By default index replication is deactivated. You can trigger replication in various ways. The table below gives an overview of the methods and of when you should use them.
Procedure | Effect | Use with | ||
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Indexing with QS* | Indexing without QS* | |||
1. |
Manual replication |
Index changes are available for searching when you have replicated the index. You use this method for the initial replication. |
! |
! |
2. |
Automatic replication following optimization in the queue server (Replicate after Optimize). |
Following the optimization of documents, index changes are available in the queue server for the search. |
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3. |
Automatic replication following every index update |
All index changes are available quickly for the search. |
! |
! |
4. |
Time-dependent replication using the queue server |
Index changes are available for searching when the next replication has taken place. Replication takes place regularly according to a defined schedule. |
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5. |
Time-dependent replication using the Python scheduler |
Index changes are available for searching when the next replication has taken place. Replication takes place regularly according to a defined schedule. |
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6. |
Replication triggering by the application using TREX |
TREX provides the (ABAP/Java) application with methods for triggering replication. |
! |
! |
*QS = queue server
The system replicates the entire index for the initial replication. In subsequent replications the system only replicates the changed index files. The duration of the replication and the generated system load depends on the following factors:
With decentralized data storage the replication generates a higher net load because the system has to copy the indexes to the slave hosts.
In order to determine the optimum time for replication, you have to weigh up the required topicality against the system load generated.
We recommend that you carry out the initial replication manually, since it can last a lot longer than subsequent replications.
If large indexes need to be replicated frequently, it may not be possible for the system to keep to your configured interval for replication. If this is the case, the system carries out automatic replication at the next possible point in time.
1. Replicating an Index Manually
2. Replicating the Index Automatically Following Optimization in the Queue Server (Replicate after Optimize).
Set the Replicate After Optimize queue parameter to On.
For more information on changing queue parameters, seeConfiguring Queue Parameters.
We recommend that you arrange for the index to be replicated automatically after every update - as described in point 3 - rather than using the Replicate After Optimize procedure. Replicate After Optimize only replicates changes involving the TREX queue server. Changes made without involving the queue server, such as changes to index properties and taxonomies, are not replicated.
3. Replicating an Index Automatically Immediately After Every Update
When you create an index, you can arrange for it to be replicated automatically immediately after every update. To do so, proceed as follows.
You can change this setting later on if you want.
This way of triggering index replication is particularly important in scenarios that do not use a TREX queue server.
4. Replicating the Delta Index Time-Dependently
Enter the time at which the replication is to take place in the Replication Time queue parameter.
Use All-3 to trigger replication every three hours. Use All (3:00) to trigger replication every morning at 3am.
For more information on changing queue parameters, seeConfiguring Queue Parameters.
5. Using the Python Scheduler to Schedule Index Replication
Change the following configuration files on all master name servers:
Configuration file | Change |
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TREXDaemon.ini |
If the Python scheduler is not yet active, activate it now: [daemon] programs=<other_sections>,cron |
crontab.ini |
Remove the comment sign from the following line: <scheduler> python replicate.py ‑‑silent ‑‑allIndexes=1 '' The default setting causes the system to check for changes to an index every 5 minutes. If there are no changes, the system takes no further action. If changes have taken place, they are replicated. Modify the schedule if necessary. For information on syntax and for examples, see the configuration file. |
Result
You can monitor index replication in the TREX admin tool (stand-alone) in the Index Landscape window. If necessary, you can terminate replications in progress there.