RDF System Management Manual
Table Of Contents
- RDF System Management Manual
- What’s New in This Manual
- About This Manual
- 1 Introducing RDF
- RDF Subsystem Overview
- RDF Processes
- RDF Operations
- Reciprocal and Chain Replication
- Available Types of Replication to Multiple Backup Systems
- Triple Contingency
- Loopback Configuration (Single System)
- Online Product Initialization
- Online Database Synchronization
- Online Dumps
- Subvolume- and File-Level Replication
- Shared Access DDL Operations
- EMS Support
- SMF Support
- RTD Warning Thresholds
- Process-Lockstep Operation
- Support for Network Transactions
- RDF and NonStop SQL/MX
- Zero Lost Transactions (ZLT)
- Monitoring RDF Entities With ASAP
- 2 Preparing the RDF Environment
- 3 Installing and Configuring RDF
- 4 Operating and Monitoring RDF
- 5 Managing RDF
- Recovering From File System Errors
- Handling Disk Space Problems
- Responding to Operational Failures
- Stopping RDF
- Restarting RDF
- Carrying Out a Planned Switchover
- Takeover Operations
- Reading the Backup Database
- Access to Backup Databases in a Consistent State
- RDF and NonStop SQL/MP DDL Operations
- RDF and NonStop SQL/MX Operations
- Backing Up Image Trail Files
- Making Online Dumps With Updaters Running
- Doing FUP RELOAD Operations With Updaters Running
- Exception File Optimization
- Switching Disks on Updater UPDATEVOLUMES
- 6 Maintaining the Databases
- 7 Online Database Synchronization
- 8 Entering RDFCOM Commands
- 9 Entering RDFSCAN Commands
- 10 Triple Contingency
- 11 Subvolume- and File-Level Replication
- 12 Auxiliary Audit Trails
- 13 Network Transactions
- Configuration Changes
- RDF Network Control Files
- Normal RDF Processing Within a Network Environment
- RDF Takeovers Within a Network Environment
- Takeover Phase 1 – Local Undo
- Takeover Phase 2 – File Undo
- Takeover Phase 3 – Network Undo
- Takeover Phase 3 Performance
- Communication Failures During Phase 3 Takeover Processing
- Takeover Delays and Purger Restarts
- Takeover Restartability
- Takeover and File Recovery
- The Effects of Undoing Network Transactions
- Takeover and the RETAINCOUNT Value
- Network Configurations and Shared Access NonStop SQL/MP DDL Operations
- Network Validation and Considerations
- RDF Re-Initialization in a Network Environment
- RDF Networks and ABORT or STOP RDF Operations
- RDF Networks and Stop-Update-to-Time Operations
- Sample Configurations
- RDFCOM STATUS Display
- 14 Process-Lockstep Operation
- Starting a Lockstep Operation
- The DoLockstep Procedure
- The Lockstep Transaction
- RDF Lockstep File
- Multiple Concurrent Lockstep Operations
- The Lockstep Gateway Process
- Disabling Lockstep
- Reenabling Lockstep
- Lockstep Performance Ramifications
- Lockstep and Auxiliary Audit Trails
- Lockstep and Network Transactions
- Lockstep Operation Event Messages
- 15 NonStop SQL/MX and RDF
- Including and Excluding SQL/MX Objects
- Obtaining ANSI Object Names From Updater Event Messages
- Creating NonStop SQL/MX Primary and Backup Databases from Scratch
- Creating a NonStop SQL/MX Backup Database From an Existing Primary Database
- Online Database Synchronization With NonStop SQL/MX Objects
- Offline Synchronization for a Single Partition
- Online Synchronization for a Single Partition
- Correcting Incorrect NonStop SQL/MX Name Mapping
- Consideration for Creating Backup Tables
- Restoring to a Specific Location
- Comparing NonStop SQL/MX Tables
- 16 Zero Lost Transactions (ZLT)
- A RDF Command Summary
- B Additional Reference Information
- C Messages
- D Operational Limits
- E Using ASAP
- Index
Managing RDF
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Preparing for Application Processing on the Backup
System
Preparing for Application Processing on the Backup System
See Tips for Executing Fast Business Takeover Operations in section 1 for information
on how you can execute an RDF takeover and resume business activities on your
backup system in the shortest amount of time.
Before application processing starts on the backup system following a successful
takeover operation, you might need to update statistics for NonStop SQL/MP database
tables and recompile NonStop SQL/MP program files.
After a takeover operation occurs, the following considerations apply to NonStop
SQL/MP tables protected by RDF:
•
Three other operations might help maintain acceptable performance for the
applications:
•
Evaluate whether to perform an update statistics operation on database tables.
•
Evaluate whether to recompile the application programs with the NonStop
SQL/MP compiler.
•
Use the CHECK INOPERABLE PLANS NonStop SQL/MP compiler option for
any necessary recompilations.
Before operations that would cause automatic NonStop SQL/MP compilation, you can
recompile NonStop SQL/MP program files to check for compilation errors before
running the programs. For a complete description of operations that invalidate
application programs, causing automatic NonStop SQL/MP compilation, see the HP
NonStop SQL/MP Installation and Management Guide.
Restoring the Primary System
When the failed primary system is restored to operable condition you have two
methods of resynchronizing your primary database with your backup database where
your applications are now running. One method is online, and the other is offline.
Online Method of Resynchronizing the Primary Database
When an RDF takeover operation completes, the purger process logs the RDF event
888, which specifies a Master Audit Trail position. On your primary system, you can
then execute TMF File Recovery with the TOMATPOSITION option. This option
requires a MAT position, and you use the position in the RDF Event 888. When File
Recovery completes, the database on your primary system is in the exact same state
as the database on your backup system was when the RDF takeover operation
completed.
Note. If you are using the triple contingency feature, you must issue a COPYAUDIT command
after the takeover operations are complete to copy missing audit from the backup system that
has the most to the one that has the least. See Section 10, Triple Contingency for details about
this situation.