Shutdown secondary sqlserver service; 2 nodes with Default Quorum (Node Majority) setup;

Cluster service, 2 nodes (SQL-A,SQL-B) with default Quorum (Node Majority) setup;
SQL Server AG group (alwaysonag) with 2 node (SQL-A, SQL-B)
Test shutdown secondary sqlserver service (SQL-B), will it affect primary replicas (SQL-A)



Shutdown SQL-B, SQLService to simulate SQL-B SQLServer fail

From SQL-A, sql-error log:
- A connection timeout has occurred on a previously established connection to availability replica 'SQL-B' with 'DAF385F5-FE27-4A48-A5DC-7E21214498C7].
Either a networking or a firewall issue exists or the availability replica has transitioned to the resolving role
- AlwaysOn Availability Groups connection with secondary database terminated for primary database 'testing' on the availability replica with Replica ID : {daf385f5-fe27-4a48-a5dc-7e21214498c7}

SQL-A database still ONLINE, from
AlwaysOn High Availability  --Availability Group -- AlwaysONAG --  Availability Replicas
we can see SQL-B replicas is down



SQL AG (alwaysonag) Dashboard



From Availability group state -- Critical --- Critical (1), Warning (3)


Some synchronous replicas are not synchronized
In this availability group, at least one synchronous replica is not currently synchronized. The replica synchronization state could be either SYNCHONIZING or NOT SYNCHRONIZING

Some availability replicas are not synchronizing data
In this availability group, at least one secondary replica has a NOT SYNCHRONIZING synchronization state and is not receiving data from the primary replica

Some availability replicas are disconnected
In this availability group, at least one secondary replica is not connected to the primary replica. The connected state is DISCONNECTED

Availability group is not ready for automatic failover
The availability group is not ready for automatic failover. The primary replica and a secondary replica are configured for automatic failover. however, the secondary replica is not ready for an automatic failover. Possibly the secondary replica is unavailable, or its data synchronization state is currently not in the SYNCHRONIZED synchronization state.

From Availability replica -- Critical (1), Warnings (1)



Start SQLService --SQL-B
From SQL-A, sql-error log:
A connection for availability group 'ALWAYSONAG' from availability replica 'SQL-A' with id [C8B53A5D-75CE-40CC-BB27-50CFBA48CB32] to 'SQL-B' with id [DAF385F5-FE27-4A48-A5DC-7E21214498C7] has been successfully established. This is an informational message only. No user action is required.

AlwaysOn Availability Groups connection with secondary database established for primary database 'testag' on the availability replica with Replica ID :{DAF385F5-FE27-4A48-A5DC-7E21214498C7}. This is an informational message only. No user action is required

AlwaysON Availability Groups connection with secondary database established for primary database 'testag' on the availability replica with Replica ID :{DAF385F5-FE27-4A48-A5DC-7E21214498C7}. This is an informational message only. No user action is required

SQL-B back online in availability Replicas


SQL AG (alwaysonag) dashboard