Configure Heartbeat and DNS Settings in a Multi-Site Failover Cluster

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Applies To: Windows Server 2008

In a multi-site cluster that has multiple subnets (not a VLAN), the amount of downtime that clients experience is dependent not just on how quickly failover occurs, but also on how quickly DNS replication occurs and how quickly the clients query for updated DNS information. To optimize the speed of failover and of DNS replication and querying for your networks, you can adjust heartbeat and DNS settings. For background information to help you decide whether you need to adjust these settings, see Requirements and Recommendations for a Multi-Site Failover Cluster (https://go.microsoft.com/fwlink/?LinkId=129109).

Important

If you are configuring a multi-site cluster that runs Microsoft® Office Exchange Server 2007, we recommend you review this topic but also use the instructions at https://go.microsoft.com/fwlink/?LinkId=128166, which are specific for Office Exchange Server 2007.

Membership in the local Administrators group, or equivalent, is the minimum required to complete this procedure. Review details about using the appropriate accounts and group memberships at Local and Domain Default Groups (https://go.microsoft.com/fwlink/?LinkId=83477).

To configure heartbeat and DNS settings in a multi-site failover cluster

  1. On a node in the cluster, open a Command Prompt window.

  2. Determine whether to change the heartbeat settings, for nodes on a common subnet, nodes communicating across subnets, or both. For background information about heartbeat settings, see Requirements and Recommendations for a Multi-Site Failover Cluster (https://go.microsoft.com/fwlink/?LinkId=129109).

    By default, regardless of subnet configuration, heartbeat frequency (also known as subnet delay) is once every second (1000 milliseconds). The range for heartbeat frequency is once every 250-2000 milliseconds on a common subnet, and 250-4000 milliseconds across subnets. By default, when a node misses a series of 5 heartbeats, another node will initiate failover, and the range for this value (also known as subnet threshold) is from 3 through 10.

  3. If in step 2 you decided to change the heartbeat settings, run one or more of the following commands. Note that the first two commands affect nodes on a common subnet and the second two commands affect communication across subnets:

    cluster /cluster:<ClusterName> /prop SameSubnetDelay=<value>

    cluster /cluster:<ClusterName> /prop SameSubnetThreshold=<value>

    cluster /cluster:<ClusterName> /prop CrossSubnetDelay=<value>

    cluster /cluster:<ClusterName> /prop CrossSubnetThreshold=<value>

  4. To confirm that the heartbeat settings are set as intended, run the following command:

    cluster /cluster:<ClusterName> /prop

  5. View the network names of resources that are currently configured on the cluster by running the following command:

    cluster /cluster:<ClusterName> res

  6. Determine which IP addresses should be registered in DNS for your cluster: either all IP addresses on which a network name resource depends, or only the IP address that successfully comes online (that is, the IP address on the subnet of the node that currently owns that network name resource). For background information about this setting, see Requirements and Recommendations for a Multi-Site Failover Cluster (https://go.microsoft.com/fwlink/?LinkId=129109).

    The default is to register only the IP address that successfully comes online.

  7. Choose and run only one of the following commands, substituting the name of the resource for <NetworkNameResource>:

    • To cause all IP addresses on which a network name resource depends to be registered, run the following command:

      cluster /cluster:<ClusterName> res <NetworkNameResource> /priv RegisterAllProvidersIP=1

    • To cause only the IP address that successfully comes online to be registered, run the following command:

      cluster /cluster:<ClusterName> res <NetworkNameResource> /priv RegisterAllProvidersIP=0

  8. Determine the value to use for the DNS setting called Time to Live (TTL). As an example, the value recommended for Office Exchange Server 2007 is five minutes, which equals 300 seconds. If you do not adjust the TTL value, it defaults to 20 minutes (1200 seconds). For background information about TTL, see Requirements and Recommendations for a Multi-Site Failover Cluster (https://go.microsoft.com/fwlink/?LinkId=129109).

  9. To change the TTL setting, run the following command:

    cluster /cluster:<ClusterName> res <NetworkNameResource> /priv HostRecordTTL=<TimeInSeconds>

    where <NetworkNameResource> is the name of the clustered resource that you want to set the TTL value for, and <TimeInSeconds> is the value you want to set for TTL.

  10. To confirm that all the DNS settings are set as intended for a given network name resource, run the following command:

    cluster /cluster:<ClusterName> res <NetworkNameResource> /priv

  11. Take the clustered service or application offline and bring it back online, using the method that you are most familiar with. For example, to use the Failover Cluster Management snap-in, under Services and Applications, right-click the service or application and click Take this service or application offline, then right-click again and click Bring this service or application online.

Additional references