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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RDF and NonStop SQL/MX Operations
system \A keeping half of the table on system \A and moving the other half to a table
on system \X because RDF on system \X does not know about the shared access
NonStop SQL/MP DDL operation (the Stop-RDF-Updater audit records for the
operation on system /A go to system /B, not to system /Y).
Network Configurations and Shared Access NonStop
SQL/MP DDL Operations
Under certain circumstances, takeover network undo processing after having
performed a shared access NonStop SQL/MP DDL operation can lead to an abort with
database corruption.
You can, however, avoid that situation entirely by using the protocol described under
Network Configurations and Shared Access NonStop SQL/MP DDL Operations in
section 13 when performing shared access NonStop SQL/MP DDL operations in a
network environment:
RDF and NonStop SQL/MX Operations
For information about replicating NonStop SQL/MX objects, see Section 15, NonStop
SQL/MX and RDF.
Backing Up Image Trail Files
The RDF image trail files exist strictly for use by the receiver, purger, and updater
processes, and should not be explicitly opened by RDF users for any reason, including
backup to tape. Once the receiver has processed an image file, this file may no longer
serve a purpose (except in the case of triple contingency, where the file may be used
in a COPYAUDIT operation). In particular, image files are not like TMF audit dump
files; they cannot be used to restart RDF in the same way that audit files are used to
restart TMF. Typically, image files should only be accessed by RDF itself or by RDF
specialists and support people.
However, if you do wish to back up image trail files at your site, you should be aware of
the way RDF accesses these files and the ramifications of this access. When the
receiver updates an image trail file, it opens that file with shared read/write access.
When updaters read audit information from an image trail file and apply it to the backup
database, they open the image trail file with shared read-only access. When the RDF
purger process determines that a particular image trail file is no longer needed by any
updater, it purges that file unless the current RETAINCOUNT precludes doing so. If
you want to back up an image trail file, you should hold that file open to prevent the
purger from purging it until your backup is complete.