{"id":2500,"date":"2017-03-10T16:11:46","date_gmt":"2017-03-10T19:11:46","guid":{"rendered":"http:\/\/www.dbarj.com.br\/?p=2500\/"},"modified":"2017-03-10T16:34:04","modified_gmt":"2017-03-10T19:34:04","slug":"check-hub-node-leaf-node-connected-oracle-flex-cluster","status":"publish","type":"post","link":"https:\/\/www.dbarj.com.br\/en\/2017\/03\/check-hub-node-leaf-node-connected-oracle-flex-cluster\/","title":{"rendered":"Check which Hub Node is Leaf Node connected to in Oracle Flex Cluster"},"content":{"rendered":"

In this article, I will show how to detect to which Hub Node is your Leaf Node connected to in an Oracle Flex Cluster scenario where you have multiple Hub Servers.<\/p>\n

First of all, let’s check our current scenario:<\/p>\n

[oracle@oranode3 ~]$ crsctl get node role status -all\r\nNode 'oranode1' active role is 'hub'\r\nNode 'oranode2' active role is 'hub'\r\nNode 'oranode3' active role is 'leaf'<\/pre>\n
So in my current configuration I have 2 Hub Nodes (oranode1<\/strong> and oranode2<\/strong>) but only 1 Leaf Node (oranode3<\/strong>).<\/p>\n
To check to which of those 2 Hub Nodes is my Leaf Node connected, I need to check on ocssdrim.trc file to which node is my leaf periodically pinging and checking availability:<\/p>\n
[oracle@oranode3 ~]$ export GRID_BASE=\/u01\/app\/grid\r\n[oracle@oranode3 ~]$ cat  $GRID_BASE\/diag\/crs\/$(hostname -s)\/crs\/trace\/ocssdrim.trc | grep 'Sending a ping msg to' | tail -1\r\n2017-03-10 13:57:32.916716 :    CSSD:3347568384: clssbnmc_PeriodicPing_CB: Sending a ping msg to host oranode1, number 1, using handle (0x2525390) last msg to hub at 70720064, connection timeout at 70750064, current time 70722514\r\n<\/pre>\n
So by the message above, the\u00a0oranode3<\/strong> is periodically sending pings to oranode1<\/strong>, meaning this is the node to which it is connected.<\/p>\n
What happens when a Hub Node ceases to be a part of the cluster? In such scenario, the Leaf Nodes associated with that Hub Node will failover to one of the surviving nodes in the cluster.<\/p>\n
Let’s try that. On oranode1<\/strong>:<\/p>\n
[root@oranode1 ~]# crsctl stop crs\r\nCRS-2791: Starting shutdown of Oracle High Availability Services-managed resources on 'oranode1'\r\nCRS-2673: Attempting to stop 'ora.crsd' on 'oranode1'\r\nCRS-2790: Starting shutdown of Cluster Ready Services-managed resources on 'oranode1'\r\n(...)\r\nCRS-2793: Shutdown of Oracle High Availability Services-managed resources on 'oranode1' has completed\r\nCRS-4133: Oracle High Availability Services has been stopped.<\/pre>\n
Now\u00a0back on oranode3<\/strong> let’s check for any destroyed connection:<\/p>\n
[oracle@oranode3 ~]$ cat  $GRID_BASE\/diag\/crs\/$(hostname -s)\/crs\/trace\/ocssdrim.trc | grep 'Destroying connection' | tail -1\r\n2017-03-10 14:02:02.932005 :    CSSD:3347568384: clssbnmConnDestroy: Destroying connection object (0x7f1ab4034310) for host oranode1<\/pre>\n
And the new connection is\u00a0estabelished to:<\/p>\n
[oracle@oranode3 ~]$ cat  $GRID_BASE\/diag\/crs\/$(hostname -s)\/crs\/trace\/ocssdrim.trc | grep 'Sending a ping msg to' | tail -1\r\n2017-03-10 14:04:34.377566 :    CSSD:3347568384: clssbnmc_PeriodicPing_CB: Sending a ping msg to host oranode2, number 2, using handle (0x1f83750) last msg to hub at 71141124, connection timeout at 71171124, current time 71143974<\/pre>\n
As expected, oranode2<\/strong>, the only survived Hub Node.<\/p>\n
References:<\/p>\n