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Defining One or More Clusters
Create a cluster to organize Netscape Application Servers into data-synchronizing network-centric groups. For more information about clusters, see "What is a Cluster?"

Even though each Netscape Application Server can be mapped to only one cluster at a time, you can define as many clusters as you like. Some installations might define multiple clusters for testing purposes, for example.

And, while you can edit the Default cluster to easily set up your first cluster definition (see "Modifying the Default Cluster for Fast Cluster Set Up"), editing the Default cluster defines only one cluster. To get more than one definition, create the additional clusters.

To create a cluster, follow these steps.

  1. Stop the Netscape Application Server whose registry you will edit.

    2. Be aware that editing the server registry while the server is running can cause serious problems. Also, some changes take effect only after the engine is recycled.

  2. Open the registry editor.

    3. The registry editor displays the keys and values that apply to the Netscape Application Server. The appearance varies slightly between the UNIX and Windows NT systems.

  3. Open the Clusters folder in the registry.
HKEY_LOCAL_MACHINE\\SOFTWARE\\KIVA\\Enterprise\\2.0\\Clusters

As you proceed through each of the steps in this procedure, you can refer to the following figure that shows the kregedit display on a UNIX system for a cluster named "QA" that (so far) contains one Sync Server with a priority of zero.

  1. Ignore the SyncPersChunkSz key in the example.

    2. This key relates to an unsupported feature and is now ignored by the server. If this key is not present, don't worry—its presence is not necessary.

  2. Add the SyncTimerInterval key.

    3. This key specifies the intervals, in seconds, at which the synchronization service wakes up and checks to see whether any data has expired. Specifically, this key specifies how often the timer thread goes through the node list and removes all the nodes that have expired.

    If this value is too large, expired data will still be accessible. If this value is too small, the frequent waking up and checking can degrade system performance. The default value of 60 seconds is good for most clusters.

  3. Add a new, unique name for your cluster ("QA" in the example).

    4. Enter the value "0" (zero) in the Add Value pop-up window. This value is set purely for syntactical reasons, because the data type used for the name requires some value.

  4. Add the MaxBackups key.

    5. The maximum number of backup data synchronization servers determines how many Sync Backups are updated at the same time. For more information about Sync Backups, see "What is a Cluster?"

    Because all Sync Backups are updated at the same time, an extra load is created for each additional backup server. Consider the performance impact when you set the number of backups, and try to choose a number that is high enough to provide safety, while not so high as to negatively affect performance. The default value of 1 (one) is usually sufficient.

  5. Ignore the MaxHops key in the example.

    6. This key relates to an unsupported feature and is now ignored by the server. If this key is not present, don't worry—its presence is not necessary.

  6. Add the SyncServers key under the name of the cluster.

  7. Add each Sync Server to the cluster under SyncServers.

    8. The IP addresses and port numbers under the SyncServers key are the Executive Server processes of the data synchronization servers that belong to this cluster. Each server is listed by its host IP address:KXS port number=priority level.

    For a possibly helpful tip on finding the IP address and port number, see "IP Addresses Can Be Found in the SyncServers Key."

    1. Add the IP address and port number.

    2. Set the priority value.

    The priority setting for a data synchronization server determines which Sync Backup in a group of Sync Backups will become the replacement Sync Primary, and which Sync Alternate in a group of Sync Alternates will become the replacement Sync Backup.

    Priority settings start at zero, the highest priority setting. The lowest priority is 65,535. For more information about priority, see "How Sync Server Priority Affects a Cluster."

  8. Close the registry editor when you're finished.
After correctly completing these steps, you have defined a cluster. You can define as many clusters as you like, but you can map the synchronizer to only one cluster at a time. See the following section, Mapping the Synchronizer to the Cluster, for the procedure that enables communication.

 

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