Architecting a Highly Available Infrastructure:An Overview

SLN187

Mark MilowMike DiPetrillo

Agenda

Why?SolutionsQ&A

Quick Stats2004 Gartner study found an average of $42,000 per hour of downtime

Average network experiences 175 hours of downtime a year (98% availability)That’s $7.35 million in lost revenue each yearAn increase to 99% means only $3.68 millionThat’s $3.67 million you can spend on DR

Quick Math: Amazon.comRevenue in 2001: $3.1B/year with 7774 employeesRevenue Per Hour: ~$350,000If outage effects 90% of revenue: ~$320,000Assume average annual salary is $85,000$656M/year or $12.5M/week for all staff@ 50 Hours/week: ~ $250,000 per hourIf outage effects 80% of employees: ~$200,000Total is $520,000 per hour of downtime

Why and for What?Different levels

Planned disasters (hurricanes, etc.)Unplanned disasters (power outage, tornadoes, etc.)

High availabilityPlan for local (inside the datacenter) failures

Disaster recoveryPlan for regional (the datacenter is gone) failures

Definitions

MTR: Mean Time to RecoverCTR: Cost To RecoverTiers: Levels of Recovery Options

Helpful HintsTier data

Break data into tiers of different MTR commitsNetworking

Plan how to get your network to fail with the dataPeople

Don’t plan on people flying to remote sitesAutomate

Automate as much of the failover as possible

Local High Availability

Local High AvailabilityFeatures

Standard clustering agentsSolutions for non-cluster aware appsStateful and non-stateful failoverFailover and fail-back

Product vendorsLegato, Microsoft, Veritas, Steeleye, Linux

Deployment scenariosPhysical to virtualVirtual to virtualPoor man’s

Primary Server ESX ServerFailover Server

4U, 8-way Rackmountwith ESX Server

MS Exchange Windows 2000

File / PrintWindows NT

Intranet App Server on Windows 2000

Data

Data

Data

1U, 2-way Rack

MS Exchange Windows 2000

1U, 2-way Rack

File / PrintWindows NT

1U, 2-way Rack

Intranet App Server on Windows 2000

Shared disks, arrays or

SAN storage

Physical to Virtual Clustering

Virtual to Virtual Clustering

ESX Server 2VM4

HP 4-wayRackmountDell 4-way

Rackmount

ESX Server 1

Shareddisks

arrays, orSAN storage

VM5

VM6

VM1 VM2

VM3

VM4 VM5

VM6

VM1 VM2

VM3

ON ON

VM1VM2

VM3

VM5VM6

VM4

OFF OFFON

Poor Man’s Clustering

Local High Availability

ConsiderationsCostMTRNumber of virtual machinesDisk space

BenefitsOut-of-the-box solutionStateful failoverInexpensiveFor any application

OS Based Solutions

OS Based SolutionsFeatures

Regular agentsVery similar to physical environmentEfficiencies from virtual machine architecture

Product vendorsLegato, Symantec, Veritas

Deployment scenariosPhysical to virtualVirtual to virtualTrunk of Car

Tape Array

Backup Server

Physical to Virtual

Tape Array

Backup Server

Virtual to Virtual

Trunk of Car

OS Based Solutions

ConsiderationsCostNumber of virtual machinesBandwidthDisk space

BenefitsStandard solutionNo learning curveGreat reduction in agent cost

Host Based Solutions

Host Based SolutionsFeatures

“Agent” based, runs as a serviceFile/byte level replicationSynchronous and asynchronousFailover and fail-back

Product VendorsLegato, NSI Double-Take, NeverFail, Mimix

Deployment ScenariosPhysical to virtualVirtual to virtualMulti-node

Virtual to Virtual

Primary Site Failover Site

Virtual to Virtual

Primary Site Failover Site

Virtual to Virtual Multi-Node

Primary Site Failover Site

Virtual to Virtual Multi-Node

Primary Site Failover Site

Virtual to Virtual Multi-Node

Primary Site Failover Site

Host Based Solutions

ConsiderationsCostDistanceNumber of virtual machinesBandwidth

BenefitsOut-of-the-box solutionMaximum uptimeEase of use

SAN Based Solutions

SAN Based Solutions Features

SAN layered applicationsLUN SnapshotReplication/Mirroring

Block level replicationSynchronous and asynchronous

Products VendorsEMC, HP, IBM, Network Appliance

Deployment ScenariosPhysical to virtualVirtual to virtualHybrid

SAN: Virtual to Virtual

Failover SitePrimary Site

Host Agent For

Replication and Failover

Hybrid Mode Backup

Failover SitePrimary Site

SAN Replication

Host Agent For Virtual

Machine and Application

Failover

SAN Based SolutionsConsiderations

CostDistanceBandwidthDowntimeComplex configuration

BenefitsHigh performance CentralizationMultiple working copies

Questions