Always On AG- Readable Secondaries: How they work?

Readable Secondary AG databases internally use snapshot isolation under the covers. This will enable read-only workload to run against secondary databases.


How to configure MSDTC as Clustered service (Windows 2008+)

How many IP addresses are required for 2 node active-passive SQL Server failover cluster instance?

Total : 6 – 7

1 for WSFC cluster network name

1 for SQL Server instance network name

2 (1 on each node) for private/internal/heartbeat network among cluster nodes

2 (1 on each node) for public network access

1 for MSDTC (if MSDTC is configured as clustered service)

2 (1 for each node) for iSCSI HBA/network adapter for communication to SAN (if iSCSI SAN is used). 

HBA is used for offloading iSCSI TCP/IP traffic processing from CPU