CREATE EXTERNAL RESOURCE POOL (Transact-SQL)

THIS TOPIC APPLIES TO: yesSQL Server (starting with 2016)noAzure SQL DatabasenoAzure SQL Data Warehouse noParallel Data Warehouse

Applies to: SQL Server 2016 R Services (In-Database) and SQL Server 2017 Machine Learning Services (In-Database)

Creates an external pool used to define resources for external processes. A resource pool represents a subset of the physical resources (memory and CPUs) 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.

  • For R Services (In-Database) in SQL Server 2016, the external pool governs rterm.exe, BxlServer.exe, and other processes spawned by them.

  • For Machine Learning Services (In-Database) in SQL Server 2017, the external pool governs the R processes listed for SQL Server 2016, as well as python.exe, BxlServer.exe, and other processes spawned by them.

Topic link icon Transact-SQL Syntax Conventions.

Syntax

CREATE EXTERNAL RESOURCE POOL pool_name  
[ WITH (  
    [ MAX_CPU_PERCENT = value ]  
    [ [ , ] AFFINITY CPU =    
            {  
                AUTO   
              | ( <cpu_range_spec> )   
              | NUMANODE = ( <NUMA_node_id> )   
            } ]   
    [ [ , ] MAX_MEMORY_PERCENT = value ]  
    [ [ , ] MAX_PROCESSES = value ]   
    )   
]  
[ ; ]  

<CPU_range_spec> ::=    
{ CPU_ID | CPU_ID  TO CPU_ID } [ ,...n ]  

Arguments

pool_name
Is the user-defined name for the external 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.

MAX_CPU_PERCENT =value
Specifies the maximum average CPU bandwidth that all requests in the external resource pool can 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.

AFFINITY {CPU = AUTO | ( <CPU_range_spec> ) | NUMANODE = (<NUMA_node_range_spec>)} Attach the external resource pool to specific CPUs. The default value is AUTO.

AFFINITY CPU = ( <CPU_range_spec> ) maps the external resource pool to the SQL Server CPUs identified by the given CPU_IDs.

When you use AFFINITY NUMANODE = ( <NUMA_node_range_spec> ), the external resource pool is affinitized to the SQL Server physical CPUs that correspond to the given NUMA node or range of nodes.

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

MAX_PROCESSES =value
Specifies the maximum number of processes allowed for the external resource pool. Specify 0 to set an unlimited threshold for the pool, which is thereafter bound only by computer resources. The default is 0.

Remarks

The Database Engine implements the resource pool when you execute the ALTER RESOURCE GOVERNOR RECONFIGURE statement.

For general information about resource pools, see Resource Governor Resource Pool, sys.resource_governor_external_resource_pools (Transact-SQL), and sys.dm_resource_governor_external_resource_pool_affinity (Transact-SQL).

For information specific to managing external resource pools used for machine learning, see Resource governance for machine learning in SQL Server.

Permissions

Requires CONTROL SERVER permission.

Examples

The following statement defines an external pool that restricts CPU usage to 75 percent and the maximum memory to 30 percent of the available memory on the computer.

CREATE EXTERNAL RESOURCE POOL ep_1
WITH (  
    MAX_CPU_PERCENT = 75
    , AFFINITY CPU = AUTO
    , MAX_MEMORY_PERCENT = 30
);
GO
ALTER RESOURCE GOVERNOR RECONFIGURE;
GO

See also

external scripts enabled Server Configuration Option
sp_execute_external_script (Transact-SQL)
ALTER EXTERNAL RESOURCE POOL (Transact-SQL)
DROP EXTERNAL RESOURCE POOL (Transact-SQL)
CREATE RESOURCE POOL (Transact-SQL)
CREATE WORKLOAD GROUP (Transact-SQL)
Resource Governor Resource Pool
sys.resource_governor_external_resource_pools (Transact-SQL)
sys.dm_resource_governor_external_resource_pool_affinity (Transact-SQL)
ALTER RESOURCE GOVERNOR (Transact-SQL)