3 Replies Latest reply on Apr 8, 2019 2:55 AM by Geoff Grandstaff-Oracle

    Reverse Offload to DB servers

    Arturo Gutierrez

      Hi,

      Is possible to know the number of times a reverse offload to database servers happen?

      Any statistic at cell or database node available?

       

      Thanks

      Arturo

        • 1. Re: Reverse Offload to DB servers
          Geoff Grandstaff-Oracle

          Hi, Arturo.

           

          cellsrvstat (on each individual cell) has a section for 'Reverse Offload related stats'. Ex:

           

          == Reverse Offload related stats ==
          Number of Remote Nodes                            (I)          0              7
          Number of Remote Instances                        (I)          0              8
          Current Cell CPU utilization                      (I)          0              1
          Number of requests                                (C)          0      31330706
          Number of requests that were pushed              (C)          0        2085719
          Average pushback rate for since last stat update  (I)          0              0
          Average pushback rate for last 200 ms            (I)          0              0
          Num of reqs not pushed due to low cell cpu        (C)          0      19360302
          Num of reqs not pushed due to high cell outnet    (C)          0              0
          Num of reqs not pushed due to high db node innet  (C)          0              0
          Num rate increase by reverse offload info from db (C)          0          36398
          Num rate decrease by reverse offload info from db (C)          0        316093
          Num rate increases from db node cpu information  (C)          0          58745
          Num rate decreases from db node cpu information  (C)          0          7437
          Num rate decreases from low cell cpu utilization  (C)          0      552905618
          Num rate decreases from high cell outnet util    (C)          0              0
          Num rate decreases from high db node innet util  (C)          0              0
          

           

           

          Also, while not a "count", there is also the statistic 'cell physical IO bytes sent directly to DB node to balance CPU'.

           

          https://docs.oracle.com/en/engineered-systems/exadata-database-machine/sagug/exadata-storage-server-monitoring.html#GUID…

           

          Hope this helps.

           

          Regards,

           

          Geoff

          • 2. Re: Reverse Offload to DB servers
            Arturo Gutierrez

            Hi Geoff,

            Thanks for the reply.

             

            I've generated the report with Exawatcher.

            I think that this stats are the main:

            Num of reqs not pushed due to low cell cpu        (C)           0              0

            Num of reqs not pushed due to high cell outnet    (C)           0              0

            Num of reqs not pushed due to high db node innet  (C)           0              0

             

            Means, that no reverse offloading is ocurring.

             

            Thanks

            Arturo

            • 3. Re: Reverse Offload to DB servers
              Geoff Grandstaff-Oracle

              Hi, Arturo.

               

              As you probably noticed from the output I posted from cellsrvstat and what you posted with Exawatcher, cellssrvstat is one of the collectors for Exawatcher.

               

              https://docs.oracle.com/en/engineered-systems/exadata-database-machine/sagug/exadata-storage-server-maintaining.html#GUI…

               

              Have a great day.

               

              Regards,

               

              Geoff