Gbase 8s memory management

        GBASE 8S Shared memory is divided into types 3 class ： Resident memory segment （Resident Segment）、 Virtual memory segment （Virtual Segment） and Message segment （Message Segment）.

        1. Resident memory segment

         Here is a brief introduction to the parameter settings of several important parts of the resident memory

        PHYSBUFF 128, Unit is K, Physical log cache , The maximum value is ：（32767 * pagesize / 1024）,pagesize Is the system default pagesize, Linux by 2K. AIX by 4K. Generally set as 128—1024 that will do .

        LOGBUFF 64, Unit is K, Logical day break cache , The maximum value is ：（32767 * pagesize / 1024）,pagesize Is the system default pagesize, Linux by 2K. AIX by 4K. Generally set as 128 above , From the performance point of view, it is recommended to have a larger value . If... Is used Buffer Log mode for , From the security point of view of data loss ,LOGBUFF The value should be set as low as possible .

        BUFFERPOOL modify ：

        BUFFERPOOL   default,buffers=10000,lrus=8,lru_min_dirty=50,lru_max_dirty=60.5

        BUFFERPOOL   size=2K,buffers=5000,lrus=32,l ru_min_dirty=50,lru_max_dirty=60

        BUFFERPOOL   size=8K,buffers=5000,lrus=32,l ru_min_dirty=50,lru_max_dirty=60

         Only by modifying the inflation method can BUFFERPOOL value . In memory pagesize and dbspace Of pagesize Corresponding .

        2. Virtual memory segment

        RESIDENT 0： Whether the memory segment 、 Including resident memory , It allocates memory from the system to GBase 8S, If the memory is large , The starting process is long .

        SHMBASE 0x44000000L： Generally, it is the default value , Especially when multiple instances are installed on a single server .

        SHMVIRTSIZE 1024000： Virtual memory segment size , Considering the performance , General configuration 4GB above .

        SHMADD 1024000： The size of each automatic expansion of the virtual memory segment .

        SHMTOTAL 0：Gbase 8S Use total memory settings （ Including resident memory , Virtual memory segment , Message memory segment ）,0  It means unlimited size , Until the system is used up . Suggest ： In order to ensure system safety in the production system , Prevent memory overflow in the system , When the system memory is consumed , You can set a reasonable upper limit .

        3. Database message segment

         When applications and servers are deployed on the same physical server , use Shared memory channel The mechanism of ,GBase 8S A separate piece of memory will be used to communicate between the application and the server , It can improve the efficiency of communication .