SQL Server 2008 R2 : Managing Workloads with the Resource Governor - Monitoring Resource Usage

• sys.dm_resource_governor_workload_groups— Returns workload group statistics along with the current in-memory configuration of the workload groups.

• sys.dm_resource_governor_resource_pools— Returns information about current state of your resource pools and resource pool statistics.

• sys.dm_resource_governor_configuration— Returns the in-memory configuration state of the Resource Governor. Output is the same as the sys.resource_governor_configuration system catalog view.

For example, the following query against the sys.dm_resource_governor_resource_pools DMV returns the configuration settings for each of the pools along with the actual memory allocated:

select name,
       min_cpu_percent as MinCPU,
       max_cpu_percent as MaxCPU,
       min_memory_percent as 'MinMEM%' ,
       max_memory_percent as 'MaxMEM%',
       max_memory_kb as 'MaxMemKB',
       used_memory_kb as 'UsedMemKB',
       target_memory_kb as 'TgtMemKB'
 from sys.dm_resource_governor_resource_pools
GO

name       MinCPU MaxCPU MinMEM% MaxMEM% MaxMemKB UsedMemKB TgtMemKB
---------- ------ ------ ------- ------- -------- --------- --------
internal   0      100    0       100     1556232  8296      1556232
default    0      100    0       100     389064   8336      389064
ReportPool 0      20     0       30      389064   280       389064
OLTPPool   80     100    75      100     1556232  40        1556232

The following example displays statistics on the requests received within the defined workgroups:

select
    cast(g.name as nvarchar(10)) as wg_name,
    cast(p.name as nvarchar(10)) as pool_name,
    total_request_count as totreqcnt,
    active_request_count as actreqcnt,
    g.total_cpu_usage_ms as tot_cpu_use,
    total_cpu_limit_violation_count as tot_clvc,
    g.request_max_cpu_time_sec as req_mcts,
    g.total_reduced_memgrant_count as tot_rmc
 from sys.dm_resource_governor_workload_groups g
    inner join
    sys.dm_resource_governor_resource_pools p
    on p.pool_id = g.pool_id
go
wg_name   pool_name  totreqcnt actreqcnt tot_cpu_use tot_clvc req_mcts tot_rmc
--------- ---------- --------- --------- ----------- -------- -------- -------
internal  internal   0         0         37314       0        0        0
default   default    784       2         97938       0        0        0
ReportWG1 ReportPool 170       1         476016      0        0        0
OLTPWG1   OLTPPool   161       0         1834        0        0        0


					  

Six other DMVs in SQL Server 2008 contain information related to Resource Governor:

• sys.dm_exec_query_memory_grants— Returns information about the queries that have acquired a memory grant or that still require a memory grant to execute. Resource Governor–related columns in this table are the group_id, pool_id, is_small, and ideal_memory_kb columns.

• sys.dm_exec_query_resource_semaphores— Returns information about the current query_resource semaphore status, providing general query-execution memory status information. The pool_id column provides a link to Resource Governor information.

• sys.dm_exec_session— Returns one row per session on SQL Server. The group_id column relates the information to Resource Governor workload groups.

• sys.dm_exec_requests— Returns information about each request currently executing within SQL Server. The group_id column relates the information to Resource Governor workload groups.

• sys.dm_exec_cached_plans— Returns a row for each query plan cached by SQL Server in the plan cache. The pool_id column relates the information to Resource Governor resource pools.

• sys.dm_os_memory_brokers— Returns information about internal allocations within SQL Server that use the Memory Manager. This information includes the following columns for the Resource Governor: pool_id, allocations_db_per_sec, predicted_allocations_kb, and overall_limit_kb.

The following query joins between sys.dm_exec_session and sys.dm_resource_governor_workload_groups to display which sessions are in which workload group:

SELECT
    CAST(g.name as nvarchar(10)) as poolname,
    s.session_id as 'session',
    s.login_time,
    CAST(s.host_name as nvarchar(15)) as host_name,
    CAST(s.program_name AS nvarchar(20)) as program_name
          FROM sys.dm_exec_sessions s
     INNER JOIN sys.dm_resource_governor_workload_groups g
          ON g.group_id = s.group_id
where g.name in ('default', 'ReportWG1', 'OLTPWG1')
go
poolname   session login_time              host_name       program_name
---------- ------- ----------------------- --------------- --------------------
default    51      2010-05-02 14:31:18.530 LATITUDED830-W7 Microsoft SQL Server
default    52      2010-05-02 14:31:21.990 LATITUDED830-W7 SQLAgent - Generic R
default    53      2010-05-02 14:31:23.533 LATITUDED830-W7 SQLAgent - TSQL JobS
default    55      2010-05-02 14:47:27.250 LATITUDED830-W7 Microsoft SQL Server
ReportWG1  60      2010-05-02 19:06:21.100 LATITUDED830-W7 Microsoft SQL Server
OLTPWG1    54      2010-05-02 21:03:03.020 LATITUDED830-W7 Microsoft SQL Server


					  

You can also monitor CPU and memory resources allocated by the Resource Governor through the Windows Performance Monitor via a couple of new performance counters:

• SQLServer: Resource Pool Stats

• SQLServer: Workload Stats

An instance of the SQLServer: Resource Pool Stats counter is available for each of the configured resource pools. Likewise, an instance of the SQLServer: Workload Stats counter is available for each of the configured workload groups (see Figure 1). These performance counters return the same information as that returned by the sys.dm_resource_governor_workload_groups and sys.dm_resource_governor_resource_pools DMVs but enable you to monitor these statistics over time.

Figure 1. Monitoring resource pool and workload group statistics in Performance Monitor.