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
Preparing the RDF Environment
HP NonStop RDF System Management Manual—524388-003
2-9
Specifying System Generation Parameters for an
RDF Environment
Views on the Backup System
If an application uses any NonStop SQL/MP or NonStop SQL/MX shorthand or
protection views on a volume protected by RDF, audit data for transactions on the
views refers only to the underlying tables and not to the views. Views and their
underlying base tables must be present on the backup system after a takeover
operation so that applications can continue without interruption.
All base tables underlying the views must also reside on volumes protected by RDF on
the primary system.
Partitioned Tables and Files
If any partition of a partitioned NonStop SQL/MP or NonStop SQL/MX table or Enscribe
file exists on a volume protected by RDF, then all partitions for that file should be on
volumes protected by RDF. The partitions of a file protected by RDF can reside on
separate systems, and all of the systems should be protected by an RDF network.
Note that these are not absolute requirements, but if you lose your primary system and
must takeover on your backup system, you might not have access to the data that is
not protected by RDF.
Specifying System Generation Parameters for an RDF
Environment
When performing system generation, you should do as follows:
•
Use the PATHPACKETBYTES modifier to enable the Expand Variable Packetsize
feature so that Expand will send large packets.
•
Use the CONGCTRL modifier to enable Expand congestion control.
You might also want to enable the multipacket frame feature, depending upon the type
of traffic that will be passed over the Expand path.
For best results, consider using the RDF Professional Service to assist you in defining
the Expand requirements for your RDF environment. Contact your service provider for
further details.
Designing Transactions for RDF Protection
When designing applications containing transactions that update databases protected
by RDF, you must consider the following restrictions that apply to the subsystem:
•
The effects of network (distributed) transactions after an RDF takeover operation
•
Database operations not replicated by RDF
The subsections that follow explain these restrictions.