Geek Sync I CSI for SQL: Learn to be a SQL Sleuth
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This document provides an overview of SQL diagnostics and performance monitoring strategies, including objectives to improve service levels and methodology for troubleshooting issues. It emphasizes understanding the overall ecosystem, utilizing performance monitors, extended events, and specific diagnostic queries to address SQL-related problems. Additionally, it offers guidance on immediate issues, effective performance metrics, and long-term monitoring strategies.
Geek Sync I CSI for SQL: Learn to be a SQL Sleuth
- 1. © 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. CSI FOR SQL Learn to be an SQL Sleuth
- 2. 2© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. AGENDA Objectives Methodology Performance Monitor Extended Events Bonus Diagnostic Queries Questions
- 3. 3© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. 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)
- 4. 4© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. AGENDA Objectives Methodology Performance Monitor Extended Events Bonus Diagnostic Queries Questions
- 5. 5© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. 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
- 6. 6© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. METHODOLOGY – IMMEDIATE ISSUE Medical Approach • Chief Complaint • History of Present Illness • Past Medical History • Past Family Social • Physical Exam
- 7. 7© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. METHODOLOGY – IMMEDIATE ISSUE 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
- 8. 8© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. METHODOLOGY – IMMEDIATE ISSUE 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).
- 9. 9© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. METHODOLOGY – IMMEDIATE ISSUE 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”
- 10. 10© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. METHODOLOGY – IMMEDIATE ISSUE 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?
- 11. 11© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. METHODOLOGY – IMMEDIATE ISSUE 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
- 12. 12© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. AGENDA Objectives Methodology Performance Monitor Extended Events Bonus Diagnostic Queries Questions
- 13. 13© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. 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)
- 14. 14© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. 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
- 15. 15© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. 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
- 16. 16© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. PERFORMANCE MONITOR Use Counters Together not in Isolation Bytes per Second Disk Response Time Server A IOs Per Second
- 17. 17© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. PERFORMANCE MONITOR PAL Tool for SQL • Create an XML Template of important SQL Counters • Generates an HTML Report • Graphs • Explanations • Links
- 18. 18© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. AGENDA Objectives Methodology Performance Monitor Extended Events Bonus Diagnostic Queries Questions
- 19. 19© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. EXTENDED EVENTS Completed Events Capture • SQL_Batch_Completed • RPC_Completed • SP_Statement_Completed
- 20. 20© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. 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
- 21. 21© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. 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
- 22. 22© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. AGENDA Objectives Methodology Performance Monitor Extended Events Bonus Diagnostic Queries Questions
- 23. 23© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. 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
- 24. 24© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. 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
- 25. 25© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. AGENDA Objectives Methodology Performance Monitor Extended Events Bonus Diagnostic Queries Questions
- 26. 26© 2015 IDERA, Inc. All rights reserved. Proprietary and confidential. THANKS! Any questions? You can find me at: @sqlgirl [email protected]