1 2 Previous Next 17 Replies Latest reply on Mar 8, 2013 6:01 AM by Billy~Verreynne Go to original post
      • 15. Re: Strange Delay in Database Connections
        Billy~Verreynne
        Sky13 wrote:

        I agree with the problem isolation as trouble shooting always comes down to that. I think I have done some of that at a high level by looking at the logs. It seems to be pointing at hand off from the Listener to the Database but just for the first one.
        To troubleshoot that, you need to enable debug tracing in the listener in order to see just what happens with the listener handoff to a dedicated server process.
        I was reading Doc ID 561429.1 and it seems to match and applies to my version of 11.2.0.1. We are planning to upgrade to 11.2.0.2 anyway so I will keep you all posted to what happens after the upgrade.
        As I read it, this is not a 11.2.0.1 bug - the same problem will still exist after a 11.2.0.2 upgrade. The note states that the problem is with the getaddrinfo() kernel (socket) call. That remains unchanged as the kernel and socket call interface do not change with an Oracle RDBMS upgrade.
        The getaddrinfo(3) function combines the functionality provided by the getipnodebyname(3), 
        getipnodebyaddr(3), getservbyname(3), and getservbyport(3) functions into a single interface.
        The thread-safe getaddrinfo(3) function creates one or more socket address structures that 
        can be used by the bind(2) and connect(2) system calls to create a client or a server socket.
        So this specific issue described in that note is a network related issue (the note refers to DNS misconfiguration). This means host and IP resolution is a problem. Nothing to do with RDBMS bugs in my view (having written network server code in the past).
        • 16. Re: Strange Delay in Database Connections
          Sky13
          I agree with you Billy that is does say it is a Network misconfiguration. I was hoping that Oracle put a workaround so they wound not be so dependent on that call... but we all know how well "Wishing Hard" works in software. We did do the update and still have the issue. Any idea on what might configured incorrectly in our DNS?
          • 17. Re: Strange Delay in Database Connections
            Billy~Verreynne
            The note you referred to, does however state a fix in 11.2.0.3 - so maybe Oracle has a workaround in place in that version? Or a better method doing whatever needs to be done.

            That note showed strace results where socket connect() calls are made to (DNS?) IP addresses on tcp port 53 (DNS service port). This is what seems to be the problem... However, the note does not give more technical details.

            And seeing that 11.2 is being widely used and this specific problem does not occur widely, it means something different in your setup and/or environment.

            It also could be that this note has nothing in common with the issue you have, beside sharing similar symptoms.

            I would still go for isolating the error using SQL*Plus as the client (with debug SQL*Net tracing enabled). Once the error can be reliably triggered in some way, then I would turn on server side SQL*Net/Listener debug tracing and resort to using commands like lsof and strace.

            Alternatively, file a SR with Oracle support and let them provide you with clear instructions of what to do in order to provide them with usable diagnostics to resolve the problem.
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