it's quite usual, that the DB servers are protected from access from the internet, and if your hadoop cluster is not in the company network, it is considered as being internet, so you security team will not allow access. You can discuss with your networks security team, if a VPN tunnel from your hadoop cluster to the sql server is possible, but in most cases, network security will require in that cases to apply all internal security standards on your hadoop cluster as well, as otherwise they are not considered as trustworthy. Another option is, if a SSH connection is allowed from the ms SQL server to your hadoop cluster, in that case you could tunnel the port 1433 as well to use it from hadoop. A common solution to this situation is also to migrate the hadoop cluster from a cloud location to a on premise installation. ... View more

@Kumar Veerappan Unfortunately YES your cluster won't function you will have to shutdown gracefully your cluster and wait for the patching to end. In an HDP HA setup the master nodes NN, RM should be on 2 distinct racks/switches Here are some considerations Machines should be on an isolated network from the rest of the data center. This means that no other applications or nodes should share network I/O with the Hadoop infrastructure. This is recommended as Hadoop is I/O intensive, and all other interference should be removed for a performant cluster. Machines should have static IPs. This will enable stability in the network configuration. If the network were configured with dynamic IPs, on a machine reboot or if the DNS lease were to expire then the machine’s IP address would change, and this would cause the Hadoop services to malfunction. Reverse DNS should be set up. Reverse DNS ensures that a node’s hostname can be looked up through the IP address. Certain Hadoop functionalities utilize and require reverse DNS. Dedicated “Top of Rack” (TOR) switches to Hadoop Use dedicated core switching blades or switches Ensure application servers are “close” to Hadoop Consider Ethernet bonding for increased capacity All clients and cluster nodes require Network access and open firewall ports each of the services for communication between the servers. If deployed to a cloud environment, then make certain all Hadoop cluster Master and Data nodes are on the same network zone (this is especially important when utilizing cloud services such as AWS and Azure). If deployed to a physical environment, then make certain to place the cluster on in a VLAN. The Data node and Client nodes should at the minimum have a 2 x 1 Gb Ethernet a typically recommended Network controller is 1 x 10 Gb Ethernet. For the switch communicating between the racks, you will want to establish the fastest Ethernet connections possible with the most capacity. Hope that helps ... View more

Fount out that this is available in zkfc logs which will be present in the name node. For some reason these logs are not present in my name node boxes, so probably I need to restart the ZKFC services. Thanks Kumar ... View more