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
Process-Lockstep Operation
HP NonStop RDF System Management Manual—524388-003
14-4
The Lockstep Transaction
backup nodes should go down after the application has called DoLockstep, the
application will wait until the line comes back up and the lockstep audit data is safely
stored.
DoLockstep returns one of the following three states:
LockStepDone (value is 31428)
All audit data associated with the lockstep operation has been safely stored in the
image trail on the backup system.
LockStepDisabled (value is 31429)
Only returned when you have disabled lockstep processing. When this condition
code is returned to your application, what your application does next is up to you.
For example, you may choose to execute a recovery transaction that backs out the
work of the previous business transaction, or you may wish to continue as if the
lockstep operation has completed and rely on RDF to ship the audit data to the
backup system as soon as possible.
LockStepNotDone (value is 31426)
The RDF gateway process cannot be started. This status has the same
ramifications as LockstepDisabled, and what your application does next is your
decision.
The Lockstep Transaction
Remember, you must commit your business transaction before you call DoLockstep.
Thus, when the gateway process issues the lockstep transaction, all audit records
associated with your business transaction are guaranteed to be flushed in the audit
trail on the primary system before any lockstep audit is generated. Therefore, when
the lockstep audit is safely in the image trail on the backup system, you are also
guaranteed to have all audit information of your business transaction safely in the
image trail as well, because your business audit preceded the lockstep audit.
RDF Lockstep File
Each lockstep transaction involves a single update to a gateway-managed lockstep
file. This file is created by the lockstep gateway and it must only be updated by the
gateway. If you open the file and update data in it, you can potentially corrupt all future
lockstep operations.
When configuring the RDF configuration record, you must specify the name of the
volume on which you want the lockstep file to be located. This volume must be
configured to the Master Audit Trail (MAT), and either the entire volume or at least the
lockstep file must be protected by the RDF subsystem. You specify the volume by
issuing a SET RDF LOCKSTEPVOL command.