Release 10.1B: OpenEdge Replication
User Guide
Step 3: Entering pretransition
Replication attempts to recover from a failure; however, if it is unable to do so, all database activity can be failed over, or transitioned, to the secondary database and machine. The first task in readying the secondary database for transition is to apply all unapplied source database after-image extents, as shown in Figure 4–3.
Figure 4–3: Entering pretransition: applying all unapplied source database AI extents
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The application of the extents can be accomplished only if the secondary machine has access to these extents. For example, if the extents are stored on a storage area network (SAN) device, the secondary machine must have access to the device.
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To apply all unapplied source database after-image extents:
- Use the following command to determine the first after-image extent to apply:
The output from this command shows the source database after-image extent information.
- Beginning with the after-image extent listed, apply each source database after-image extent using the following command in succession until you have applied all of them:
If the source database after-image extents cannot be applied to the target database before transition, the target database will not contain any of the unapplied source database transactions. In this case, unless the transactions can be recreated and re-entered after transition, you will lose an indeterminate number of transactions.
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