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
HP NonStop RDF System Management Manual—524388-003
13-1
13 Network Transactions
The RDF/IMPX and RDF/ZLT products are able to guarantee backup database
consistency for transactions that update data residing on more than one RDF primary
system. RDF/IMPX and RDF/ZLT can map the volumes being protected to both the
MAT and auxiliary audit trails.
Without planning for network transaction support, the RDF product cannot guarantee
database consistency among the associated backup systems following the failure of
one of the primary systems.
Support for network transactions requires two major external changes.
1. If you have a distributed database spread over several RDF primary systems, you
must configure an RDF network wherein each primary system residing on its own,
mutually exclusive node has its own RDF subsystem that replicates its local data to
its own backup system. This is referred to as an RDF network because each RDF
subsystem knows the names of the systems protected by all other RDF
subsystems in the network. One, and only one, RDF subsystem within the network
is configured as the network master.
2. If you lose one or more RDF primary systems in the RDF network, you must
execute RDF takeover operations on all backup systems in the network.
For those primary systems still alive, you must first quiesce all application activity
(both local and remote) so that no further database updates are being performed,
and then bring down the communication lines between the primary and backup
systems before initiating the takeover.
With network transaction support, you must now be more careful when creating
Enscribe files that have alternate key files. Specifically, when you create an Enscribe
file with an altkey file you must ensure that both files reside on the same primary
system and that both are protected by the same RDF subsystem. If you do not do so,
then the updater responsible for creating the file on the backup system will not create
the file; rather, it will report an error 740 when it determines that the altkey file is not
protected by its RDF subsystem.
For RDF/ZLT configurations, all nodes that participate in a network transaction need to
be configured in the RDF network for RDF/ZLT protection.
Note. Network transaction processing is currently not supported in configurations that use the
triple contingency feature. You must use RDF/IMPX or RDF/ZLT to protect all databases open
to network transactions.