Guard Automatic Block Repair • Oracle will detect if block is corrupt when read at primary • Corruption is automatically repaired using good copy from standby • In the same way – corruption detected at standby will also be repaired using good copy from primary Automatic block repair Primary Standby Active Data Guard Data Center 1 Data Center 2 14 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 15. New Automation makes it Simpler to Reduce Planned Downtime Active Data Guard Rolling Upgrades Start Switchover Finish DBMS_Rolling PL/SQL Package replaces all manual steps And that are really a lot of steps … 15 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 16. Transient logical standby DBMS_ROLLING has different phases, which you can access using the PL/SQL API. 1. Prerequisite Phase 2. init_plan 3. build_plan 4. start_plan 5. upgrade (or do what you want with the Transient logical standby) 6. switchover 7. Restart the standby 8. finish_plan Active Data Guard – DBMS_ROLLING DBMS_ROLLING has different ADVANTAGES Better support for Unsupported Data Types We block access to them Easier to use, less errors possible Scriptable due to PL/SQL Less downtime means more uptime! 16 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 17. (Active) Data Guard Features 19c • Tuning automatic outage resolution • Flashback database enhancements • Buffer Cache preservation after role transition • Improved Multi-Instance Redo Apply • Bigger Footprint of Active Data Guard Applications 17 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 18. Tunable Automatic Outage Resolution Data Guard maintains internal mechanisms that detect and correct issues with its redo transport and gap resolution processes • In case of network or disk I/O problems, these mechanisms prevent those processes from hanging and causing unnecessarily long gaps Use the following parameters to influence the outage resolution: • DATA_GUARD_MAX_IO_TIME - Sets the maximum number of seconds that can elapse before a process is considered hung while performing reads, writes, and status operations. • DATA_GUARD_MAX_LONGIO_TIME - Sets the maximum number of seconds as above, but for operations such as open and close 18 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 19. Flashback Technologies The “Rewind-Button” for the Database • Fast point-in-time recovery (PITR) without expensive restore operation • Error investigation • View data as of previous point in time • Error correction • Back-out a transaction • Incorrect table updates • Rewind the entire database • Integrated with other HA features: • Oracle Data Guard Copyright © 2019 Oracle and/or its affiliates. @T2 Col-1 Col-.. Col-n Row-1 tom 1234 vp Row-2 ben 8834 vp Row-3 charlie 9837 vp Row-n tom 8793 vp @T1 Col-1 Col-.. Col-n Row-1 abby 1234 officer Row-2 ben 8834 mgr Row-3 Charlie 9837 officer Row-n tom 8793 vp Wrong Update Flashback Table DB @ T1 DB @ T2 Flashback Database Wrong Update 19 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 20. Flashback Database Enhancements • Today, restore points are set on each Data Guard database individually • Requires multiple operations if the same restore point across the configuration is desired • With Oracle Database 19c, the primary restore points are automatically created on each standby • Identified by a suffix to the name of “_PRIMARY” Restore Points automatically propagate from the primary to the standbys 20 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 21. Flashback Database Enhancements • Today, after a flashback database and subsequent “resetlogs” operation has been performed on the primary, the standby database will follow the new incarnation, assuming the user first performs the same flashback operational configurations on the standbys. • With Oracle Database 19c, flashback operations are propagated to the standbys automatically • Requires that the standbys are configured for flashback database and in MOUNT state first • Standbys must have the same or larger setting for DB_FLASHBACK_RETENTION_TARGET Standbys automatically follow the primary after a RESETLOGS operation 21 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 22. Buffer Cache preservation after role transition The database buffer cache state is preserved on an ADG standby during a role change. Automatically enabled • Configure services so that users can stay connected on a service that is valid in both PHYSICAL_STANDBY and PRIMARY roles. Supported versions: • Oracle Database 18c – Single Instance • Oracle Database 19c – Oracle RAC Support Read/Write Read Read/Write Active Data Guard Standby PrimaryFailed Primary Primary 22 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 23. Improved Multi-Instance Redo Apply Supported versions: • Introduced with Oracle Database 12c Rel. 2 • Oracle Database 18c added support for Block Change Tracking enabled (ADG feature) • Oracle Database 19c supports the In Memory Column Store (IMCS) Parallel redo log apply on Oracle RAC standby 23 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 24. Bigger Footprint of ADG Applications DML Re-direction is automatically performed from an Active Data Guard standby to the primary without compromising ACID • New documented parameter ADG_REDIRECT_DML controls DML Redirection • New alter session ADG_REDIRECT_DML allows for per-session override • New ADG_REDIRECT_PLSQL commands Supported with Oracle Database 19c • Targeted for “Read-Mostly, Occasional Updates” applications DML on ADG 24 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 25. Active Data Guard DML on ADG 25 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 26. Data Guard Broker 26 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 27. Data Guard Broker Features for 19c • New TRACE_LEVEL qualifier replaces DEBUG • New commands to set database initialization parameters • Observe-only mode for Broker's Fast-Start Failover (FSFO) • Change Fast-Start Failover (FSFO) target • Show lag information for all configuration members • New Local Archiving properties • New commands to export and import a Broker configuration 27 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 28. SET TRACE_LEVEL USER|SUPPORT Replaces the DEBUG qualifier in Oracle Database 18c starting with 19c • More expandable in future, if new levels are necessary • ‘USER’ is the default SHOW ALL changes to display the TRACE_LEVEL instead of DEBUG DGMGRL> show all; trace_level USER echo OFF time OFF observerconfigfile = observer.ora 28 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 29. Oracle Data Guard broker properties, now map to Database Parameters: Set Database Initialization Parameters • ArchiveLagTarget (ARCHIVE_LAG_TARGET) • DataGuardSyncLatency (DATA_GUARD_SYNC_LATENCY) • LogArchiveMaxProcesses (LOG_ARCHIVE_MAX_PROCESSES) • LogArchiveMinSucceedDest (LOG_ARCHIVE_MIN_SUCCEED_DEST) • LogArchiveTrace (LOG_ARCHIVE_TRACE instance) • StandbyFileManagement (STANDBY_FILE_MANAGEMENT) • DbFileNameConvert (DB_FILE_NAME_CONVERT static) • LogArchiveFormat (LOG_ARCHIVE_FORMAT static, instance) • LogFileNameConvert (LOG_FILE_NAME_CONVERT static) • LsbyPreserveCommitOrder (PRESERVE_COMMIT_ORDER DBMS_LOGSTDBY package, static –> apply needs restart) • LsbyMaxEventsRecorded (MAX_EVENTS_RECORDED of DBMS_LOGSTDBY package) • LsbyMaxServers (MAX_SERVERS of DBMS_LOGSTDBY package, instance) • LsbyMaxSga (MAX_SGA of DBMS_LOGSTDBY package, instance) • LsbyRecordAppliedDdl (RECORD_APPLIED_DDL of DBMS_LOGSTDBY package) • LsbyRecordSkippedDdl (RECORD_SKIPPED_DDL of DBMS_LOGSTDBY package) • LsbyRecordSkipErrors (RECORD_SKIP_ERRORS of DBMS_LOGSTDBY package) 29 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 30. SET FAST_START FAILOVER TARGET [NOWAIT] Before Oracle Database 19c, The Observer moves to the next target • Moving the target back to a previous standby requires disabling and enabling FSFO Starting with Oracle Database 19c, users can execute the SET FAST_START FAILOVER TARGET command • Disabling and enabling FSFO will not be required 30 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 31. Fast-Start Failover (FSFO): Observe-Only Mode Test fast-start failover without impacting the production database • Determine when a failover or other interaction would have occurred during normal production processing • Discover what circumstances would cause an automatic failover to occur • Tune FSFO properties more precisely • Easier justify using Fast-Start Failover s to reduce the recovery time for failovers DGMGRL> ENABLE FAST_START FAILOVER OBSERVE ONLY; Enabled in Observe-Only mode. DGMGRL> 31 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 32. SHOW CONFIGURATION LAG Conveniently view lag information for all members: DGMGRL> SHOW CONFIGURATION LAG; Configuration – HA_Config Protection Mode: MaxPerformance Members: boston - Primary database chicago - Physical standby database Transport Lag: 0 seconds (computed 1 second ago) Apply Lag: 0 seconds (computed 1 second ago) newyork - Physical standby database Transport Lag: 0 seconds (computed 1 second ago) Apply Lag: 0 seconds (computed 1 second ago) Fast-Start Failover: DISABLED Configuration Status: SUCCESS 32 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 33. Export and Import the Broker Metadata File Users will be able to save a Broker readable copy of the configuration file Allows a lost Broker configuration to be rebuilt without having to have all individual commands used at the start and during configuration lifetime DGMGRL> EXPORT CONFIGURATION TO 'meta.xml' ; Succeeded. DGMGRL> DGMGRL> IMPORT CONFIGURATION FROM 'meta.xml' ; Succeeded. Run ENABLE CONFIGURATION to enable the imported configuration. DGMGRL> 33 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 34. Upcoming features: • Standby CDB continuity • Standardized Data Guard Broker Directory Structure • Data Guard broker Far Sync instance creation • Data Guard Broker Primary Database preparation • Fast Start Failover Configuration Validation • Fast Start Failover Failover Callouts • Fast Start Failover Lag Allowance in Max Availability Mode 34 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 35. Standby CDB continuity • In the past • A short hold on the remaining standby PDBs • In the future • When a PDB at Primary is cloned, PITR’ed, or when it undergoes flashback/open reset logs, ADG recovery and operations on remainder of the PDBs continues unabated • This helps to preserve the PDB isolation principle on ADG allowing us to maintain protection & query SLAs for remaining PDBs in exactly the same way as that on Primary for such operations. 35 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 36. Standby Result Cache The Result Cache state is preserved on an ADG standby during a role change. History • In the past • database buffer cache is preserved • In the future • Also result cache is preserved Facilitates using the Active Standby database for queries without performance impact. Read/Write Read Read/Write Active Data Guard Standby PrimaryFailed Primary Primary 36 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 37. Data Guard Broker Client Side Standardized Directory Structure $DG_ADMIN is defined by an environment variable $DG_ADMIN has the below subfolders • Admin • Config_<ConfigurationSimpleNameLog> • Dat • Log • Callout The Standardized Directory Structure helps : • to keep your environments clean • to keep your environments organized 37 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 38. Data Guard Broker Far Sync Instance Creation The Data Guard Broker interface has been extended with a command that enables users to create and add a Far Sync instance to a Data Guard Broker environment. Zero Data loss over long distance can be achieved by using the Data Guard Far Sync standby instances. To ease the setup and configuration of these instances the Oracle Data Guard Broker can now be used. This leads to easier and simplified setup which leverages the maintainability from the overall environment. 3838 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 39. Oracle Data Guard Broker Primary Database Preparation Using one single command in the Oracle Data Guard Broker, the database can be completely prepared for being a primary database. By using this feature the risk of human error on the future primary database is avoided. This can also be taken advantage of as the Data Guard Broker interface is scriptable, which leads to a more standardized environment by which complexity is removed and stability is increased. 3939 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 40. Fast Start Failover Configuration Validation FSFO Configuration Validation checks and reports misconfigurations of a FSFO enabled system. The command reports issues: • that can prevent enabling or initiating FSFO, e.g., the FSFO target is lagging. • that can affect what happens after FSFO, e.g., reinstatement. • about the FSFO parameters that are setup inappropriately, e.g., too low FSFO threshold for RAC databases. • on FSFO callout configuration files, e.g., inaccessible pre/post-callout scripts. 40 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 41. Fast Start Failover Failover Callouts When observer initiates a FSFO • it performs a pre-FSFO if the Fast-Start Failover configuration file exists • post-FSFO callout if the Fast-Start Failover configuration file exists A role transition often incorporates manual pre- and post steps to be performed. By automating these steps in callout scripts, human errors are avoided and a more consistent environment behavior is achieved. 41 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 42. Fast Start Failover Lag Allowance in Max Availability Mode Fast-Start Failover (FSFO) can be enabled to failover despite a lag in redo apply • using ASYNC apply • potentially data loss controlled by the FastStartFailoverLagLimit property • FSFO Lag Allowance in Max Availability Mode should be enabled if RTO objectives need to be met and the RPO expectation is preserved despite a well-defined data loss. • This is of particular use if the potential loss leads to faster recovery time when switching over to a standby database using ASYNC while an additional standby database in SYNC mode is configured. 42 Copyright © 2020, Oracle and/or its affiliates | Confidential: Public
- 43. Thank You Glen Hawkins Senior Director of Product Management, MAA & Data Guard Twitter @hawkinsg1 Blog https://blogs.oracle.com/maa LinkedIn https://www.linkedin.com/in/glenhawkins/