MirrorMode

The MirrorMode parameter determines whether to run the HPE DIH in mirror mode or non-mirror mode.

Set MirrorMode to True to run the HPE DIH in mirror mode.

In mirror mode the HPE DIH distributes all the index data it receives to all the IDOL servers that it is connected to. The IDOL servers are exact copies of each other and must all be configured in the same way.

Run the HPE DIH in mirror mode to ensure uninterrupted service if one of the IDOL servers fails. While one IDOL server is inoperable, data continues to be indexed into its identical copies which at the same time are still available to return data for queries.

The HPE DIH periodically checks if all the IDOL servers that it connects to are operating. If an IDOL server breaks down, the HPE DIH queues the data that this IDOL server normally receives, and after the IDOL server starts operating again, it indexes the queued data into it.

Set MirrorMode to False to run the HPE DIH in non-mirror mode.

In simple non-mirror mode the HPE DIH distributes the index data it receives evenly across the IDOL servers that it is connected to. For example, if the HPE DIH is connected to four IDOL servers, it indexes approximately one quarter of the data into each one of the IDOL servers (individual documents are not split up).

Run the HPE DIH in non-mirror mode if the amount of data that you want to index is too large for a single IDOL server. If the IDOL servers that the HPE DIH indexes into are situated on different machines, this option can also improve the indexing performance.

In non-mirror mode, you can also apply different distribution modes, such as DistributeByDate, DistributeByFields, DistributeByReference, DistributeOnBatch, and DistributeSendMinimal. These modes allow you to control how HPE DIH distributes the content between its child servers. For more information about these distribution modes, refer to the Distributed Index Handler Administration Guide and IDOL Expert.

NOTE:

You can use these distribution modes only when MirrorMode is set to False. HPE DIH will not start if you attempt to configure these distribution modes when MirrorMode is set to True.

The HPE DIH periodically checks if all the IDOL servers that it connects to are operating. How it behaves when a server goes offline depends on your distribution mode:

NOTE:

When you change the MirrorMode configuration option to enable or disable mirror mode, you must also delete the Main/ subdirectory inside the HPE DIH installation directory. This additional action prevents accidentally switching between mirror and non-mirror mode, which can cause a loss of data. If you do not delete the Main/ directory when changing this option, HPE DIH does not start.

Type: Boolean
Default: False
Required: No
Configuration Section: Server
Example: MirrorMode=False
See Also:  

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