The hardest part about website performance optimization is identifying the root cause. In this presentation, Bruce Chapman, Director of Cloud and Web Operations at DNN, shows you how to perform a comprehensive performance audit of your .NET website. You’ll learn how to uncover the causes of performance issues, and understand that improving performance is often straightforward once the root cause is identified.

1. How to do a Performance Audit of your
.NET Website
Bruce
Chapman

2. The Performance Audit
Common Scenario
• Live .NET Website
• Not running to full potential
• Key stakeholders want it ‘faster’
Performance Audit
• Look at each individual part
• Know which parts to improve
What we will cover:
• Breaking down overall performance of .NET Website
• Understanding tools and processes to discover problems
• Providing a report and recommendations

3. Common .NET Website Architecture
Html JS Client Side Files
ASP.NET Page .NET API
SQL Database
Each Tier needs to be checked
for performance issues

4. Our Example Site
Evoq 8.5 Build (DNN Platform Base)
Site has been modified to add in performance problems.
Home Page Products Page

5. Analysis Tool - NewRelic
Multiple Purpose Server/Site Monitoring Tool
• Add Agent to .NET Application
• Add Server Agent to Windows/IIS and SQL Server
Works by:
• Monitoring code in the .NET runtime
• Injecting a beacon into sampled page loads
• Monitoring system-level resources via Server Agents
Reports via NewRelic Website
• Embeddable Reports available
• Free and Paid tiers available

6. Analysis Tool – Microsoft Application Insights
Performance, Exception and Diagnostic Tool
• Add agent to .NET Application
• Create Account via Azure Portal
Works by:
• Tracking Http requests
• Browser tracking via injected code
• Exception log ingestion
• Server Performance Counters
Reports via Azure Portal
• Customized Reports
• Free tiers & pay for extra data points

7. Step 1 : Understand the Problem
NumberofAffectedPages
Number of Affected Users
Problem Impact
Site
Issue
Page
Issue
Specific
Issue

8. Understanding the Problem
Monitoring Software
• Overall site performance
• Compare response time / load
NewRelic : Apdex Score
• Samples data to provide score
• Ratio of Satisfied/Dissatisfied
• Page & App performance
Azure Application Insights
• Average Server Response Time
• Average Page Load Time
• Individual Request drill-down
• Performance Buckets
• Request Duration
• Responses by Operation (page/API)

9. Drill into the Problem – Identify Pages to Analyze
Page Specific Issues different to Site Issues
• High volume high performance can mask low volume low performance
Site Apdex
Home Page Apdex Product Page Apdex
High Volume,
Good Apdex
Low Volume,
Patchy Apdex

10. Analysis Tool : Page Load Time Chrome extension
• Simple Plug-in for Chrome
• Measures page load speed of sites
• Gives simple breakdown of load times
• Quick and Easy – gives instant feedback

11. Step 2 : Analyze Specific Page Performance
Quantify the performance of problem page
• Multiple page browse iterations (5-20)
• Copy results into Spreadsheet
• Check for consistency/inconsistency
Check some other pages
• Find the worst page to analyse
• Confirm assumptions of page vs site issue
Server Response vs Page DOM
• Look at the slowest part first
• Look for unusual issues like DNS
• Check for consistency (add to sheet)

12. Analysis Tool : WebPageTest.org
Free Service for testing
pages
• Choose connection type
• Run multiple tests
• Add in custom headers
Report:
• Scores page
• Shows individual
components
• Reports have permanent
URLs to save for tests

13. Understanding Web Page Test Results
• First Byte : Time taken for Browser to get first response
• Start Render : When the Browser receives enough data to render
• Document Complete : All resources are loaded
• Fully Loaded : Page is completely rendered
Home page clearly has a problem – further investigation needed

14. Record Page Speed Values
Keep the values from the page load test
• Comparison of First/Second request shows effectiveness of
caching
Add the statistics to the Performance Audit Report

15. Understanding Web Page Waterfall View
Waterfall View
• Sequential loading
• Colors show stages
of resource load
Used to Identify:
• Slow resources
• Blocking calls
• Bandwidth &
Memory
requirements
Impact of TTFB on
page load time

16. Step 3 : Analyze Server Side Performance
Server Side Performance : Making TTFB Faster
• ASP.NET Page Performance
• Database Performance
• API Performance (AJAX/SPA Code)
Key Questions
• ASP.NET Page Generation : Where is time being spent?
• API Calls : How fast are the API calls?
• Database Queries : How many, how long for?
• Server Load : How much CPU / Memory is used?

17. Analysis Tool – Glimpse
• Open Source .NET Analysis Platform
• Runs as a Diagnostics tool against server side code
• Installed as a Component on the Server

18. ASP.NET Page Performance
ASP.NET Pages – Request => [code happens] => Response
Key Questions :
• Where is time being spent? How can it run faster?
• How can we measure this in a production runtime environment?
Measurement Tool : Glimpse / Page Life Cycle

19. ASP.NET Page Tracing
• Glimpse can act as a tracing listener
• Install Glimpse as per instructions
• Add System.Diagnostics.Trace.WriteLine(“”) calls to suspect code
DoMyStuff();
Listener
Wrapper
Add trace to web.config

20. Reading Trace with Glimpse
Glimpse Trace Output
- Shows Trace Statements inserted
- Differential Time count shows slow
statements

21. Finding Slow Database Queries with Glimpse
Glimpse shows the DB Queries/Times
The ‘SQL’ tab lists the number of queries
and the execution time.
Sometimes requires several iterations to determine
slow queries – caching and query plans may cause
intermittent slow running.

22. Analysis Tool – SQL Server Profiler
SQL Server Trace ships with SQL Server
• Requires elevated permissions to connect
• Traces the execution of statements
• Best results by carefully setting filters – works well with strong
naming standards of Stored Procedures

23. Database Performance - NewRelic
Useful for Identifying Slow Procedures
• Measures time taken and individual avg response time
• Look for slow procedures running frequently : highest impact
• Does not identify slow procedures for individual requests
(unless SP only run on that request)

24. Record Slow Queries
Query text & Speed recorded in Performance Audit Report

25. Step 4 : Browser Resource Performance
Waterfall Results identify long-running or slow-loading resources:
Select slow
items for more
information

26. Finding Oversize and Broken Resources
Images / Videos / Large CSS files
• Slow Loading Time
• File Size
Look for redirects / 404 / 401 response codes
List large Resources

27. Step 5: Check for Site-wide Issues
• Check for issues which may be slowing down the server
• Not related to a specific page
• Hardware issues, software issues
• Exception Logs
Exception log from
Log4Net output

28. Analysis Tools - Server Resources
• Check Server Resources during running
Process Explorer (Sysinternals Suite)
• Inspect individual threads
• Identify memory leaks
Windows Task
Manager

29. Completed Performance Audit Report
Guide for reporting
and list of items to fix

30. Start Fixing the Site
•Prioritize by
•Performance Gain
•Ease of Fix
•Access to Skills
•Change one thing at a time
•Re-test to determine & document change
•Update Audit Report with new figures
•Repeat endlessly for continuous gains
Next Steps for fixing issues

31. After Fixing Example Site
1.5 seconds
Fixes Made
- Scale down images to reduce
size
- Fix 404 for broken resource
- Fix slow running SQL
Procedure
- Fix slow running .NET code
Improvement : 7 seconds

32. New WebPageTest Results
New TTFB : 255 ms
Reduced repeat requests
Reduced page size

33. Resources
NewRelic
http://www.newrelic.com
Application Insights
https://azure.microsoft.com/en-
us/services/application-insights/
Page Load Timer
https://github.com/alex-vv/chrome-
load-timer
Web Page Test
http://webpagetest.org/
Glimpse
http://getglimpse.com/
Process Explorer
https://technet.microsoft.com/en
-us/processexplorer
To learn more about our .NET CMS:
http://www.dnnsoftware.com