microsoft secrets

Abstract

This white paper discusses the approach used to convert the Hotmail web server farm from UNIX to Windows 2000, and the reasons the features and techniques were chosen. It will focus primarily on the planners, developers, and system administrators. The purpose of the paper is to provide insight for similar deployments using Windows 2000. We will discuss the techniques from the viewpoint of human engineering as well as software engineering.

Early results from the conversion, which was limited to the front-end web servers, are:

n Windows 2000 provides much better throughput than UNIX.

n Windows 2000 provides slightly better performance than UNIX.

n There is potential, not yet realized, for stability of individual systems to be equal to that of UNIX. The load-balancing technology ensures that the user experience of the service is that stability is as good as it was before the conversion.

n As this paper will show, while the core features of Windows 2000 are able to run the service, its administrative model is not well suited to the conversion.

The observations related here are derived from experience gained at a single site. More work would be needed to establish whether they are representative.
Version History

Version
Date
Author
Comments

Draft 1
8/8/2000
David Brooks
Initial draft for review

Draft 2
8/22/2000
David Brooks
Rewrote abstract; added a section on initial experiences; other updates

Table of Contents

Abstract 1

Version History. 1

Table of Contents. 1

Project Overview. 3

Critical Features of Hotmail as a . COM Site. 4

Advantages of UNIX. 6

Problems of Windows. 7

Strengths of Windows. 9

Hotmail Architectural Decisions. 10

Project constraints. 10

Installation Methodology Conserved. 10

Conversion to ISAPI 10

Load Balancing Technology. 11

System Creation, Mastering and Installation. 12

OS installation and configuration. 12

IIS configuration. 13

Tuning and hardening the system. . 13

Use of Active Directory. 14

Users in AD. 14

Computer systems in AD. 14

Application Installation and Update. 15

Application update styles. 15

Application update techniques. 15

Intellimirror 15

Distribution mechanism and format 16

Monitoring and Logging. 16

Network Operations Center 16

Autonomous monitoring. 16

Logging. 17

Ad-hoc Maintenance. 17

Converting the UNIX Administrator 18

Conclusions. 19

Project Overview

M?crosöft acquired Hotmail at the end of 1997 as a going concern. The service’s creators had defined a two-layer architecture built around various UNIX systems:

n Front end web servers, built with dual Pentium systems on racked motherboards, running Apache on FreeBSD (a configuration with no need to install licensed software)

n Back end file stores, built with Sun Enterprise 4500 servers, running Solaris 2.6 (Sun’s UNIX) and with all user data stored on RAID arrays, accessed using very simple filing semantics

n Incoming mail listeners, built on Sun Sparc 5 processors, and interacting directly with the back end

n Name/password verification engines, build on Enterprise 4500 servers

n Member Directory, built on PCs with NT and SQL

The conversion of the Hotmail web servers to Windows is an ongoing project with several rationales. The team was hoping for better utilization of the existing hardware resources.