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
Online Database Synchronization
HP NonStop RDF System Management Manual—524388-003
7-5
Considerations When Synchronizing Entire
Databases
reduce the number of image trails by stopping the RDF product and reconfiguring a
new RDF environment that has fewer image trails.
Alternatively, if your database is so big that it could take more time to load and prepare
than you have image space for, then you might want to synchronize one part of the
database at a time. When that operation has completed, you would then synchronize
the next portion. See below for the discussion on partial database synchronization and
the issues that pertain to it.
SYNCHDBTIME Issues
With the SYNCHDBTIME option in the INITIALIZE RDF command, there are three
special cases you might need to consider:
•
Enscribe create operations
•
NonStop SQL/MP Shared Access DDL operations
•
TMF shutdown operations
Enscribe Create Records
If you created the same Enscribe file on the primary and backup systems prior to
execution of the INITIALIZE RDF command, and if the extractor’s restart position is
located before the audit record for the create operation on the primary system, you
must remember to purge that file on the backup system. Otherwise, when the updater
tries to replicate the create operation, it will report a File System error 10 (File Already
Exists) and restart. It continues to restart and attempt to create the file until you purge
the existing file on the backup system.
Stop-RDF-Updater Records
Stop-RDF-Updater records in the MAT are associated with committed NonStop
SQL/MP DDL operations performed on the primary system with the WITH SHARED
ACCESS option. Although such operations can be performed on the primary system
without stopping your applications, they must be performed manually on the backup
system after all updaters have shut down in response to the same Stop-RDF-Updater
record.
As a general rule, you should not initialize the RDF subsystem to a synchdbtime if you
recently performed a NonStop SQL/MP operation with SHARED ACCESS on the
primary system. For example, suppose you have a NonStop SQL/MP table (tableA)
that contains the range of keys A through Z and you just moved its partition boundary
such that tableA now contains only the keys A through M and a new table (tableB)
contains the keys N through Z. Suppose also that you performed this operation
manually on the backup system.
If you then initialize the RDF subsystem to a point in the MAT prior to the Stop-RDF-
Updater record associated with the partition boundary change and an updater
encounters audit information associated a key N through Z, the updater will report an
error because it will try to apply the audit information to tableA (which used to contain