Release 10.1B: OpenEdge Replication
User Guide


Manually applying after-image extents

During normal conditions, the target database is automatically updated with data from the source database. The updates are transmitted as blocks of data from the source’s AI transaction log. After a failure condition, it is possible that the most recent blocks were not able to reach the target. For example, a TCP/IP failure could lose packets that were waiting for transmission.

You can recover the missing data by manually applying the after-image extents that contain the data that has not already been applied to the target. However, you can do so only under the following conditions:

To apply AI extents:

  1. Display failure recovery information using the following command:
  2. dsrutil target-db-name -C RECOVERY Agent 
    

  3. Determine the AI extent number from the command output. Select the last-applied AI extent or, if the last-applied extent was completely processed, select the next available extent.
  4. The following shows an example of the relevant section of the command output:

                                  . 
                                  . 
                                  . 
      Last AI Extent processed 
       AIMAGE BEGIN date:              Tue Oct 18 13:33:31 2005 
       AIMAGE NEW date:                Tue Oct 18 13:48:55 2005 
       After Image File Number:        3 
       File Last Opened:               Tue Oct 18 13:48:55 2005 
       Completely Applied to Target:    No 
    

    Determine the file number of the last-applied AI extent. In this example the last-applied extent is 3. Since the value after Completely Applied to Target is No, you will use 3 as the extent-name in Step 3.

    If the value after Completely Applied to Target is Yes, you would use 4 as the extent-name in Step 3, since extent 3 is already completely applied.

  5. Use the appropriate AI extent file number in the following command:
  6. dsrutil target-db-name -C ApplyExtent extent-name 
    

    As the command executes, it performs the following validation:

    • The extent must exist and be valid.
    • The status of the extent must be FULL, BUSY, or LOCKED.
    • The AI extent file number either must be the same as the AI extent file number for the last AI block processed by the agent, or it must be the next extent file number (if the previous AI extent was completely processed).

After you apply the AI extent, you can begin a manual transition of the target. For more information, see the "Setting up manual transition" section.


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