おそらく、SQL Serverを使用するすべての人が、そのような状況に自分自身を見つけたか、それでもそうなるでしょう。金曜日の夜、あなたはすでに精神的に休む準備ができており、SQL ServerのCPUに高い負荷がかかっているという通知が届き始め、電話が鳴り始め、監視システムに表示されます。 KDPVのような写真。
そして、一方で、これは特に問題ではないかもしれません-はい、それはサーバーにとって難しいです、はい、それは不快です、しかし結局のところ、主よ、あなたのレポートは15秒ではなく45秒で形成されます-ビジネス、あなたが見る-多くの方がいらっしゃいますが、サーバーは1つなので、少し待つ必要があります。しかし、これだけで、待つことができないビジネスプロセスがあるとしたらどうでしょうか。このような負荷の下で、製品の販売が非常に遅くなり、購入者が購入を拒否した場合はどうなりますか?
プロセス/ユーザーを分離してSQLServerに伝えることができれば素晴らしいと思います-これらは非常に重要な人物であり、クエリを最初に実行する必要があります。しかし、これらはもちろん重要ですが、もう少し待つことができます。しかし、これは一般的に、書き直しに長い間必要とされてきた監視システムからの要求であり、ここで重要なことをしている間は、それらをまったく無視することができます。
また、リソースガバナーの助けを借りて、実際にそれらを分離できる場合もあります。
一度にいくつかのメモ:
Resource Governorは、EnterpriseEditionでのみ使用できます。他のエディションがある場合(まあ、Developerもありますが、本番環境ではありませんよね?)-残念ながら、それを使用することはできません。
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CREATE RESOURCE POOL (MSDN):
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]
:
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, CREATE WORKLOAD GROUP (MSDN):
CREATE WORKLOAD GROUP group_name
[ WITH
( [ IMPORTANCE = { LOW | MEDIUM | HIGH } ]
[ [ , ] REQUEST_MAX_MEMORY_GRANT_PERCENT = value ]
[ [ , ] REQUEST_MAX_CPU_TIME_SEC = value ]
[ [ , ] REQUEST_MEMORY_GRANT_TIMEOUT_SEC = value ]
[ [ , ] MAX_DOP = value ]
[ [ , ] GROUP_MAX_REQUESTS = value ] )
]
[ USING {
[ pool_name | "default" ]
[ [ , ] EXTERNAL external_pool_name | "default" ] ]
} ]
[ ; ]
:
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Resource Governor :
ALTER RESOURCE GOVERNOR DISABLE;
// / .
CPU :
CREATE RESOURCE POOL [pool1]
WITH (
MIN_CPU_PERCENT = 15,
MAX_CPU_PERCENT = 15,
CAP_CPU_PERCENT = 20
);
CREATE RESOURCE POOL [pool2]
WITH (
MIN_CPU_PERCENT = 50,
MAX_CPU_PERCENT = 90
);
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:
CREATE WORKLOAD GROUP [pool1_group1]
WITH (
IMPORTANCE = HIGH,
REQUEST_MAX_CPU_TIME_SEC = 5,
MAX_DOP = 2
)
USING [pool1];
CREATE WORKLOAD GROUP [pool2_group1]
WITH (
IMPORTANCE = HIGH
)
USING [pool2];
CREATE WORKLOAD GROUP [pool2_group2]
WITH (
IMPORTANCE = MEDIUM
)
USING [pool2];
CREATE WORKLOAD GROUP [pool2_group3]
WITH (
IMPORTANCE = LOW,
GROUP_MAX_REQUESTS = 1
)
USING [pool2];
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, . , .
USE [StackOverflow2013]
GO
CREATE LOGIN p1g1 WITH PASSWORD = N'1', CHECK_POLICY = OFF, CHECK_EXPIRATION = OFF;
CREATE LOGIN p2g1 WITH PASSWORD = N'1', CHECK_POLICY = OFF, CHECK_EXPIRATION = OFF;
CREATE LOGIN p2g2 WITH PASSWORD = N'1', CHECK_POLICY = OFF, CHECK_EXPIRATION = OFF;
CREATE LOGIN p2g3 WITH PASSWORD = N'1', CHECK_POLICY = OFF, CHECK_EXPIRATION = OFF;
CREATE USER p1g1 FOR LOGIN p1g1;
CREATE USER p2g1 FOR LOGIN p2g1;
CREATE USER p2g2 FOR LOGIN p2g2;
CREATE USER p2g3 FOR LOGIN p2g3;
EXEC sp_addrolemember N'db_owner', N'p1g1';
EXEC sp_addrolemember N'db_owner', N'p2g1';
EXEC sp_addrolemember N'db_owner', N'p2g2';
EXEC sp_addrolemember N'db_owner', N'p2g3';
:
USE [master]
GO
CREATE FUNCTION fnClassify()
RETURNS SYSNAME
WITH SCHEMABINDING
AS
BEGIN
RETURN
CASE ORIGINAL_LOGIN()
WHEN 'p1g1' THEN 'pool1_group1'
WHEN 'p2g1' THEN 'pool2_group1'
WHEN 'p2g2' THEN 'pool2_group2'
WHEN 'p2g3' THEN 'pool2_group3'
ELSE 'default' END;
END;
, :
SELECT master.dbo.fnClassify();
- default,
NULL - - Resource Governor , default.
, - Resource Governor :
ALTER RESOURCE GOVERNOR WITH (CLASSIFIER_FUNCTION = dbo.fnClassify);
ALTER RESOURCE GOVERNOR RECONFIGURE;
, .
SELECT
s.session_id,
s.login_name,
wg.group_id,
wg.name AS workload_group_name,
wg.pool_id,
rp.name AS pool_name
FROM sys.dm_exec_sessions s
JOIN sys.dm_resource_governor_workload_groups wg ON s.group_id = wg.group_id
JOIN sys.dm_resource_governor_resource_pools rp ON wg.pool_id = rp.pool_id
WHERE s.session_id >= 50
, "" . Object Explorer default.
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p1g1 , , , , 8 i5-8250u,
USE StackOverflow2013;
GO
SELECT SUM (CAST (VoteTypeId AS decimal(12,2))) / AVG (CAST (VoteTypeId AS decimal(14,4)))
FROM dbo.Votes
OPTION (MAXDOP 8);
GO
, perfmon SQLServer: Workload Group Stats: CPU Usage% CPU Delayed % pool1_group1:
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p2g1 (IMPORTANCE = HIGH) p2g3 (IMPORTANCE = LOW):
USE StackOverflow2013;
GO
SELECT SUM (CAST (VoteTypeId AS decimal(12,2))) / AVG (CAST (VoteTypeId AS decimal(14,4))) * AVG (CAST (PostId AS decimal(19,4)))
FROM dbo.Votes
OPTION (MAXDOP 8);
GO
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SELECT
s.session_id,
s.status,
r.task_address,
r.scheduler_id
FROM sys.dm_exec_sessions s
LEFT JOIN sys.dm_exec_requests r ON s.session_id = r.session_id
WHERE s.login_name = N'p2g3';
running, (request) (). , , ().
IO. Resource Governor, :
USE [master];
GO
ALTER RESOURCE GOVERNOR WITH (CLASSIFIER_FUNCTION = NULL);
ALTER RESOURCE GOVERNOR DISABLE;
DROP WORKLOAD GROUP [pool1_group1];
DROP WORKLOAD GROUP [pool2_group1];
DROP WORKLOAD GROUP [pool2_group2];
DROP WORKLOAD GROUP [pool2_group3];
DROP RESOURCE POOL [pool1];
DROP RESOURCE POOL [pool2];
IO . , - , . IOPS , , Resource Governor .
- : /, -, , ( ):
USE [StackOverflow2013]
GO
DBCC DROPCLEANBUFFERS;
GO
SELECT *
FROM dbo.Posts; -- 1
SELECT *
FROM dbo.Comments; -- 2
SELECT *
FROM dbo.Votes; -- 3
, Enterprise (, , Developer) Edition "shared scan" . .
, SQL Server 75 IOPS ( , , ). , , , Resource Governor.
USE [master];
GO
CREATE RESOURCE POOL [pool1]
WITH (
MIN_IOPS_PER_VOLUME = 50
);
CREATE RESOURCE POOL [pool2]
WITH (
MIN_IOPS_PER_VOLUME = 30,
MAX_IOPS_PER_VOLUME = 50
);
GO
CREATE WORKLOAD GROUP [pool1_group1]
USING [pool1];
CREATE WORKLOAD GROUP [pool2_group1]
USING [pool2];
ALTER FUNCTION fnClassify()
RETURNS SYSNAME
WITH SCHEMABINDING
AS
BEGIN
RETURN
CASE ORIGINAL_LOGIN()
WHEN 'p1g1' THEN 'pool1_group1'
WHEN 'p2g1' THEN 'pool2_group1'
ELSE 'default' END;
END;
GO
ALTER RESOURCE GOVERNOR WITH (CLASSIFIER_FUNCTION = dbo.fnClassify);
ALTER RESOURCE GOVERNOR RECONFIGURE;
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, , , , , . , . , , , , - , , , .
IOの場合はおそらく役立つでしょうが、パーセンテージではなく、操作の数で直接操作し、読み取りと書き込みに分割せずに操作するため、すべてを非常に慎重に計算する必要があります。さらに、すべてのボリュームに一度に適用される同じ操作数を指定し、「帯域幅」が異なるアレイ/ディスクを接続すると、このようなIO制限の使用が大幅に削減されます。
DACを忘れないように注意してください。
追加の読み物: