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13.7.2.2 CREATE RESOURCE GROUP Syntax

CREATE RESOURCE GROUP group_name
    TYPE = {SYSTEM|USER}
    [VCPU [=] vcpu_spec [, vcpu_spec] ...]
    [THREAD_PRIORITY [=] N]
    [ENABLE|DISABLE]

vcpu_spec: {N | M - N}

CREATE RESOURCE GROUP is used for resource group management (see Section 8.12.5, “Resource Groups”). This statement creates a new resource group and assigns its initial attribute values. It requires the RESOURCE_GROUP_ADMIN privilege.

group_name identifies which resource group to create. If the group already exists, an error occurs.

The TYPE attribute is required. It should be SYSTEM for a system resource group, USER for a user resource group. The group type affects permitted THREAD_PRIORITY values, as described later.

The VCPU attribute indicates the CPU affinity; that is, the set of virtual CPUs the group can use:

  • If VCPU is not given, the resource group has no CPU affinity and can use all available CPUs.

  • If VCPU is given, the attribute value is a list of comma-separated CPU numbers or ranges:

    • Each number must be an integer in the range from 0 to the number of CPUs − 1. For example, on a system with 64 CPUs, the number can range from 0 to 63.

    • A range is given in the form MN, where M is less than or equal to N and both numbers are in the CPU range.

    • If a CPU number is an integer outside the permitted range or is not an integer, an error occurs.

Example VCPU specifiers (these are all equivalent):

VCPU = 0,1,2,3,9,10
VCPU = 0-3,9-10
VCPU = 9,10,0-3
VCPU = 0,10,1,9,3,2

The THREAD_PRIORITY attribute indicates the priority for threads assigned to the group:

  • If THREAD_PRIORITY is not given, the default priority is 0.

  • If THREAD_PRIORITY is given, the attribute value must be in the range from -20 (highest priority) to 19 (lowest priority). The priority for system resource groups must be in the range from -20 to 0. The priority for user resource groups must be in the range from 0 to 19. Use of different ranges for system and user groups ensures that user threads never have a higher priority than system threads.

ENABLE and DISABLE specify that the resource group is initially enabled or disabled. If neither is specified, the group is enabled by default. A disabled group cannot have threads assigned to it.

Examples:

  • Create an enabled user group that has a single CPU and the lowest priority:

    CREATE RESOURCE GROUP rg1
      TYPE = USER
      VCPU = 0
      THREAD_PRIORITY = 19;
  • Create a disabled system group that has no CPU affinity (can use all CPUs) and the highest priority:

    CREATE RESOURCE GROUP rg2
      TYPE = SYSTEM
      THREAD_PRIORITY = -20
      DISABLE;

Resource group management is local to the server on which it occurs. CREATE RESOURCE GROUP statements are not written to the binary log and are not replicated.