2 Replies Latest reply on Nov 27, 2018 2:40 PM by 3313231

    Capacity planning for the database


      Hi All,


      Can anyone please guide me how to estimate my server memory requirements and database parameters in terms of increase in number of users and data growth. What are the factors that are needed to be considered?

      I have a production RAC server where my swap memory is almost utilised and in peak load one of the nodes gets evicted due to high swapping from OS end.


      Thanks and Regards


        • 1. Re: Capacity planning for the database
          Pravin Takpire

          Can you post Server configurations and some estimated user load




          • 2. Re: Capacity planning for the database

            Hi Pravin,


            The server is hosted in DBaaS. The memory is of 30Gb each on both the nodes with swap space of 4Gb in both the nodes.



            free -th

                         total       used       free     shared    buffers     cached

            Mem:           29G        28G       998M        10G        46M        11G

            -/+ buffers/cache:        16G        12G

            Swap:         4.0G       3.5G       559M

            Total:         33G        31G       1.5G


            top - 14:35:04 up 95 days,  1:12,  2 users,  load average: 3.16, 3.41, 3.26

            Tasks: 1055 total,   2 running, 1053 sleeping,   0 stopped,   0 zombie

            Cpu(s):  9.8%us,  4.2%sy,  0.0%ni, 85.1%id,  0.3%wa,  0.0%hi,  0.2%si,  0.4%st

            Mem:  30616760k total, 29285080k used,  1331680k free,    47884k buffers

            Swap:  4194300k total,  3629392k used,   564908k free, 11724068k cached


            SQL> select name, value/1024/1024/1024 from v$pgastat;



            NAME                                                             VALUE/1024/1024/1024

            ---------------------------------------------------------------- --------------------

            aggregate PGA target parameter                                                    7.5

            aggregate PGA auto target                                                  4.22212315

            global memory bound                                                        .749998093

            total PGA inuse                                                            3.51766682

            total PGA allocated                                                         4.4830389

            maximum PGA allocated                                                      5.42578411

            total freeable PGA memory                                                  .384887695

            process count                                                              6.7521E-07

            max processes count                                                        7.6648E-07

            PGA memory freed back to OS                                                216.756531

            total PGA used for auto workareas                                          .708415985

            maximum PGA used for auto workareas                                        1.90459156

            total PGA used for manual workareas                                                 0

            maximum PGA used for manual workareas                                       .01036644

            over allocation count                                                               0

            bytes processed                                                             333.71707

            extra bytes read/written                                                   5.05296516

            cache hit percentage                                                       9.1735E-08

            recompute count (total)                                                    .000028026



            19 rows selected.




            Load Average sometime hits as above 300 when heavy swapping occurs, at the time of node eviction.


            Thanks and Regards