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 Takeover Processing
Transactions that must be undone during this undo pass are stored in the ZFILUNDO
file in the Master Image Trail subvolume.
Phase Three Undo Pass
This is also known as Network Undo. If you are running in an RDF network and you
lose one or more primary systems, you must do a takeover on all backup systems in
your RDF network. For a complete description of the takeover operation in an RDF
network, see RDF Takeovers Within a Network Environment in section 13.
Transactions that must be undone during this undo pass are stored in the ZNETUNDO
file in the Master Image Trail subvolume.
When the takeover operation completes, your backup database is in a consistent and
stable state with regard to transactions that committed on your primary system.
Preparing for Takeover Processing
Before you issue a TAKEOVER command from the backup system, you need to
specify the name of the control subvolume in the command that starts your RDFCOM
session:
>RDFCOM control-subvol
Issuing the TAKEOVER Command
To request the takeover operation, enter the TAKEOVER command as follows:
]TAKEOVER
If the communications lines are up and the monitor and extractor are still running on
the primary system when you issue the TAKEOVER command, RDF rejects this
command.
If the communication lines are down or the monitor and extractor have failed when you
issue the TAKEOVER command, RDF executes the command, as follows on the
backup system:
•
If RDF is running with updating on, RDFCOM sends a takeover message to the
receiver and all updater processes.
•
If RDF is running with updating off, RDFCOM stops the receiver process and starts
the monitor in takeover mode. The monitor then starts a receiver process and all
updater processes. (The name of this monitor on the backup system is generated
by the system.)
•
If RDF had been stopped, RDFCOM starts the monitor in TAKEOVER mode. The
monitor starts a receiver process and all updater processes. (The name of this
monitor is generated by the system.)
If a monitor process was started on the backup system, the monitor stops after the
other RDF processes are shut down.