3 Replies Latest reply on Apr 9, 2013 2:28 PM by saratpvv

    LGWR SYNC & NET_TIMEOUT

    1001883
      Hii,

      Our parameter is set to LGWR SYNC. Let us say, the network connection between primary and standby is disconnected even before RFS sends back an acknowledgment to the LNS process.

      1) The LNS process will remain in a wait state till the NET_TIMEOUT. Right?

      2) If the network between primary & standby is not re-established within NET_TIMEOUT, will the primary database be shutdown after NET_TIMEOUT period?

      Any help will be highly appreciated.

      Thanks
        • 1. Re: LGWR SYNC & NET_TIMEOUT
          Sunny kichloo
          1) The LNS process will remain in a wait state till the NET_TIMEOUT. Right?
          You can say LNS process is in wait state to the value set in NET_TIMEOUT.
          2) If the network between primary & standby is not re-established within NET_TIMEOUT, will the primary database be shutdown after NET_TIMEOUT period?
          Redo Transport Session to the Standby database is terminated.


          Source:

          http://docs.oracle.com/cd/E14072_01/server.112/e10700/log_arch_dest_param.htm#i83182

          Edited by: Sunny kichloo on Apr 9, 2013 12:06 AM
          • 2. Re: LGWR SYNC & NET_TIMEOUT
            1001883
            Hii Sunny kichloo

            Thanks for your valuable response and link. I have gone through the link you provided.

            As per oracle doc "If an acknowledgement is not received within NET_TIMEOUT seconds, an error is logged and the redo transport session to that destination is terminated."

            In response to 2nd answer. I have couple of questions

            If an acknowledgement from RFS is not back to LNS due to network down, LGWR cannot send a commit acknowledgment to the user and the commit operation of the primary database is held up.

            1) If the DB is in Max Performance mode will it freeze until the network problem is solved?

            2) If the DB is in Max Protection mode will it freeze or will it shutdown?

            Thanks
            • 3. Re: LGWR SYNC & NET_TIMEOUT
              saratpvv
              If the DB is in Max Protection mode will it freeze or will it shutdown? 
              If you have set Maximum Protection, you have chosen a configuration that guarantees that no data loss will occur. You have set this up by specifying the LWGR, SYNC, and AFFIRM attributes of the LOG_ARCHIVE_DEST_n parameter for at least one standby database. This mode provides the highest level of data protection possible and to achieve this the redo data needed to reocver each transaction must be written to both the local online redo log and the standby redo log on at least one standby database before the transaction commits. To ensure data loss cannot occur, the primary database shuts down if a fault (such as the network going down) prevents it from writing its redo stream to at least one remote standby redo log.