2 Replies Latest reply: Feb 24, 2014 4:06 AM by User477708-OC RSS

Scan log entry no local listener log entry

User477708-OC Journeyer
Currently Being Moderated    2 node rac.  OEL

RAC services.

My issue is with a service running on node 1.


have an application build in devart,  Pointed directly at 1 of my SCAN addresses so I know which node its coming to.  


connection comes in fine, but 2-3 times a day, for no reason we can find yet, the connection from client (several of them with same issue) times out.  restart app and works fine. 

Ive found that the SCAN address that its coming on has an entry in the SCAN listener log on the node where the service lives, but not the local listener.


For example,



08:25:01  > entry

08:27:03 > entry

08:28:38 > entry


but in the local listener log I only have

08:25:01  > entry

08:28:38 > entry



The 8:27:03 connection attempt coincides with the timeout on the app.


Firewall logs show same behaviour, for the good entries, connection coming and handing off and coming back out, for the bad connection, connection comes in but doesnt go back out.


Anyone got any experience of the SCAN listener not handing off a connection to local listener?

  • 1. Re: Scan log entry no local listener log entry
    Vandana B - Oracle Pro
    Currently Being Moderated



    The scan listener running on node2 will not always pass on the connection to node listener of node2, it may choose to pass on the connection to the node listener of node1 as well. You need to check if the connection was passed on to the node1 listener, did the failure happen after that.


    Also, ensure that the local_listener parameter and remote_listener parameter are set correctly in all the instances


    The local_listener should be pointing to the node vip and remote_listener should be pointing to scan


    Also, disable the firewall and check if you are still encountering the same issue



    Vandana - Oracle

  • 2. Re: Scan log entry no local listener log entry
    User477708-OC Journeyer
    Currently Being Moderated

    Yes, I had checked the local log on both nodes  While I agree that the scan listener wont always hand off to the local node, it should do if the RAC service being connected to is active on the same node.  I've packet traced connections before and seen this. 


    for example,

    SCAN is living on node 2, service on node 1,  in the packet trace from the client we see the SCAN being hit on node 2, connection is then refused on node 2 (as the service isnt there) and then we see the VIP on node 1 returning the connection as expected.  SCAN log on node 2 has entry, local listener log on node 1 has entry.  This is fine.


    Whats happening with my case is SCAN is living on node 1 and service is also on node 1.  The firewall allows all traffic in the range of the VIPs and the SCANs.  (same range)  x.x.129.0-30  

    SCANs are x.x.129.20 - 21 - 22

    VIPS are x.x.129.10 - 11


    The firewall log shows the 129.20 address (SCAN entry) coming in, but nothing going back out when this issue is hit.  The SCAN listener log for that address shows the connection but no local entry on either node, not that I was expecting to see it on node 2 but I did sanity check.


    Unable to turn off firewall but in any case this is not reproducible at will so would have to leave it off indefinitely to show the issue wasnt happening at all for the period the firewall was off.  

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