SQL Server Error Msg 41418 – This secondary replica is not connected to the primary replica

In this blog post, let’s learn about the error message “41418 – This secondary replica is not connected to the primary replica. The connected state is DISCONNECTED.” in Microsoft SQL Server, the reason why it appears and the solution to fix it.

SQL Server Error Message

41418 – This secondary replica is not connected to the primary replica. The connected state is DISCONNECTED.

Reason for the Error

SQL Server Error Msg 41418 is usually encountered when working with an Always On Availability Group configuration in SQL Server. This error indicates that a secondary replica in the Availability Group is not currently connected to the primary replica, and is in a disconnected state.

There can be several reasons for a secondary replica to be disconnected from the primary replica. Some of the common causes are:

1. Network connectivity issues: If there is a network disruption between the primary and secondary replicas, the secondary replica can become disconnected from the primary.
2. Availability group misconfiguration: If the Availability Group is not configured properly, or if the replica settings are incorrect, this can cause the secondary replica to become disconnected.
3. Replica synchronization issues: If the secondary replica falls behind in replication, it may become disconnected from the primary replica.

Solution

To resolve this error, you can try the following steps:

1. Verify network connectivity: Ensure that there are no network issues between the primary and secondary replicas, and that the secondary replica can communicate with the primary replica.
2. Check replica settings: Verify that the replica settings for the secondary replica are correct and match the settings for the primary replica. You can do this by comparing the settings using SQL Server Management Studio or T-SQL commands.
3. Check replication status: Verify that the replication status of the secondary replica is healthy and that it is keeping up with the primary replica. You can check this using SQL Server Management Studio or T-SQL commands.
4. Restart the secondary replica: If none of the above steps work, you can try restarting the secondary replica. This can sometimes resolve the issue and allow the replica to reconnect to the primary.

Here is an example of how to check the availability group status:

SELECT ag.name AS [Availability Group Name], ar.replica_server_name AS [Replica Server Name], ar.role_desc AS [Replica Role], ar.operational_state_desc AS [Replica State]
FROM sys.dm_hadr_availability_replica_states ar
INNER JOIN sys.availability_groups ag ON ar.group_id = ag.group_id;

This query will return information about the availability group, including the name of the group, the name of each replica, the role of each replica, and the operational state of each replica.