What happens if Heartbeat is disabled in an NCache cluster?

If Heartbeat is disabled, the cluster loses its proactive fault detection mechanism. In the event of a silent network failure (like an unplugged cable or disabled NIC), peer nodes may fail to detect the disconnection immediately. This can delay the cluster view update, leading to temporary data inconsistencies or application request timeouts until a physical socket timeout occurs.

Is there a performance overhead when NCache Heartbeat is enabled?

There is zero performance overhead when the cluster is active. NCache only initiates heartbeat packets when nodes are idle. When nodes are actively exchanging data, the regular operational traffic serves as proof of life, making additional heartbeat packets unnecessary.

Should I enable Heartbeat on all topologies?

Yes, especially partitioned-replica and replicated topologies where node failure detection is critical. Less essential on single-node local caches.

Heartbeat for Cluster Connectivity

Communication between cluster nodes is fundamental to ensuring reliable cluster connectivity, high availability, and fault tolerance. To support this, NCache provides the Heartbeat mechanism that detects node failures and broken connections within a cluster. Connection breakage can occur due to hardware or network issues such as unplugged network cables, disabled NICs, firewall drops, or software defined network disruptions. When enabled, Heartbeat allows cluster nodes to periodically exchange dummy packets during idle periods to verify connectivity. Each node waits for acknowledgments from other nodes within a configured timeout interval. If a live node does not receive an acknowledgment from another node within this duration, the unresponsive node is considered dead and is excluded from the cluster through an updated cluster view. The Heartbeat mechanism incurs no performance overhead during active communication, as heartbeat messages are only sent when nodes are idle, making it well suited for production environments susceptible to transient network issues.

Using the NCache Management Center

Launch the NCache Management Center by browsing to http://localhost:8251 or <server-ip>:8251.
In the left navigation bar, click on Clustered Caches or Local Caches, based on the cache to configure.
Select the cache name, click on View Details.

Important

Ensure the cache is stopped before proceeding.

NCache Management Center showing the cache list with the selected cache's View Details option highlighted, indicating where to access detailed configuration settings for a clustered or local cache

This opens the detailed configuration page for the cache. Go to the Advanced Settings tab and click on Cluster Settings in the left bar.
Select the Use Heart Beat checkbox in Advanced Cluster Options to enable Heartbeat.

NCache Management Center Advanced Cluster Options screen displaying the Use Heart Beat checkbox enabled within Cluster Settings, used to configure heartbeat-based node connectivity monitoring.

Click on Save Changes at the end of the page to apply this configuration to the cache.

Manually Editing NCache Configuration

You can manually configure the NCache configuration file as explained below:

Important

Ensure the cache is stopped before making any configuration changes.

Enable/Disable Heartbeat through the config.ncconf file by specifying the use-heart-beat in the <cluster-settings> tag:

 <cache-settings ...>
   <cache-topology topology="partitioned-replica">
    <cluster-settings operation-timeout="60sec" stats-repl-interval="60sec" use-heart-beat="False">
      ...
     </cluster-settings>
   </cache-topology>
</cache-settings>

Once the changes are made, start the cache and restart the NCache Service.

Heartbeat for Cluster Connectivity

Using the NCache Management Center

Important

Manually Editing NCache Configuration

Important

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