Which three are characteristics of leaf nodes in an Oracle Clusterware 12c Flex Cluster? (Choose three.)
A.
They can be on a different subnet to the hub nodes.
B.
Grid Naming Service (GNS) must exist on one of the leaf nodes.
C.
They discover hub nodes automatically at startup.
D.
They require direct access to shared storage.
E.
They may discover hub nodes without having the DNS delegation configured by network.
F.
Oracle database 12c RAC instances may not run on leaf nodes.
one exam engine says: DEF , but I think the rigth ones are:
C,E, F
D is not rigth in my opinion: Leaf nodes does not required direct access to shared storage, the hub nodes yes
Compared to Hub Nodes, Leaf Nodes are loosely coupled to the cluster. When Oracle Clusterware is started on a Leaf Node, the Leaf Node automatically discovers the Hub Nodes and is associated with a single Hub Node. (C)
For cluster membership purposes, Hub Nodes periodically exchange heartbeat messages with their associated Leaf Nodes. Similar mechanisms are used for other services
In any case, if there is no fault with the Leaf Node, it can be brought back into the cluster by restarting Oracle Clusterware on the
Leaf Node.
A Leaf Node does not require direct access to shared storage. (NOT D)
This means that Leaf Nodes can participate in the cluster without storage-related hardware and network connections, such
as fiber-channel network connections and host bus adapters.
In release 12.1, all Leaf Nodes are on the same public and private networks as the Hub Nodes. (NOT A)
Flex Clusters require the Grid Naming Service (GNS) to be configured with a fixed virtual IP (VIP) on one of the Hub Nodes. (NOT B)
Correct: C, E, F
it could be, I think you are right with B there is not a requirement that GNS must exist on one leaf node…
Agree with you!
Correct: C,E,F
Correct should be B,C,E
A wrong
B correct
Network Requirements for Oracle Flex Cluster Configuration
You must use Grid Naming Service (GNS) with an Oracle Flex Cluster deployment.
C: correct
D wrong
Leaf Node
Servers that are loosely coupled with Hub Nodes, which may not have direct access to the shared storage.
E correct
F wrong
Oracle RAC database instances running on Leaf Nodes are referred to as far Oracle ASM client instances. Oracle ASM metadata is never sent to the far client database instance. Instead, the far Oracle ASM client database sends the I/O requests to I/O Server instances running on Hub Nodes over the Oracle Flex ASM network.
Source:
https://docs.oracle.com/database/122/CWAIX/understanding-oracle-flex-cluster-and-oracle-asm-flex-clusters.htm#CWAIX-GUID-26BBAAB0-765B-40D2-B59C-642AE69A64DF
Correct C,E,F