What is a recommended value for NCache Connection Retries?

The default value is 2 for cluster connectivity. In higher-latency or less reliable networks, you may increase it to allow more time for transient failures to recover.

How do Connection Retries interact with the Retry Interval?

These settings work together to define the recovery window. After a failed attempt to connect to all servers, the node waits for the 'Retry Interval' duration before starting the next retry cycle.

Why must I stop the NCache cache before changing retry settings?

Stop the cache before changing cluster settings to ensure the updated configuration is applied consistently across the cluster.

Do these settings also apply to NCache client applications?

No. This specific setting is for inter-node (server-to-server) cluster connectivity. Client-to-server reconnection is configured separately within the client.ncconf file or programmatically via CacheConnectionOptions in your application code.

What happens when NCache exhausts all connection retries?

Once retries are exhausted, the node considers the peer dead and excludes it from the cluster topology. This may trigger automatic data rebalancing or state transfer to ensure the remaining nodes maintain the specified replication level.

Connection Retries

Nodes participating in a cluster are connected with each other through TCP connections, which may break due to network failures or infrastructure issues. In such cases, a node attempts to re-establish connectivity by scanning the configured server list once per attempt. If no connection is restored, it waits for the configured Retry Interval and then repeats the scan until the configured retry limit is reached. Connection Retries specifies the maximum number of reconnection attempts before a node marks a connection as unavailable, helping prevent premature node isolation and improve cluster stability. These settings can be changed in the following ways.

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.
Against the cache name, click on View Details.

NCache Management Center showing the list of caches with the "View Details" option highlighted for a running cache.

This opens up the detailed configuration page for the cache. Go to the Advanced Settings tab and click on Cluster Settings in the left bar.
Set the Connection Retries present in the Advanced Cluster Options section, as per your requirement.

Advanced Cluster Options in NCache Management Center displaying the Connection Retries setting under Cluster Settings.

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

Manually Editing NCache Configuration

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

Important

Ensure the cache is stopped before making any configuration changes.

Specify the Connection Retries count through config.ncconf by specifying the connection-retries in the <cluster-connection-settings> tag:

<cluster-settings ...>
  <cluster-connection-settings cluster-port="7804" port-range="2" connection-retries="2" .../>
</cluster-settings>

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

Connection Retries

Using the NCache Management Center

Manually Editing NCache Configuration

Important

See Also

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