连接超时
对于连接超时，首先可以查看Connectivity Ring Buffer中的LoginTimers类型错误来分析，如果想获得更详尽的信息，再通过抓包工具network monitor。
具体方法和语句可参考以下文章：
https://blogs.msdn.microsoft.com/apgcdsd/2011/11/20/ring-buffersql-server-2008/
http://ultrasql.blog.51cto.com/9591438/1583446
查询超时
对于查询超时，针对SQL Server 2012以下的版本，使用Profiler的TSQL_Duration模板的基础上，添加“Errors and Warnings”下的“Attention”，根据捕获到的Attention结合上下文去查找相应的语句；对于SQL Server 2012及以上版本，直接使用扩展事件监控sqlserver.attention事件，直接输出sql_text。
以下为XE脚本：
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
|
use tempdb
go
if exists (
select
*
from
sys.objects
where
name
=
'sqlws_xev_attention'
)
drop
view
sqlws_xev_attention
go
create
view
sqlws_xev_attention
as
with
xevents (event_data)
as
(
select
event.query(
'.'
)
as
event_data
from
((
select
cast
(xest.target_data
as
xml)
as
target_data
from
sys.dm_xe_sessions
as
xes
inner
join
sys.dm_xe_session_targets
as
xest
on
(xes.address = xest.event_session_address)
where
xes.
name
=
'sqlws_xevents_attention'
and
xest.target_name =
'ring_buffer'
)
as
td
cross
apply target_data.nodes (
'//event[@name="attention"]'
)
as
x (event))
)
select
event_data.value (
'(event/@name)[1]'
,
'varchar(max)'
)
as
event_name,
event_data.value (
'(event/@timestamp)[1]'
,
'datetime'
)
as
event_timestamp,
event_data.value (
'(event/data[@name="duration"]/value)[1]'
,
'bigint'
)
as
[duration],
event_data.value (
'(event/data[@name="request_id"]/value)[1]'
,
'int'
)
as
[request_id],
event_data.value (
'(event/action[@name="client_app_name"]/value)[1]'
,
'nvarchar(max)'
)
as
action_client_app_name,
event_data.value (
'(event/action[@name="client_hostname"]/value)[1]'
,
'nvarchar(max)'
)
as
action_client_hostname,
event_data.value (
'(event/action[@name="database_name"]/value)[1]'
,
'nvarchar(max)'
)
as
action_database_name,
event_data.value (
'(event/action[@name="nt_username"]/value)[1]'
,
'nvarchar(max)'
)
as
action_nt_username,
event_data.value (
'(event/action[@name="session_id"]/value)[1]'
,
'int'
)
as
action_session_id,
event_data.value (
'(event/action[@name="sql_text"]/value)[1]'
,
'nvarchar(max)'
)
as
action_sql_text
from
xevents
go
if exists (
select
*
from
sys.server_event_sessions
where
name
=
'sqlws_xevents_attention'
)
drop
event session sqlws_xevents_attention
on
server
go
create
event session sqlws_xevents_attention
on
server
add
event sqlserver.attention (
action
(sqlserver.client_app_name, sqlserver.client_hostname, sqlserver.database_name, sqlserver.nt_username, sqlserver.session_id, sqlserver.sql_text)
where
duration > 5000 )
add
target package0.ring_buffer
with
(event_retention_mode = ALLOW_SINGLE_EVENT_LOSS, memory_partition_mode = NONE)
go
/*
alter
event session sqlws_xevents_attention
on
server state = start
go
--Execute your workload
with
xevents (event_name)
as
(
select
event.value (
'(@name)[1]'
,
'varchar(max)'
)
as
event_name
from
((
select
cast
(xest.target_data
as
xml)
as
target_data
from
sys.dm_xe_sessions
as
xes
inner
join
sys.dm_xe_session_targets
as
xest
on
(xes.address = xest.event_session_address)
where
xes.
name
=
'sqlws_xevents_attention'
and
xest.target_name =
'ring_buffer'
)
as
td
cross
apply target_data.nodes (
'//event[@name="attention"]'
)
as
x (event))
)
select
event_name,
count
(*)
from
xevents
group
by
event_name
go
select
*
from
sqlws_xev_attention
go
alter
event session sqlws_xevents_attention
on
server state = stop
go
*/
|
调优建议
对于连接耗时，当然务必要找到具体原因，是网络问题还是验证问题；对于查询超时，多为语句性能问题导致，如阻塞、未使用合理的索引、输出数据量太大等原因。对于临时解决问题，可以在连接配置里、或在程序里的语句级参数属性调大配置值。当然应及时找出问题的根源并解决。
本文转自UltraSQL51CTO博客，原文链接：http://blog.51cto.com/ultrasql/1864004 ，如需转载请自行联系原作者
