SQLSaturday 393- May 16, 2015- Redmond, WA Diagnosing Performance with Wait Statistics SQLSaturday 393- May 16, 2015- Redmond, WA Principal Database Architect at DB Best Technologies www.dbbest.com Former Principal DBA at Outerwall, Inc Former Sr. Product Consultant with Idera Software Former Program Manager for SQL Server Certified Master program in Microsoft Learning Former Sr. Production DBA / Operations Engineer at Microsoft (CSS) Microsoft Certified Master: SQL Server 2008 / MCSM Charter: Data Platform Co-founder of the SQL PASS Security Virtual Chapter MCITP: Database Developer: SQL Server 2005 and 2008 MCITP: Database Administrator: SQL Server 2005 and 2008 MCSE: Data Platform MVP 2014 Co-author of Pro SQL Server 2008 Mirroring Former Idera ACE (Advisors & Community Educators) 2 time host of T-SQL Tuesday Guest Professor at SQL University, summer 2010, spring/summer 2011 Speaker at SQL PASS Summit 2010, 2011, and 2012 including a pre-con in 2012 Speaker/Pre-con at SQLRally 2012 13+ years working with SQL Server Writer for SQL Server Pro (formerly SQL Server Magazine) Member: Mensa Dog picture: Maggie and Woody SQLCruise instructor: Seattle to Alaska 2012 Speaker at SQL Server Intelligence Conference in Seattle 2012 Blog: http://www.sqlsoldier.com Twitter: http://twitter.com/SQLSoldier Robert L Davis Principal Database Architect robertd@dbbest.com @SQLSoldier www.dbbest.com

Robert L Davis Principal Database Architect at DB Best Technologies Greater Seattle Area | Information Technology and Services Past: Blog: Twitter: LinkedIN: Principal DBA at Outerwall, Inc. P.M. SQL Server Master Certification Program at Microsoft Sr. Database Administrator at Microsoft www.SQLSoldier.com @SQLSoldier www.linkedin.com/in/robertldavis Principal Database Architect at DB Best Technologies www.dbbest.com Former Principal DBA at Outerwall, Inc Former Sr. Product Consultant with Idera Software Former Program Manager for SQL Server Certified Master program in Microsoft Learning Former Sr. Production DBA / Operations Engineer at Microsoft (CSS) Microsoft Certified Master: SQL Server 2008 / MCSM Charter: Data Platform Co-founder of the SQL PASS Security Virtual Chapter MCITP: Database Developer: SQL Server 2005 and 2008 MCITP: Database Administrator: SQL Server 2005 and 2008 MCSE: Data Platform MVP 2014 Co-author of Pro SQL Server 2008 Mirroring Former Idera ACE (Advisors & Community Educators) 2 time host of T-SQL Tuesday Guest Professor at SQL University, summer 2010, spring/summer 2011 Speaker at SQL PASS Summit 2010, 2011, and 2012 including a pre-con in 2012 Speaker/Pre-con at SQLRally 2012 13+ years working with SQL Server Writer for SQL Server Pro (formerly SQL Server Magazine) Member: Mensa Dog picture: Maggie and Woody SQLCruise instructor: Seattle to Alaska 2012 Speaker at SQL Server Intelligence Conference in Seattle 2012 Blog: http://www.sqlsoldier.com Twitter: http://twitter.com/SQLSoldier

Diagnosing Performance with Wait Statistics “Find the problem, FIX IT. Identify another problem, FIX IT. Repeat as necessary.” ~ Keenan Thompson (Saturday Night Live)

Diagnosing Performance with Wait Statistics Medical approach to troubleshooting

Diagnosing Performance with Wait Statistics Medical approach to troubleshooting Baseline vital statistics Performance counters DMV stats

Diagnosing Performance with Wait Statistics Medical approach to troubleshooting Baseline vital statistics Performance counters DMV stats Recheck vital statistics and compare

Diagnosing Performance with Wait Statistics Medical approach to troubleshooting Baseline vital statistics Performance counters DMV stats Recheck vital statistics and compare Find deviations from the norm

Diagnosing Performance with Wait Statistics Medical approach to troubleshooting Baseline vital statistics Performance counters DMV stats Recheck vital statistics and compare Find deviations from the norm Read more: http://bit.ly/LsoN5x

Diagnosing Performance with Wait Statistics Baseline for Performance

Diagnosing Performance with Wait Statistics Baseline for Performance Processor(*)\% Processor Time PhysicalDisk\Avg. Disk sec/Read PhysicalDisk\Avg. Disk sec/Write Memory\Pages/sec Memory\Available Bytes SQLServer:Buffer Manager\Page life expectancy SQLServer:GeneralStatistics\Processes Blocked SQLServer:Access Methods\Full Scans/sec SQLServer:SQL Statistics\Batch requests/sec SQLServer:Buffer Manager\Lazy writes/sec SQLServer:Buffer Manager\Buffer Cache Hit Ratio SQLServer:Databases (*)\Transactions/sec

Diagnosing Performance with Wait Statistics Troubleshooting Slow Queries

Diagnosing Performance with Wait Statistics Troubleshooting Slow Queries Wait statistics

Diagnosing Performance with Wait Statistics Troubleshooting Slow Queries Wait statistics sys.dm_os_wait_stats sys.dm_os_waiting_tasks sys.dm_exec_requests sys.dm_exec_sessions sys.dm_exec_query_plan() sys.dm_exec_sql_text()

Diagnosing Performance with Wait Statistics Troubleshooting Slow Queries sys.dm_os_wait_stats

Diagnosing Performance with Wait Statistics Troubleshooting Slow Queries sys.dm_os_wait_stats Cumulative since last restart or reset

Diagnosing Performance with Wait Statistics Troubleshooting Slow Queries sys.dm_os_wait_stats Cumulative since last restart or reset DBCC SQLPERF ('sys.dm_os_wait_stats', CLEAR);

Diagnosing Performance with Wait Statistics Troubleshooting Slow Queries sys.dm_os_wait_stats Cumulative since last restart or reset DBCC SQLPERF ('sys.dm_os_wait_stats', CLEAR); Total waits on server

Diagnosing Performance with Wait Statistics Troubleshooting Slow Queries sys.dm_os_wait_stats Cumulative since last restart or reset DBCC SQLPERF ('sys.dm_os_wait_stats', CLEAR); Total waits on server Take a delta to see how they are changing

Diagnosing Performance with Wait Statistics Troubleshooting Slow Queries sys.dm_os_wait_stats Cumulative since last restart or reset DBCC SQLPERF ('sys.dm_os_wait_stats', CLEAR); Total waits on server Take a delta to see how they are changing signal_wait_time_ms Time from when the waiting task has its resource until it starts running Waiting on CPU thread

Diagnosing Performance with Wait Statistics Troubleshooting Slow Queries sys.dm_os_waiting_tasks

Diagnosing Performance with Wait Statistics Troubleshooting Slow Queries sys.dm_os_waiting_tasks Tasks currently waiting on a resource

Diagnosing Performance with Wait Statistics Troubleshooting Slow Queries sys.dm_os_waiting_tasks Tasks currently waiting on a resource wait_duration_ms

Diagnosing Performance with Wait Statistics Troubleshooting Slow Queries sys.dm_os_waiting_tasks Tasks currently waiting on a resource wait_duration_ms wait_type

Diagnosing Performance with Wait Statistics Troubleshooting Slow Queries sys.dm_os_waiting_tasks Tasks currently waiting on a resource wait_duration_ms wait_type blocking_session_id

Diagnosing Performance with Wait Statistics Troubleshooting Slow Queries sys.dm_os_waiting_tasks Tasks currently waiting on a resource wait_duration_ms wait_type blocking_session_id resource_description

Diagnosing Performance with Wait Statistics Troubleshooting Slow Queries sys.dm_exec_requests

Diagnosing Performance with Wait Statistics Troubleshooting Slow Queries sys.dm_exec_requests Currently active requests Shows wait stats too! session_id request_id – for parallel tasks start_time status – suspended = waiting command database_id blocking_session_id wait_type wait_time last_wait_type – if not currently waiting wait_resource

Diagnosing Performance with Wait Statistics Troubleshooting Slow Queries sys.dm_exec_sessions

Diagnosing Performance with Wait Statistics Troubleshooting Slow Queries sys.dm_exec_sessions Currently active sessions Shows client connection info Not all sessions have a request Has some performance stats cumulative over all requests for the entire session program_name is_user_process

Diagnosing Performance with Wait Statistics Troubleshooting Slow Queries sys.dm_exec_query_plan() Query plan from cache Requires plan_handle

Diagnosing Performance with Wait Statistics Troubleshooting Slow Queries sys.dm_exec_query_plan() Query plan from cache Requires plan_handle sys.dm_exec_sql_text() SQL text from cache Requires sql_handle or plan_handle Provides offset values to identify the currently executing statement in a batch

Diagnosing Performance with Wait Statistics SOS_SCHEDULER_YIELD

Diagnosing Performance with Wait Statistics SOS_SCHEDULER_YIELD SOS: SQLOS

Diagnosing Performance with Wait Statistics SOS_SCHEDULER_YIELD SOS: SQLOS SCHEDULER: manages worker threads onto CPU threads

Diagnosing Performance with Wait Statistics SOS_SCHEDULER_YIELD SOS: SQLOS SCHEDULER: manages worker threads onto CPU threads YIELD: Giving way to another

Diagnosing Performance with Wait Statistics SOS_SCHEDULER_YIELD SOS: SQLOS SCHEDULER: manages worker threads onto CPU threads YIELD: Giving way to another Waiting for another worker thread to yield the CPU thread

Diagnosing Performance with Wait Statistics PAGE_LATCH / PAGE_IO_LATCH

Diagnosing Performance with Wait Statistics PAGE_LATCH / PAGE_IO_LATCH PAGE: unit of data storage in SQL Server

Diagnosing Performance with Wait Statistics PAGE_LATCH / PAGE_IO_LATCH PAGE: unit of data storage in SQL Server IO: reading (I) and writing (O), in this case disk IO

Diagnosing Performance with Wait Statistics PAGE_LATCH / PAGE_IO_LATCH PAGE: unit of data storage in SQL Server IO: reading (I) and writing (O), in this case disk IO LATCH: Lightweight locking mechanism

Diagnosing Performance with Wait Statistics PAGE_LATCH / PAGE_IO_LATCH PAGE: unit of data storage in SQL Server IO: reading (I) and writing (O), in this case disk IO LATCH: Lightweight locking mechanism Waiting for a latch on a page in memory or a page on disk

Diagnosing Performance with Wait Statistics CXPACKET

Diagnosing Performance with Wait Statistics CXPACKET CX: Communication eXchange

Diagnosing Performance with Wait Statistics CXPACKET CX: Communication eXchange PACKET: unit of communication

Diagnosing Performance with Wait Statistics CXPACKET CX: Communication eXchange PACKET: unit of communication Parallelism is occurring

Diagnosing Performance with Wait Statistics NETWORK_IO

Diagnosing Performance with Wait Statistics NETWORK_IO NETWORK: External communication

Diagnosing Performance with Wait Statistics NETWORK_IO NETWORK: External communication IO: Reading (I) and writing (O)

Diagnosing Performance with Wait Statistics NETWORK_IO NETWORK: External communication IO: Reading (I) and writing (O) SQL is writing faster than the client is reading

Diagnosing Performance with Wait Statistics PREEMPTIVE_OS_xxxxx

Diagnosing Performance with Wait Statistics PREEMPTIVE_OS_xxxxx PREEMPTIVE: Non-yielding

Diagnosing Performance with Wait Statistics PREEMPTIVE_OS_xxxxx PREEMPTIVE: Non-yielding OS: Operating System

Diagnosing Performance with Wait Statistics PREEMPTIVE_OS_xxxxx PREEMPTIVE: Non-yielding OS: Operating System xxxxx: The OS operation or API being called Non-yielding shell out to the Operating System

Diagnosing Performance with Wait Statistics PREEMPTIVE_OS_AUTHENTICATIONOPS

Diagnosing Performance with Wait Statistics PREEMPTIVE_OS_AUTHENTICATIONOPS PREEMPTIVE: Non-yielding OS: Operating System

Diagnosing Performance with Wait Statistics PREEMPTIVE_OS_AUTHENTICATIONOPS PREEMPTIVE: Non-yielding OS: Operating System AUTHENTICATIONOPS: The OS operation or API being called

Diagnosing Performance with Wait Statistics PREEMPTIVE_OS_AUTHENTICATIONOPS PREEMPTIVE: Non-yielding OS: Operating System AUTHENTICATIONOPS: The OS operation or API being called, a group of API calls related to authentication

Diagnosing Performance with Wait Statistics PREEMPTIVE_OS_AUTHENTICATIONOPS PREEMPTIVE: Non-yielding OS: Operating System AUTHENTICATIONOPS: The OS operation or API being called, a group of API calls related to authentication Non-yielding shell out to the OS to perform authentication operations

Diagnosing Performance with Wait Statistics PREEMPTIVE_OS_VERIFYSIGNATURE

Diagnosing Performance with Wait Statistics PREEMPTIVE_OS_VERIFYSIGNATURE PREEMPTIVE: Non-yielding OS: Operating System VERIFYSIGNATURE: The OS operation or API being called

Diagnosing Performance with Wait Statistics PREEMPTIVE_OS_VERIFYSIGNATURE PREEMPTIVE: Non-yielding OS: Operating System VERIFYSIGNATURE: The OS operation or API being called Let’s Look it Up

Diagnosing Performance with Wait Statistics PREEMPTIVE_OS_VERIFYSIGNATURE PREEMPTIVE: Non-yielding OS: Operating System VERIFYSIGNATURE: The OS operation or API being called Verifies if a digital signature matches the signature used to encrypt data

Diagnosing Performance with Wait Statistics PREEMPTIVE_OS_VERIFYSIGNATURE PREEMPTIVE: Non-yielding OS: Operating System VERIFYSIGNATURE: The OS operation or API being called Let’s Look it Up

Diagnosing Performance with Wait Statistics Resources http://www.sqlsoldier.com/wp/tag/performance-optimization http://www.sqlsoldier.com/wp/tag/troubleshooting http://sqlserverperformance.wordpress.com/?s=DMV http://sqlloadgenerator.codeplex.com

Diagnosing Performance with Wait Statistics Q & A

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