How to speed up .NET and SQL Server web

appsBart Read

Who am I?• Bart Read, Web, Database, and Mobile Performance Consultant• Previously worked for Red Gate• Contacts• E: bart@bartread.com• W: www.bartread.com• B: www.bartread.com/blog• T: @bart_read• GH: https://github.com/bartread

General Web Performance

http://www.bartread.com/2014/06/03/web-performance-how-fast-does-website-need-to-be/

Always measure! (But

it’s almost never the

code!)

Production Monitoring

Detailed Diagnostic Tools

Other Handy Ancillary Tools

A word of warning about SSMS

Read Erland Sommarskog’s post, “Slow in the application, fast in SSMS?”: http://www.sommarskog.se/query-plan-mysteries.html

Scenario 1The Slow Support Centre

Customer Support Centre

(MS Dynamics)

Grant Fritchey’s FREE eBook on execution plans:

http://www.red-gate.com/community/books/sql-server-execution-plans-ed-2

Tool: http://www.supratimas.com/

Scenario 2The Memory Leak in the eCommerce Site

eCommerce Site

(MS Dynamics)

Other technologies:- NServiceBus- Endeca

Scenario 3Locking, Blocking and Deadlocking

Locking, Blocking & Deadlocking

Concurrency• Object level concurrency• Row level concurrency

Transaction Isolation Levels• Read Uncommitted• Read Committed <- SQL Server default• Repeatable Read• Snapshot• Serializable

ACID

Locking pattern• Reads• A -> B -> C -> D -> A -> B -> C -> D -> E -> A …• Etc.

• Writes• A –> B -> C -> D -> E -> A -> B -> A -> B -> C -> D …• Etc.

Solutions• DEADLOCK_PRIORITY• http://msdn.microsoft.com/en-us/library/ms186736.aspx• SET DEADLOCK_PRIORITY LOW | NORMAL | HIGH

• Read Committed Snapshot Isolation• http://www.brentozar.com/archive/2013/01/implementing-snapshot-or-read-

committed-snapshot-isolation-in-sql-server-a-guide/

• Disciplined ordering of object access• Unit of Work Pattern

• Martin Fowler• http://martinfowler.com/eaaCatalog/unitOfWork.html

Scenario 4Networking

Stuart Cheshire, “It’s the latency, stupid” (1996): http://www.stuartcheshire.org/rants/latency.html

Fast/Slow Query

Query Frame

Result Set Frame

Virtual NIC Setting To Blame

Client-side Scenarios - General Observations• Payload• Chattiness/latency• CSS transitions and animations• Code execution time again becomes an issue• Garbage• High memory usage

Star Citadel: https://arcade.ly/games/starcastle

Other Scenarios• Indexes• Missing indexes• Maintenance• Statistics• NTEXT (etc.) preventing online rebuilds

• http://www.bartread.com/2014/09/17/convert-all-ntext-columns-to-nvarcharmax-sql-server/

• Stored procedures and cached execution plans• WITH RECOMPILE

Questions?E: bart@bartread.comW: www.bartread.comB: www.bartread.com/blogT: @bart_readGH: https://github.com/bartread

Red Gate coding challenge: http://www.red-gate.com/our-company/entrypage/coding-challenge