CREATE RESOURCE POOL (Transact-SQL)

Articol
12/29/2022

Applies to: SQL Server Azure SQL Managed Instance

Creates a Resource Governor resource pool in SQL Server. A resource pool represents a subset of the physical resources (memory, CPUs and IO) of an instance of the Database Engine. Resource Governor enables a database administrator to distribute server resources among resource pools, up to a maximum of 64 pools. Resource Governor is not available in every edition of SQL Server. For a list of features that are supported by the editions of SQL Server, see Features Supported by the Editions of SQL Server 2016.

Transact-SQL syntax conventions

Syntax

CREATE RESOURCE POOL pool_name  
[ WITH  
    (  
        [ MIN_CPU_PERCENT = value ]  
        [ [ , ] MAX_CPU_PERCENT = value ]   
        [ [ , ] CAP_CPU_PERCENT = value ]   
        [ [ , ] AFFINITY {SCHEDULER =  
                  AUTO 
                | ( <scheduler_range_spec> )   
                | NUMANODE = ( <NUMA_node_range_spec> )
                } ]   
        [ [ , ] MIN_MEMORY_PERCENT = value ]  
        [ [ , ] MAX_MEMORY_PERCENT = value ]  
        [ [ , ] MIN_IOPS_PER_VOLUME = value ]  
        [ [ , ] MAX_IOPS_PER_VOLUME = value ]  
    )   
]  
[;]  
  
<scheduler_range_spec> ::=  
{ SCHED_ID | SCHED_ID TO SCHED_ID }[,...n]  
  
<NUMA_node_range_spec> ::=  
{ NUMA_node_ID | NUMA_node_ID TO NUMA_node_ID }[,...n]

Arguments

pool_name
Is the user-defined name for the resource pool. pool_name is alphanumeric, can be up to 128 characters, must be unique within an instance of SQL Server, and must comply with the rules for identifiers.

MIN_CPU_PERCENT =value
Specifies the guaranteed average CPU bandwidth for all requests in the resource pool when there is CPU contention. value is an integer with a default setting of 0. The allowed range for value is from 0 through 100.

MAX_CPU_PERCENT =value
Specifies the maximum average CPU bandwidth that all requests in resource pool will receive when there is CPU contention. value is an integer with a default setting of 100. The allowed range for value is from 1 through 100.

CAP_CPU_PERCENT =value
Applies to: SQL Server 2012 (11.x) and later.

Specifies a hard cap on the CPU bandwidth that all requests in the resource pool will receive. Limits the maximum CPU bandwidth level to be the same as the specified value. value is an integer with a default setting of 100. The allowed range for value is from 1 through 100.

AFFINITY {SCHEDULER = AUTO | ( <scheduler_range_spec> ) | NUMANODE = (<NUMA_node_range_spec>)}
Applies to: SQL Server 2012 (11.x) and later.

Attach the resource pool to specific schedulers. The default value is AUTO.

AFFINITY SCHEDULER = ( <scheduler_range_spec> ) maps the resource pool to the SQL Server schedules identified by the given IDs. These IDs map to the values in the scheduler_id column in sys.dm_os_schedulers (Transact-SQL).

When you use AFFINITY NUMANODE = ( <NUMA_node_range_spec> ), the resource pool is affinitized to the SQL Server schedulers that map to the physical CPUs that correspond to the given NUMA node or range of nodes. You can use the following Transact-SQL query to discover the mapping between the physical NUMA configuration and the SQL Server scheduler IDs.

SELECT osn.memory_node_id AS [numa_node_id], sc.cpu_id, sc.scheduler_id  
FROM sys.dm_os_nodes AS osn  
INNER JOIN sys.dm_os_schedulers AS sc   
    ON osn.node_id = sc.parent_node_id   
    AND sc.scheduler_id < 1048576;

MIN_MEMORY_PERCENT =value
Specifies the minimum amount of memory reserved for this resource pool that can not be shared with other resource pools. value is an integer with a default setting of 0 The allowed range for value is from 0 to 100.

MAX_MEMORY_PERCENT =value
Specifies the total server memory that can be used by requests in this resource pool. value is an integer with a default setting of 100. The allowed range for value is from 1 through 100.

MIN_IOPS_PER_VOLUME =value
Applies to: SQL Server 2014 (12.x) and later.

Specifies the minimum I/O operations per second (IOPS) per disk volume to reserve for the resource pool. The allowed range for value is from 0 through 2^31-1 (2,147,483,647). Specify 0 to indicate no minimum threshold for the pool. The default is 0.

MAX_IOPS_PER_VOLUME =value
Applies to: SQL Server 2014 (12.x) and later.

Specifies the maximum I/O operations per second (IOPS) per disk volume to allow for the resource pool. The allowed range for value is from 0 through 2^31-1 (2,147,483,647). Specify 0 to set an unlimited threshold for the pool. The default is 0.

If the MAX_IOPS_PER_VOLUME for a pool is set to 0, the pool is not governed at all and can take all the IOPS in the system even if other pools have MIN_IOPS_PER_VOLUME set. For this case, we recommend that you set the MAX_IOPS_PER_VOLUME value for this pool to a high number (for example, the maximum value 2^31-1) if you want this pool to be governed for IO.

Remarks

MIN_IOPS_PER_VOLUME and MAX_IOPS_PER_VOLUME specify the minimum and maximum reads or writes per second. These reads or writes can be of any size and do not indicate minimum or maximum throughput.

The values for MAX_CPU_PERCENT and MAX_MEMORY_PERCENT must be greater than or equal to the values for MIN_CPU_PERCENT and MIN_MEMORY_PERCENT, respectively.

CAP_CPU_PERCENT differs from MAX_CPU_PERCENT in that workloads associated with the pool can use CPU capacity above the value of MAX_CPU_PERCENT if it is available, but not above the value of CAP_CPU_PERCENT.

The total CPU percentage for each affinitized component (scheduler(s) or NUMA node(s)) should not exceed 100 percent.

Permissions

Requires CONTROL SERVER permission.

Examples

1. Shows how to create a resource pool

This example created a resource pool named "bigPool". This pool uses the default Resource Governor settings.

CREATE RESOURCE POOL bigPool;  
GO  
ALTER RESOURCE GOVERNOR RECONFIGURE;  
GO

2. Set the CAP_CPU_PERCENT to a hard cap and set AFFINITY SCHEDULER

Set the CAP_CPU_PERCENT to a hard cap of 30 percent and sets AFFINITY SCHEDULER to a range of 0 to 63, 128 to 191.

Applies to: SQL Server 2012 (11.x) and later.

CREATE RESOURCE POOL PoolAdmin  
WITH (  
     MIN_CPU_PERCENT = 10,  
     MAX_CPU_PERCENT = 20,  
     CAP_CPU_PERCENT = 30,  
     AFFINITY SCHEDULER = (0 TO 63, 128 TO 191),  
     MIN_MEMORY_PERCENT = 5,  
     MAX_MEMORY_PERCENT = 15  
      );

3. Set MIN_IOPS_PER_VOLUME and MAX_IOPS_PER_VOLUME

Set MIN_IOPS_PER_VOLUME to 20 and MAX_IOPS_PER_VOLUME to 100. These values govern the physical I/O read and write operations that are available for the resource pool.

Applies to: SQL Server 2014 (12.x) and later.

CREATE RESOURCE POOL PoolAdmin  
WITH (  
    MIN_IOPS_PER_VOLUME = 20,  
    MAX_IOPS_PER_VOLUME = 100  
      );

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