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3 Replies Latest reply: Apr 10, 2013 6:32 AM by MohtashimShaikh RSS

Replication Groups not working as Desired.

MohtashimShaikh Newbie
Currently Being Moderated
I am trying to replicate this scenario.

http://docs.oracle.com/cd/E17904_01/web.1111/e13709/failover.htm#CHDEIFCF

I am tracking the Primary and Secondary server for a particular client request through the "Debug ON" option in apache "wlproxy.log".

I have seen that Rank 1 servers for a particular Primary server is not chosen as the secondary and lower ranks are treated as secondary which puzzles me.

For Servers A,B & C i have set the replication group as "Headquarters" and Prefered Secondary Group as "Crosstown" while for servers X,Y & Z i have set the replication group as "Crosstown" and Preferred Secondary Group as "Headquarters".

Is this a Bug in weblogic version 12. If not can you please explain me why ?
  • 1. Re: Replication Groups not working as Desired.
    RenévanWijk Oracle ACE
    Currently Being Moderated
    The explaination is beneath your link:

    "
    If a client connects to Server A and creates an HTTP session state,

    Servers Y and Z are most likely to host the replica of this state, since they reside on separate machines and are members of Server A's preferred secondary group.

    Server X holds the next-highest ranking because it is also a member of the preferred replication group (even though it resides on the same machine as the primary.)

    Server C holds the third-highest ranking since it resides on a separate machine but is not a member of the preferred secondary group.

    Server B holds the lowest ranking, because it resides on the same machine as Server A (and could potentially fail along with A if there is a hardware failure) and it is not a member of the preferred secondary group.
    "
  • 2. Re: Replication Groups not working as Desired.
    MohtashimShaikh Newbie
    Currently Being Moderated
    Exactly true Rene; but ...

    For "Y" as the primary, I was expecting Server A or Server B to be the secondary as they are listed in Server "Y"'s Preferred Secondary Replication Group i.e. "Headquarters" and they also reside on a different Machine.

    However, Here is my Apache debug entry shows that Server "C" somehow becomes the secondary for Primary Server "Y".

    Found Primary 10.101.221.47:9559 [*Y*] Found Secondary 10.101.221.47:9557:0 [*C*]

    Is this a bug or am I doing something wrong ?

    Below is for your reference where A,B,X are on one machine while C,Y,Z are on a different machine. The configuration is in-line with the Oracle document link shared.

    For "Y" as Primary Server; A & B should get Rank 1, Server C gets Rank 2, Server X gets Rank 3 and Server Z gets Rank 4.                              

    But this is not what I see in the Apache debug logs. Please clarify.

    Thank you for your attention.

    Edited by: Mohtashim Shaikh on Jan 14, 2013 2:29 AM

    Edited by: Mohtashim Shaikh on Jan 14, 2013 2:36 AM

    Edited by: Mohtashim Shaikh on Jan 14, 2013 2:39 AM

    Edited by: Mohtashim Shaikh on Jan 14, 2013 2:41 AM

    Edited by: Mohtashim Shaikh on Jan 14, 2013 3:29 AM

    Edited by: Mohtashim Shaikh on Jan 14, 2013 3:35 AM

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