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The Arbitration  parameter enables a choice of arbitration schemes, corresponding to one of 3 possible values for this parameter: 

• Default.  This enables arbitration to proceed normally, as determined by the ArbitrationRank settings for the management and API nodes. This is the default value. 

• Disabled.  Setting Arbitration = Disabled  in the [ndbd default]  section of the config.ini  file to accomplishes the same task as setting ArbitrationRank  to 0 on all management and API nodes. When Arbitration  is set in this way, any ArbitrationRank settings are ignored. 

• WaitExternal.  The Arbitration  parameter also makes it possible to configure arbitration in such a way that the cluster waits until after the time determined by ArbitrationTimeout  has passed for an external cluster manager application to perform arbitration instead of handling arbitration internally. This can be done by setting Arbitration = WaitExternal  in the [ndbd default]  section of the config.ini  file. For best results with the WaitExternal  setting, it is recommended that ArbitrationTimeout  be 2 times as long as the interval required by the external cluster manager to perform arbitration. 

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• RestartSubscriberConnectTimeout 

## Important 

This parameter should be used only in the [ndbd default]  section of the cluster configuration file. The behavior of the cluster is unspecified when Arbitration  is set to different values for individual data nodes. 

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This parameter determines the time that a data node waits for subscribing API nodes to connect. Once this timeout expires, any “missing”  API nodes are disconnected from the cluster. To disable this timeout, set RestartSubscriberConnectTimeout  to 0. 

While this parameter is specified in milliseconds, the timeout itself is resolved to the next-greatest whole second. 

Buffering and logging.  Several [ndbd]  configuration parameters enable the advanced user to have more control over the resources used by node processes and to adjust various buffer sizes at need. 

These buffers are used as front ends to the file system when writing log records to disk. If the node is running in diskless mode, these parameters can be set to their minimum values without penalty due to the fact that disk writes are “faked”  by the NDB  storage engine’s file system abstraction layer. 

• UndoIndexBuffer 

