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
Introducing RDF
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RTD Warning Thresholds
RTD Warning Thresholds
RDF/IMP, IMPX, and ZLT allow you to designate a pair of RTD warning thresholds: one
for the extractor, and another for all of the updaters. Having set those thresholds, you
then can issue a STATUS RTDWARNING command with a designated repeat interval
to display information and statistics for only those processes (the extractor or any
updater) that have fallen behind the configured RTD threshold. For information about
setting the RTD threshold, see the SET RDF command description.
Process-Lockstep Operation
Process-lockstep operation, which is available with the RDF/IMPX and ZLT products,
prevents an application from executing further processing based on a committed
business transaction until all audit associated with that transaction is safely stored in
the image trails on the backup system.
This is accomplished by means of a new procedure, named DoLockstep, that you call
immediately after calling EndTransaction. With this lockstep protocol, the business
transaction is actually committed on the primary system prior to the start of the
DoLockstep operation, but the application is not allowed to continue processing until
DoLockstep has returned status to the application.
For information about this capability, see Section 14, Process-Lockstep Operation.
Support for Network Transactions
The RDF/IMPX and ZLT products support network transactions: transactions that
update data residing on more than one RDF primary system.
More specifically, the updates for a transaction on one of the two primary systems may
have been successfully transmitted and applied to the associated backup database,
but a disaster brought down the other primary system before the updates by the
transaction on that system could be sent to its backup database. After executing RDF
takeover operations on both backup systems, the data from the network transaction
would be present in one backup database but not in the one brought down by the
disaster. Thus the distributed backup database is inconsistent with regard to the
affected network transaction.
For information about this capability, see Section 13, Network Transactions.
RDF and NonStop SQL/MX
RDF can replicate NonStop SQL/MX user tables and indexes as well as NonStop
SQL/MP objects and Enscribe files.
For information about this capability, see Section 15, NonStop SQL/MX and RDF.