Configure the Global Update Manager (GUM) mode in WFC

All (write) and Local (read).

  1. 0 All nodes in the cluster receive and process an update before the cluster commits the change to the database. {Sync Mode}
  2. Cluster database is always consistent as it is only updated after all nodes have processed the update.
  3. Database reads occur locally on the node.

Majority (read and write)

  • 1 Only a majority of nodes in the cluster must process an update before it is then committed to the cluster database.{Async Mode}
  • For a database read, the cluster compares the latest time stamp from a majority of the running nodes, and uses the data with the latest time stamp.

The issue with this option is that when requests for information are made against a node in the cluster {{DatabaseReadWriteMode=1}}, the node has to communicate with a majority number of nodes in the cluster, to get confirmation, before it can send a response to the request. For adhoc requests, this is fine, however when requests are constantly being put the cluster, this puts a massive communication load on the cluster and causes CPU overhead.

Default Behaviours
 
{{Windows Server 2012 R2}}
Get-Cluster | fl DatabaseReadWriteMode
DatabaseReadWriteMode : 1

{{Windows Server 2016}}
Get-Cluster | fl DatabaseReadWriteMode
DatabaseReadWriteMode : 0

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