# DREREDISTRIBUTE

Allows you to redistribute the index when you update the number or weight of child servers.

This index action has an effect only when you have set UseConsistentHashing to `True` in the DIH configuration file. If UseConsistentHashing is set to `False`, DIH forwards the index action to all its child servers.

NOTE: This index action is only available for the DIH, and has no effect if you send it directly to IDOL Server.

In consistent hashing mode, all content is distributed in virtual nodes, which the DIH assigns to one or more child servers. When you run the `DREREDISTRIBUTE` index action, DIH checks whether the child server architecture has changed. If there is a change, DIH automatically exports and indexes the content in virtual nodes to redistribute your data evenly between the available child servers.

When you have configured at least one document replica in your system, you can also use `DREREDISTRIBUTE` to rebuild a child server that has become unavailable (for example because of a hardware failure). In this case, you can use the EngineManagement action to change the host and port of the child server, and then you can use `DREREDISTRIBUTE` with the RebuildEngine parameter to rebuild the child server from replicas.

DIH can process only one `DREREDISTRIBUTE` index action at the same time. If it starts to process a second `DREREDISTRIBUTE` index action in the queue before all child servers have finished redistributing the content, the second `DREREDISTRIBUTE` returns the `Unavailable` error code and does not run.

For more details about consistent hashing mode, refer to the DIH Administration Guide.

NOTE: For this index action, DIH uses the IndexUID parameter to identify the export index actions that it sends to its child servers, and the index actions to generate to index the redistributed data. If you do not specify an IndexUID, DIH generates one automatically to track the redistribution.

## Example

    http://12.3.4.56:9071/DREREDISTRIBUTE

## Optional Parameters

This action accepts the following optional parameters.

Parameter | Description
--- | ---
RebuildEngine | The IDs of child servers that you want to rebuild from replicas.

This index action accepts the following standard index action parameters.

Parameter | Description
--- | ---
IgnoreMaxPendingItems | Whether to ignore the IndexQueueMaxPendingItems limit for this index action.
IndexUID | An identification code for any document tracking events.
NoArchive | Turn off configured archiving for the index action.
Priority | The priority for the index job.

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