Building Scalable And High Performance Web Applications on IIS 6.0 And ASP.NET Rishi Kothari

Agenda What is new in IIS 6.0 ASP.NET Performance Tips & Tricks

What is new in IIS 6.0

ASP.NET Performance Tips & Tricks

Me.About() What do I do: U2U Training Standard Microsoft MOC curriculum Specialized Microsoft curriculum written by U2U U2U.BIZ Coaching & Consultancy Services on the full range of Microsoft Development Tools .Net Development SQL Server, SharePoint Portal Server, … Microsoft Regional Director independent developers and architects chosen for their leadership in their local technology circles

What do I do:

U2U

Training

Standard Microsoft MOC curriculum

Specialized Microsoft curriculum written by U2U

U2U.BIZ

Coaching & Consultancy Services on the full range of Microsoft Development Tools

.Net Development

SQL Server, SharePoint Portal Server, …

Microsoft Regional Director

independent developers and architects chosen for their leadership in their local technology circles

After Windows Server 2003 installation Where is my Web Server ? This Windows Server 2003 thing doesn't work, let’s switch back to Windows 2000 But wait: IIS 6.0 not installed by default Once installed IIS 6.0 only serves static content by default Security is much more locked down by default.

This Windows Server 2003 thing doesn't work, let’s switch back to Windows 2000

But wait:

IIS 6.0 not installed by default

Once installed

IIS 6.0 only serves static content by default

Security is much more locked down by default.

IIS 6.0 Architecture

Rearchitecting IIS Why do it - Current Challenges Availability – need 99.999% uptime Apps can still run in INETINFO on IIS5, which can affect web server reliability App isolation comes at a cost Perf vs. Reliability Can’t isolate everything! IISRESET = Heavy Hammer Resets connections

Availability – need 99.999% uptime

Apps can still run in INETINFO on IIS5, which can affect web server reliability

App isolation comes at a cost

Perf vs. Reliability

Can’t isolate everything!

IISRESET = Heavy Hammer

Resets connections

Rearchitecting IIS A review of IIS5 TCP/IP kernel user WinSock 2.0 DLLHost.EXE ISAPI Extensions DLLHost.EXE ISAPI Extensions INETINFO.EXE Metabase ISAPI Filters and Extensions DLLHost.EXE ISAPI Extensions INETINFO.EXE Metabase ISAPI Filters and Extensions

Rearchitecting IIS A New Architecture for IIS6 GOAL: enable complete app isolation from other web apps and core web server Web service in INETINFO split out to do this: HTTP.SYS: kernel mode listener and request router WAS: config and process manager Worker Processes: where web apps are processed Multiple Worker Processes WAS Worker Processes web app HTTP.SYS kernel

GOAL: enable complete app isolation from other web apps and core web server

Web service in INETINFO split out to do this:

HTTP.SYS: kernel mode listener and request router

WAS: config and process manager

Worker Processes: where web apps are processed

Multiple Worker Processes

Rearchitecting IIS HTTP.SYS What is it? Kernel-mode HTTP stack/listener Always running Supports listening on IPv4 and IPv6 protocols Reliability Features Doesn’t load or run any web apps including ISAPI filters and extensions Process routing based on URL Request queues: kernel-mode queuing Performance Features Kernel-mode response cache Text-based and binary logging

What is it?

Kernel-mode HTTP stack/listener

Always running

Supports listening on IPv4 and IPv6 protocols

Reliability Features

Doesn’t load or run any web apps including ISAPI filters and extensions

Process routing based on URL

Request queues: kernel-mode queuing

Performance Features

Kernel-mode response cache

Text-based and binary logging

Rearchitecting IIS W3 Worker Processes– W3WP.exe What is it? Main web processing core responsible for handling web requests Self–contained web server Contains all web request processing functionality Loads ISAPI’s – filters and extensions ASP, ASP .NET, FrontPage ® Server Extensions Delivers complete isolation from system components and other web apps

What is it?

Main web processing core responsible for handling web requests

Self–contained web server

Contains all web request processing functionality

Loads ISAPI’s – filters and extensions

ASP, ASP .NET, FrontPage ® Server Extensions

Delivers complete isolation from system components and other web apps

Rearchitecting IIS Web Admin Service (WAS) Application Manager Manages lifetime of Worker Processes Configuration Manager Configures HTTP.SYS No application code Ensures web server reliability External monitor of web application processes Ensures web application and service reliability Hosted in SVCHOST.exe Actually part of W3SVC

Application Manager

Manages lifetime of Worker Processes

Configuration Manager

Configures HTTP.SYS

No application code

Ensures web server reliability

External monitor of web application processes

Ensures web application and service reliability

Hosted in SVCHOST.exe

Actually part of W3SVC

Process Model Contrast IIS5 to IIS6 – Making it more robust HTTP.SYS TCP/IP Connections Requests User Mode Kernel Mode WAS ASP.NET Filters Worker Process ASP.NET Filters Worker Process ASP.NET Filters Worker Process INETINFO metabase AppPool 1 AppPool 2

IIS 6.0 Availability Enhancements

Application Pools Application Isolation in Processes Can create 1 or more application pools Each served by 1 or more processes. Each worker process serves only 1 pool. Reqs routed directly to pool by HTTP.sys Isolate apps based on: Site/Customer Functionality Reliability

Can create 1 or more application pools

Each served by 1 or more processes.

Each worker process serves only 1 pool.

Reqs routed directly to pool by HTTP.sys

Isolate apps based on:

Site/Customer

Functionality

Reliability

Recycling What is it and Why use it? What is it? Periodically restart applications based on: Uptime # of requests Scheduled time Memory consumption On-demand Why use it? Refresh apps to ensure availability Prevent bad apps from taking over the system No interruption in Service!!

What is it?

Periodically restart applications based on:

Uptime

# of requests

Scheduled time

Memory consumption

On-demand

Why use it?

Refresh apps to ensure availability

Prevent bad apps from taking over the system

No interruption in Service!!

Recycling Overlapping Recycle kernel user Ready for Recycle Shut down WAS HTTP.SYS Old Worker Process ISAPI Exts & Filters Web Proc. Core DLL New Worker Process ISAPI Exts & Filters Web Proc. Core DLL Request startup ready Request

Health Detection Crash Detection & Rapid Fail Protection WAS detects process crash/AV’s On failure Publish event to event log Check “crash count” If (Crash count > Max Crashes in time limit) Disable app pool Else start new process if demand Rapid Fail Protection Only allow x crashes in y minutes Return 503’s when invoked

WAS detects process crash/AV’s

On failure

Publish event to event log

Check “crash count”

If (Crash count > Max Crashes in time limit)

Disable app pool

Else start new process if demand

Rapid Fail Protection

Only allow x crashes in y minutes

Return 503’s when invoked

ASP.NET Best Practices

ASP.Net & Windows Server 2003 .Net Framework delivered in the box ASP.NET will use the IIS6 process model when running in W3WP.exe Runs completely within W3WP.exe Takes advantage of complete process isolation and added health/reliability features Store ASP.NET’s session state externally Persist state through a recycle

.Net Framework delivered in the box

ASP.NET will use the IIS6 process model when running in W3WP.exe

Runs completely within W3WP.exe

Takes advantage of complete process isolation and added health/reliability features

Store ASP.NET’s session state externally

Persist state through a recycle

Logical/Physical Design Best Practices

Logical Design Design your applications using logical 3-Tier Design Practices: Pages (.aspx) and User Controls (.ascx) Reusable Biz & Data Classes in in dir (.vb + .cs) Data within a SQL Database Design your Web application so that it can be distributed across a Web farm Your code shouldn’t assume that a client will always return to the same machine Be careful of assumptions regarding statics and application state

Design your applications using logical 3-Tier Design Practices:

Pages (.aspx) and User Controls (.ascx)

Reusable Biz & Data Classes in in dir (.vb + .cs)

Data within a SQL Database

Design your Web application so that it can be distributed across a Web farm

Your code shouldn’t assume that a client will always return to the same machine

Be careful of assumptions regarding statics and application state

Physical Deployment Deploy your applications such that the pages and components run in same process Deploying onto remote servers connected via DCOM(COM+ Enterprise Services), Remoting or Web Services will almost always hurt your performance Leverage Web services only for application to application communication -- not intra app calls

Deploy your applications such that the pages and components run in same process

Deploying onto remote servers connected via DCOM(COM+ Enterprise Services), Remoting or Web Services will almost always hurt your performance

Leverage Web services only for application to application communication -- not intra app calls

3 Tier Deployment Numbers

Server Control Performance Recommendations

Server Controls Server controls provide a very clean programming model abstraction Recommended way to build ASP.NET pages Server controls do more rendering/postback work that old-style <%= %> code Should understand what this work is and optimize for it accordingly Net take: the more individual server controls on page, the more this overhead can be noticed Need to be especially aware of this w/ composite list controls that generate multiple controls per data row

Server controls provide a very clean programming model abstraction

Recommended way to build ASP.NET pages

Server controls do more rendering/postback work that old-style <%= %> code

Should understand what this work is and optimize for it accordingly

Net take: the more individual server controls on page, the more this overhead can be noticed

Need to be especially aware of this w/ composite list controls that generate multiple controls per data row

Control Rendering Test

Caching Performance Best Practices

Design For Caching Cache, Cache, Cache – never do work you don’t need to do Leverage the built-in ASP.NET built-in caching features Output Caching Fragment Caching Cache API Recommendation: Specifically design your pages around these features – can lead to massive perf wins

Cache, Cache, Cache – never do work you don’t need to do

Leverage the built-in ASP.NET built-in caching features

Output Caching

Fragment Caching

Cache API

Recommendation:

Specifically design your pages around these features – can lead to massive perf wins

Output Caching Caches the static result of an ASP.NET page Declarative <%@ OutputCache %> directive Optional Output Cache APIs can also be called Caching Options: Duration Time item exists in the cache VaryByParam Varies cache entries by Get/Post params Name param, separate by semi-colons, supports * VaryByHeader Varies cache entries by Http header VaryByCustom Override method within Global.asax to custom vary by whatever you want (you control the cache key)

Caches the static result of an ASP.NET page

Declarative <%@ OutputCache %> directive

Optional Output Cache APIs can also be called

Caching Options:

Duration

Time item exists in the cache

VaryByParam

Varies cache entries by Get/Post params

Name param, separate by semi-colons, supports *

VaryByHeader

Varies cache entries by Http header

VaryByCustom

Override method within Global.asax to custom vary by whatever you want (you control the cache key)

Dynamic Kernel Caching GET http://www.acme.com/store/sproketcatalog.aspx Without Cache <%@ OutputCache Duration=&quot;10&quot; VaryByParam=&quot;none&quot; %> Request Response With Cache Request Response