Geek Sync I CSI for SQL: Learn to be a SQL Sleuth

© 2015 IDERA, Inc. All rights reserved.
Proprietary and confidential.
CSI FOR SQL
Learn to be an SQL Sleuth

2© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential.
AGENDA
 Objectives
 Methodology
 Performance Monitor
 Extended Events
 Bonus Diagnostic Queries
 Questions

OBJECTIVES
 Meet Service Level Agreements
 Get the most out of existing hardware
 Prevent unnecessary hardware purchases /
upgrades
 Spend $$ where it will make a difference
 Create a Baseline
 Be a Hero (or stay out of the Dog House)

AGENDA
 Objectives
 Methodology
 Extended Events
 Questions

Queries
Database
Other Software
Operating System
Hardware
METHODOLOGY
 Bottom Up
 Top Down
 Entire Ecosystem
 Triage Approach
to determine
where to focus
first
• Emergency Room Medical Approach
• Questions & Answers determine
entry point of your investigation
Top
Down
Bottom
Up

METHODOLOGY – IMMEDIATE ISSUE
 Medical Approach
• Chief Complaint
• History of Present Illness
• Past Medical History
• Past Family Social
• Physical Exam

 Chief Complaint
• Clarification
• “The System is Down!!!!”
− Nobody can work?
− Some people can’t work?
− One person can’t work?
− Some “thing” isn’t working?
• Verification
• Make sure what is being reported is actual factual
information.
• Does the claim agree with what you see happening
on the server?
• Emotional versus Rational

 History of Present Illness
• Who, Context, Timing, Location, Duration?
• AKA: Who, What, When, Where, How Long? 
We’re after the WHY.
 Example
• A complaint comes in that saving a reference
number for an order (what) takes more than 1
minute (how long).
• This began about 3 hours ago (when).
• It appears it is only happening in the order entry
application (where).
• Both users on local workstations and remote
users are reporting problems in this area (who).

 Past Medical History
• Is the problem new?
• When did the problem start?
• Has the server had issues before or recently?
• Any interesting history about the server you’d
like to share?
• “We had a drive failure about 3 weeks ago”
• “We had a consulting company remotely taking care
of this server until recently”
• “We applied SP2 for SQL 2012 last week”

 Past Family Social
• What other applications are on this server?
• Antivirus, Windows Indexing?, Windows Update?
Reporting Services? (on and on)
• How many instances of SQL are on the
server?
• How many databases? What are they?

 Physical Exam
• If Problem is Actively Happening
• Any Blocking?
− Head of Chain?
− What are they running?
• What’s Running Now and what do the
Waits say?
• Extended Event Capture
− Long Running Queries
− Wide Open with Focused Filtering and Short
Duration
• If Problem is Intermittent or Not
Obvious
• Perfmon Capture - PAL
• Diagnostic DMVs
• Extended Event Capture Job
• Long Running Queries
• Set Traps

AGENDA
 Objectives
 Methodology
 Extended Events
 Questions

PERFORMANCE MONITOR
 A few quick counters to spot check
• All counters accessible through
start/run/perfmonCounters to Quickly Spot Check When Eyebrows should
raise
Meaning
SQLServer:Buffer Manager:Page Life
Expectancy
< 300 Memory Pressure
SQLServer:Memory Manager: Target
Server Memory
Way less than you think
SQL should be getting
Incorrect Memory Config
Memory: AvailableMB > 30 OS may be starving
Physical Disk: Avg Disk/Sec Read &
Avg Disk Sec/Write
> .100 Disk is insufficient and/or
Memory insufficient.
Physical Disk: % Idle Time Low is bad. 0 means disk is
saturated
Disk is insufficient and/or
Memory insufficient.
Processor: % Processor Time > 80% consistently / usage
is not balanced
Processors insufficient
and/or Memory or Disk
insufficient.
Processor: % Interrupt Time Usually on Proc 0 only.
Should be < 5%
consistently.
Hardware Driver issue (out
of date, incorrect version,
corruption)

PERFORMANCE MONITOR
 Longer Term Counters to Collect and Review
• Can use sys.dm_os_performance_counters DMV to
query/collect these directly from SQL Server
SQL Server Specific Counters
sql server: sql statistics: batch
requests/sec
sql server: locks: avg wait time(ms)
sql server: sql statistics: sql
compilations/sec
sql server: general statistics: processes
blocked
sql server: sql statistics: sql re-
compilations/sec
sql server: buffer manager: page life
expectancy
sql server: sql statistics: user connections sql server: buffer manager: free pages
sql server: access methods: full scans/sec sql server: buffer manager: lazy writes/sec
sql server: access methods: index
searches/sec
sql server: memory manager: total server
memory (kb)
sql server: access methods: page
splits/sec
sql server: memory manager: target server
memory (kb)
sql server: locks: number of
deadlocks/sec
sql server: memory manager: memory grants
pending
sql server: locks: table lock

PERFORMANCE MONITOR
 Longer Term Counters to Collect and Review
SQL Server Specific Counters
process(sqlserver): % processor time physical disk: avg disk sec/read
processor: % processor time physical disk: avg disk sec/write
Processor: % interrupt time physical disk: disk reads/sec
memory: available mbytes physical disk: disk writes/sec
memory: page splits/sec physical disk: disk read bytes/sec
physical disk: disk write bytes/sec

PERFORMANCE MONITOR
 Use Counters Together not in Isolation
Bytes per Second
Disk Response Time
Server A
IOs Per Second

PERFORMANCE MONITOR
 PAL Tool for SQL
• Create an XML Template of important SQL
Counters
• Generates an HTML Report
• Graphs
• Explanations
• Links

AGENDA
 Objectives
 Methodology
 Extended Events
 Questions

EXTENDED EVENTS
 Completed Events Capture
• SQL_Batch_Completed
• RPC_Completed
• SP_Statement_Completed

EXTENDED EVENT FIELDS
SP_Statement_Completed SQL_Batch_Completed RPC_Completed
statement batch_text statement
source_database_id database_id database_id
transaction_id transaction_id transaction_id
line_number
nt_username nt_username nt_username
client_hostname client_hostname client_hostname
client_app_name client_app_name client_app_name
server_principal_name server_principal_name server_principal_name
session_id session_id session_id
duration duration duration
timestamp timestamp timestamp
logical_reads logical_reads logical_reads
physical_reads physical_reads physical_reads
writes writes writes
cpu_time cpu_time cpu_time
object_id
server_instance_name server_instance_name server_instance_name
name name name
object_name object_name
database_name database_name database_name
row_count row_count row_count

EXTENDED EVENTS APPROACHES
 Long Running Query
• Duration Filter > X Seconds
 Thousand Paper Cuts
• Wide Open Trace
• Very Short Duration
• Strong Filter
− Spid
− Hostname
− ApplicationName
 Gaps Between SQL Calls
• Wide Open Trace
• Very Short Duration
• Strong Filter
− Spid
− Hostname
− ApplicationName
• Look for silence between Completion of Stmt 1 and Start
of Stmt 2

AGENDA
 Objectives
 Methodology
 Extended Events
 Questions

BONUS DIAGNOSTIC QUERIES
 Blocking
• Find head of the blocking chain (spid)
• Sp_who2
− Eyeball it
− Copy/Paste to excel, sort and filter
− Write/Borrow something custom that does recursive SQL
• Google Sp_whoisactive by Adam Machanic
• Select * from master.dbo.sysprocesses
• Look to see what blocking spid is doing
• Dbcc inputbuffer(spid)
• Phonecall / Kill
• Post Mortem

BONUS DIAGNOSTIC QUERIES
Useful Queries
Desired_Indexes_last10mins.sql
Get_Proc_CPU_Qty_Last10secs.sql
Longest_Running_Queries_Right_Now.sql
Dmv_most_expensive_queries.sql
Dmv_top_100_sps_by_exec_qty.sql
Dmv_top_20_sps_by_cpu_pressure.sql
Dmv_top_20_sps_by_memory_pressure.sql
Dmv_top_20_sps_by_physical_io_pressure.sql
Dmv_top_20_sps_by_logical_writes.sql

AGENDA
 Objectives
 Methodology
 Extended Events
 Questions

THANKS!
Any questions?
You can find me at:
@sqlgirl
mindycurnutt@hotmail.com

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