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
HP NonStop RDF System Management Manual—524388-003
1-15
Primary System Processes
Primary System Processes
On the primary system:
•
The monitor process coordinates subsystem starts and stops, some messages,
and NonStop SQL/MP and NonStop SQL/MX DDL operations using the WITH
SHARED ACCESS option on protected volumes, and monitors the other RDF
processes.
•
Each extractor process reads an audit trail (the MAT or a particular auxiliary audit
trail), filters out audit records not relevant to the backup database, and then
transmits the relevant audit records to an associated receiver process on the
backup system. Some control information for synchronizing the extractor and
receiver process pair is included each time the extractor process transmits the
audit records.
Backup System Processes
On the backup system:
•
There is one receiver process for each configured extractor process. A receiver
accepts the audit records from its extractor, sorts them, and then writes them to the
appropriate RDF image trail.
•
There is one updater process for each primary system volume being protected by
RDF. Updater processes read image records from their RDF image trails and pass
them to the disk process so that the disk process can perform the logical REDO
operations. The backup database is updated in cache each time the disk process
performs a logical REDO operation requested by an updater process.
•
The purger process interacts with the updaters to determine when image files can
be purged, and also determines which transactions updaters must undo for
takeover and stop-update-to-time operations.
RDF Operations
RDF can be run with updating of the backup database either enabled or disabled.
When updating is enabled, the RDF processes maintain a current, online copy of the
primary database on the backup system. By default, the subsystem starts with
updating enabled, and the RDF processes continue their updating activities until
updating is explicitly disabled or the subsystem is shut down.
When updating is disabled, the extractor process still transmits the TMF audit records
from the audit trails to the backup system, but no changes are applied to the backup
database. The receiver continues to collect audit records from the extractor and writes
these records to the image trails. However, the updater processes do not run while
updating is disabled.