© 2008 Quest Software, Inc. ALL RIGHTS RESERVED. Perfmon and Profiler 101

About Me: Brent Ozar SQL Server Expert for Quest Software Former SQL DBA Managed >80tb SAN, VMware Dot-com-crash experience Specializes in performance tuning

Today’s Agenda The Honda Civic and the Nissan GT-R Metrics, Trace, Mitigations A New Secret Weapon Resources and Q&A

If You Don’t Need to Go Fast… From

But The Faster You Want To Go

The More You Have To Measure

Windows “Check Engine” Light

And If You Wanna Go Fast:

Two Approaches to Detection Exceptions Monitoring: Check Engine Proactive Monitoring: Detailed Gauges

Where Do We Start? Hardware Windows SQL Server Tables, Indexes Query

Capture Metrics With Perfmon Performance Monitor, aka Perfmon Ships with all Windows versions Polls any server from your desktop Pulls performance metrics Writes them to a file Requires some OS permissions Does not include alerts or analytics

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Memory Counters Memory – Available Mbytes Paging File - % Usage SQLServer:Buffer Manager – –Buffer cache hit ratio –Page life expectancy SQLServer:Memory Manager – Memory Grants Pending

Storage Metrics: Physical Disk % Disk Time Avg. Disk Queue Length Avg. Disk sec/Read Avg. Disk sec/Write Disk Reads/sec Disk Writes/sec

CPU Metrics Processor - % Processor Time System – Processor Queue Length SQLServer:General Statistics – User Connections (not CPU, just “other”)

16 The Raw Output: CSV Files

17 Adding Analytical Formulas

18 That’s a Lot of Zeroes!

19 Sorting High to Low

What To Look For, In Order System – Processor Queue Length Memory – Available Mbytes Lock pages in memory!

What To Look For Next Disk metrics on the page file drive Disk metrics on the log file drive Disk metrics on the data file drive Disk metrics on the TempDB drive

Got Everything on One Drive? Narrow it down with the DMV sys.dm_io_virtual_file_stats

What If We Could Data Mine It?

Table Analysis Tools For The Cloud

Detecting Categories of Load

Capture Queries with a Trace

Columns to Capture What’s Going On Text Data DatabaseID and/or DatabaseName Login Name Host Name Application Name What The Impact Was CPU Reads Writes Duration Start Time End Time

Profiler’s Results: A Trace Table

Order By Duration Descending

Casting and Grouping

Another Cloud Analytics Candidate

Another Way: Perf Dashboard

Correlate Metrics & Trace Show a cause and effect relationship Fields to mentally “join” on: –Date/Time ranges –CPU –Reads/Writes –Duration

Sample Problem #1 Metrics tell us: –Very high disk queue lengths on data drive Trace tells us: –Report queries doing table scans w/o indexes –Many scheduled reports run simultaneously

Ways We Can Mitigate It Add covering indexes Modify existing indexes Run reports serially, not all at once Add hard drives to the data file array Add memory to cache scanned tables

Sample Problem #2 Metrics tell us: –Page file drive queue lengths average >20 –Page file use averages >1% –Available memory averages <200mb –Buffer cache hit ratio and page life expectancy are high Trace tells us: –No unusual queries

Memory Configuration Server: 4gb ram OS: 1gb SQL: 3gb App: 1gb

Ways We Can Mitigate It Add memory and enable AWE/PAE Add memory and upgrade to 64-bit Reduce SQL’s min/max memory sizes Move the app to its own server

Sample Problem #3 Metric looks OK, but every 15 minutes: –Long drive queues on the log file drive –Page life expectancy drops near zero –Network traffic jumps Trace tells us: –Transaction log backups are running

Ways We Can Mitigate It Stop doing log backups Put the databases in simple mode Add drives to the transaction log array Throttle the transaction log backups

Sample Problem #4 Metrics tell us: –CPU average is high –Disk, memory look OK Trace tells us: –Queries are using cursors –Operating on individual records, not sets

How We Can Mitigate It Change cursor to set-based query Buy really fast processors Spend a lot on licensing

Wrapping Things Up Double-check the event log first Don’t get overwhelmed: focus with the Metric – Trace – Mitigation process Show a clear cause and effect Use cloud-based BI to get an edge

Resources On The Web My posts about Perfmon and analytics: Excel Table Analysis Tools for the Cloud: SQL Server community: SQLServerPedia.com