Cisco Datacenter Disaster Recovery

7/28/2019 Cisco Datacenter Disaster Recovery

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2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 1

Data CenterDisaster Recovery

KwaiSengConsulting Systems Engineer


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2006 Cisco Systems, Inc. All rights reserved. 2

Agenda Data CenterThe Evolution

Data Center Disaster RecoveryObjectives

Failure Scenarios

Design Options

Components of Disaster Recovery

Site SelectionFront End GSLB

Server High AvailabilityClusteringData Replication and SynchronizationSAN Extension

Data Center Technology Trends

Summary


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The Evolution of Data Centers


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Data Center Evolution

1960 1980 2000 2010

BusinessAg

ility

Networked DataCenter Phase

Mainframes

Terminal

Client/Server

ComputeEvolution

NetworkEvolution

Network

OptimizationInternet

Computing

ContentNetworking

Data CenterContinuousAvailability

Data CenterConsolidation

Data CenterVirtualization

TCP/IP

Thin Client: HTTP

1. Consolidation

2. Integration

3. Virtualization

4. High Availability

Data Center

Networking


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N-TierApplications

DB Servers

App Servers

Web Servers

Mainframe OperationsIP Comm.

Front EndNetwork

Application/ServerOptimization

ContentSwitch

Cache

Todays Data Center

Integration of Many Systems and Services

Tape FCSAN

RAID

StorageNetwork

NAS

FC

Switch

VSANs

Scalable Infrastructure

DC Storage NetworksDistributed Data Centers

Application and Server Optimization

Data Center Security

Security

Firewall

IDS

ResilientIP

Metro NetworkDWDM/SONET/Ethernet

FCSwitch

Secondary Data Center

MAN/Internet

DR Data Center

FCSwitch

WAN/

Internet


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PrimaryData Center

SecondaryData Center

App A App B App A App C

FC FC

What Is Distributed Data Center?

Data Replication


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Distributed Data Centers

Required by disaster recovery and businesscontinuance

Avoid single, concentrated data depositary

High availability of applications and data access

Load balancing together with performance scalability

Better response and optimal content routing: proximityto clients


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PrimaryData Center



FC FC

Front-End IP Access Layer

Content RoutingSite Selection


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PrimaryData Center



FC FC

Application and Database Layer

Content SwitchingLoad Balancing

Server ClusteringHigh Availability


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PrimaryData Center



FC FC

Backend SAN Extension

Storage and OpticalData Replicationand Transporting


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Data Center Disaster

Recovery


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Agenda Introduction to Data CenterThe Evolution

Data Center Disaster Recovery

Objectives

Failure Scenarios

Design Options



Server High AvailabilityClusteringData Replication and SynchronizationSan Extension


Summary


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Disaster Recovery

Recovery of data and resumption of serviceEnsuringbusiness can recover and continueafter failure or disaster

Ability of a business to adapt, change and continuewhen confronted with various outside impacts

Mitigating the impact of a disaster


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Disaster Recovery

What It Means for Business

Zero Down Time Isthe Ultimate Goal

Business Resilience

Continued Operation ofBusiness During a Failure

Disaster Recovery

Protecting Data Through OffsiteData Replication

and Backup

Business Continuance

Restoration of BusinessAfter a Failure


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Disaster Recovery Planning

Business Impact Analysis (BIA)

Determines the impacts of various disasters to specific businessfunctions and company assets

Risk analysis

Identifies important functions and assets that are critical

to companys operations

Disaster Recovery Plan (DRP)

Restores operability of the target systems, applications,

or computing facility at the secondary data center afterthe disaster


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Disaster Recovery Objectives

Recovery Point Objective (RPO)The point in time (prior to the outage) in which systemand data must be restored to

Tolerable lost of data in event of disaster or failure

The impact of data loss and the cost associated withthe loss

Recovery Time Objective (RTO)The period of time after an outage in which the systems anddata must be restored to the predetermined RPO

The maximum tolerable outage time


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Recovery Point/Time vs. Cost

Smaller RPO/RTO

Higher $$$, replication,hot standby

Larger RPO/RTO

Lower $$$, tape backup/restore,cold standby

Time

DisasterStrikes

Time t1 Time t2

Systems Recoveredand Operational

Recovery Time

ExtendedCluster

ManualMigration

TapeRestore

Secs Mins Hours Days Weeks

$$$ Increasing Cost

Recovery Point

SynchronousReplication

SecsMinsHoursDays

AsynchronousReplication

PeriodicReplication

Tapebackup

time t0

$$$ Increasing Cost

Critical Data IsRecovered


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Objectives

Failure Scenarios

Design Options



Server High AvailabilityClustering

Data Replication and SynchronizationSan Extension


Summary


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Failure Scenarios

Network failure

Device failure

Storage failure

Site failure

Disaster Could Mean Many Types of Failure


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InternetService

Provider AService

Provider B

Network Failures

ISP failure

Dual ISP connections

Multiple ISP

Connection failure withinthe network

EtherChannel

Multiple route paths


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InternetService

Provider AService

Provider B

Device Failures

Routers, switches,FWs

HSRP

VRRP

Hosts

HA cluster

LB server farm

NIC teaming


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InternetService

Provider AService

Provider B

Storage Failures

Disk arrays

RAID

Disk controllers

Storage Replication

Site to Site Mirroring

Optimization


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InternetService

Provider AService

Provider B

Site Failures

Partial site failure

Application maintenance

Application migration

Application scheduledDR exercise

Complete site failure

Disaster


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Objectives

Failure Scenarios

Design Options






Summary


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Warm Standby

A data center that is equipped with hardware and

communications interfaces capable of providing backupoperating support

Latest backups from the production data center mustbe delivered

Network access needs to be activated

Application needs to be manually started


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Disaster RecoveryActive/Standby

PrimaryData Center


(Warm Standby)


FC FC

IP/Optical Network


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Hot Standby

A data center that is environmentally ready and hassufficient hardware, software to provide data

processing service with little down time

Hot backup offers disaster recovery, with little or nohuman intervention

Application data is replicated from the primary site

A hot backup site provides betterRTO/RPO than warmstandby but cost more to implement

Business continuance


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Disaster RecoveryActive/Standby

PrimaryData Center



FC FC

IP/Optical Network


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Active/Active DR Design

Multiple Tiers of Application

Presentation Tier

Application Tier

Storage Tier

InternetService

Provider AService

Provider B


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InternalNetwork

Active/Active

Application ProcessingActive/Standby

Database Processingor

Active/Activefor Different Application

InternalNetwork

Active/ActiveWeb Hosting

Active/Active Data Centers

InternetService

Provider A

ServiceProvider B


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Objectives

Failure Scenarios

Design Options




Data Replication and SynchronizationSAN Extension


Summary


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Site Selection Mechanisms

Site selection mechanisms depend on the technologyor mix of technologies adopted

forrequest routing:

1. HTTP redirect

2. DNS-based

3. L3 Routing with Route Health Injection (RHI)

Health of servers and/or applications needsto be taken into account

Optionally, other metrics (like load) can be measuredand utilized for a better selection


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HTTP RedirectionTraffic Flow

http://www2.cisco.com/

http://www1.cisco.com/

http://www.cisco.com/

1.GE

T/HTT

P/1.1

Host:ww

w.cisc

o.com

2.HT

TP/1.1302

Moved

Locatio

n:www2.c

isco.c

om

3. GET/HTTP/1.1Host:www2.cisco.com

HTTP/1.1200OK

K

eepaliv

es


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DNS-Based Site SelectionTraffic Flow

Client

DNS Proxy

Data Center 1

http://www.cisco.com/

Root Name Server for/ AuthoritativeName Server for .com

AuthoritativeName Servercisco.com

AuthoritativeName Server

www.cisco.com

Keepaliv

es

1

2

3 4

56

78

9

10

Kee

palives

Data Center 2

UDP:53

TCP:80


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Route Health InjectionImplementationClient BClient A

Router 13Router 11

Router 12

Router 10

Location BPreferred Location for

VIP x.y.w.z

Location ABackup Location for

VIP x.y.w.z

Very High Cost

Low Cost


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Site Selection Summary

SitePersistence

Convergence

Yes

No

NoWithin Secs

DNS Cache

No

YesActive/StandbyRHI

YesActive/ActiveDNS

NoActive/ActiveHTTP

Re-Direct

App HealthVisibility

Redundancy

Mode


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Objectives

Failure Scenarios

Design Options






Summary


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Cluster Overview

Load Balancing Cluster: multiplecopies of the same application

against the same data set,usually read only

High Availability Cluster:multiple copies of applicationthat requires access to a

common data depository, usuallyread and write

Clustering provides benefits foravailability, reliability, scalability,

and manageability

Application Servers

Web Servers

Database Servers


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High Availability Cluster Design Public Network : Client

/Application requests

Private Network :Interconnection betweennodes

Storage Disk : Sharedstorage array, NAS orSAN

OS

ClusterEnabler

ClusterSoftware

APP


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HA Cluster Application ViewActive/standby

Standby takes over when active fails

Two-node or multi-node

Active/activeDatabase requests load balanced all nodes

Lock mechanism ensures data integrity

Shared everything

Each node mounts all storage resources

Provides a single layout reference system for allnodes

Shared nothingEach node mounts only its semi-private storage

Data stored on the peer systems storage isaccessed via the peer-peer communication

Node1 Node2


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Geo-Cluster: Cluster That Span MultipleData Centers

Geo-Clusters Considerations

Node1 Node2

LocalDatacenter

RemoteDatacenter

WAN

Disk ReplicationSynchronous or Asynchronous

2 x RTT

Challenges:

Split brain

L2 heart-beats

Storage


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HA Cluster Challenges : Split-Brain

Split-brain : Active nodesconcurrently accessing thesame disk, leads to datacorruption

Resolution : Use a Quorum, atie breaker for gaining accessto the disk

Node1 Node2

Data Corruption


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Layer 2 Heartbeats

Extended L2 Network :L2 adjacency requiredfor nodes heartbeat.

Extending VLAN acrosssite is hazardous

Resolution : L3Capability for ClusterHeartbeat. EoMPLS tocarry L2 hearbitsacross DR sites.

Node1 Node2

LocalDatacenter

RemoteDatacenter

WAN

Disk Replication

Synchronous or Asynchronous

Public Layer 2 Network

Private Layer 2 Network


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Storage Disk Zoning

Storage Zoning : Takingover of storage diskarray when active nodefails.

Resolution : Clustersoftware to communicatewith the Cluster Enabler.

Instructs the Disk Array toperform an failover whenfailure is detected.

Node1 Node2

Extended SAN

sym1320 sym1291

StandbyActive

WD

WDRW

RW


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Objectives

Failure Scenarios

Design Options






Summary


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Storage for Applications Presentation tier

Unrelated small data files commonly stored on

internal disksManual distribution

Application processing tierTransitional, unrelated data

Small files residing on file systems

May use RAID to spread data over multiple disks

Storage tier

Large, permanent data files or raw dataLarge batch updates, most likely real time

Log and data on separate volumes


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Replication: Modes of Operation Synchronous

All data written to local and remote arrays before I/O is

complete and acknowledged to host

Asynchronous

Write acknowledged and I/O is complete after write to localarray; changes (writes) are replicated to remote arrayasynchronously

Speed of Light = 3 x 108m/s (Vacuum) 3.3s/km

Speed through Fiber c 5s/km

2 RTT per write I/O = 20s/km

Synchronous vs Asynchronous Trade-


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Synchronous

Impact to ApplicationPerformance

Distance Limited (AreBoth Sites Within the

Same Threat Radius)No Data Loss

Asynchronous

No ApplicationPerformance Impact

Unlimited Distance (SecondSite Outside Threat Radius)

Exposure to PossibleData Loss

Synchronous vs. Asynchronous Trade-

Off

Maximum tolerable distance ascertained by assessing

each application

Cost of data loss

Enterprises Must Evaluate the Trade-Offs


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Data Replication with DB Example

Control files identify other filesmaking up the database and

records content and state ofthe db

Datafile is only updatedperiodically

Redo logs record db changesresulting from transactions

Used to play back changes thatmay not have been written to

datafile when failure occurred

Typically archived as they fill tolocal and DR site destinations

ControlFiles

Datafiles Redo LogFiles

Identify

RecordChanges To

DB name

Creation date

Backup

performed Redo log

time period

Datafile state

Table spaces

Indexes

Data dictionary

Database changes



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(Cont.)

Database restored to state at time of failure(time t1) by:

1. Restoring control files and datafiles from last

hot backup (time t0)2. Sequentially replaying changes from subsequent redo

logs (archived and online)changes made betweentime t0 and t1

Hot Backup ofDatafiles andControl Files

Taken at Time t0

t0

Time

t1

Failure or Disaster Occursat Time t1

Media failure (e.g., disk)

Human error (datafile deletion)

Database corruption

Online RedoLogs

Archived Redo Logs

. . . . . . . . .



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(Cont.)

Mixture of Sync and Async Replication TechnologiesCommonly Used

Usually only redo logs sync replicated to remote site

Archive logs created from redo log and copied when redo log switches

Point in Time (PiT) copies of datafiles and control files copied periodically (e.g.,nightly)

Redo Logs (Cyclic)Redo Logs (Cyclic)Copy of Every

Committed Transaction

Archive Logs

SynchronouslyReplicated

for Zero Loss

Replicated/Copied

Primary Site Secondary Site

Replicated/Copied

Pointin Time

Copy TakenWhen DBQuiescent

Database

DatabaseCopy atTime t0

DatabaseCopy atTime t0

Earlier DBBackups

Archive Logs

SANExtensionTransport


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HighDensity

MultilayerSAN

Director

Internet

High

DensityMultilayer

LANSwitch

Data Center Interconnection Options

Back-EndApplication

Servers

Enterprise-ClassStorage Arrays

IntrusionDetection

ServerLoad

Balancing

ContentCaching

StatefulFirewalls

Front-EndApplication

Servers

SONET/SDH

DWDM/CWDM

IP/Metro E

High

DensityMultilayer

SANDirector

High

DensityMultilayer

LANSwitch

IntrusionDetection

ServerLoadBalancing

StatefulFirewalls

ContentCaching

Back-EndApplication

Servers

Enterprise-ClassStorage Arrays

Front-EndApplication

Servers

Internet


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Cisco Data Center Vision

Centralization andstandardization to lowercosts, improve efficiency

and uptime

Centralization andstandardization to lowercosts, improve efficiency

and uptime

CONSOLIDATIONCONSOLIDATION

VIRTUALIZATIONVIRTUALIZATIONLANWAN

MAN

LANWAN

MAN

SANSAN

StorageNetworkStorageNetwork

DataNetwork

DataNetwork

AUTOMATIONAUTOMATION

StorageNetworkCompute

EnterpriseApplicationsEnterprise

Applications

StorageStorage

NetworkNetwork

ComputeCompute

Business PoliciesOn-Demand

Service Oriented

Business PoliciesOn-Demand

Service OrientedManagement of resources

independent of underlyingphysical infrastructure to

increase utilization,efficiency and flexibility

Management of resources

independent of underlyingphysical infrastructure to

increase utilization,efficiency and flexibility

Dynamic provisioning andautonomic Information

Lifecyle Management (ILM)to enable business agility

Dynamic provisioning andautonomic Information

Lifecyle Management (ILM)to enable business agility

IntelligentInformation

Network

IntelligentInformation

Network

ServerFabric

Network

ServerFabric

Network

HPCCluster

GRID

HPCCluster

GRID


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Summary


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What we have talk so far? DR and its Business Objectives

Define budget, Technical solution

Management Buy In

DR is a process

Components of a Data Center

Multi Tier ArchitectureFront-end, Application, Backend Database

Techniques in Data Center Disaster Recovery

HTML Re-Direction/GSS/RHI

Clustering

SAN extension

Trends in Data Center Technology

Todays Data Centers


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y

Require an Architectural Approach to

Protect with Business ResilienceTighten security

Improve business continuance Optimize with Consolidation

Improve operational efficiencyand resource utilization

Lowercomplexity and costof ownership

Grow towards Services-orientedInfrastructure

Align virtualized resourceswith business demands

Automate infrastructure to responddynamically


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The Big PictureThe Cisco Data CenterThe EmergingData CenterArchitecture

MultiprotocolGateway Services

ENTERPRISETAPE STORAGE

ENTERPRISEDISK STORAGE

MAINFRAMECONNECTIVITY

TOPSPINFAMILY

Catalyst 6500Family

Enterprise

NAS Storage

Blade

Servers

UNIX/Windows

Servers

SERVERFABRIC

SWITCHING

SSL Termination

VPN Termination

Firewall Services

Intrusion Detection

Server Balancing

Server FarmSwitching

MDS 9000Family

Virtual Private

ServerFabric #1

Virtual Private

Blade ServerFabric #3

Virtual Private

ServerFabric #2

ENTERPRISE SANSWITCHING

Embedded IntelligentNetwork Services

Embedded IntelligentVirtualization Services

Server VirtualizationVFrame

V

Low Latency RDMA

Services

Virtual I/O

Clustering

Fabric Routing Svcs

Data Replication Svcs

Storage Virtualization

Virtual Fabrics (VSANs)Embedded Intelligent

Storage Services

ENTERPRISEGRID

Grid/Utility Computing

NAS UNIXWIN


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Whats Next?

A Security Strategy to Protect the Data Center

Understands the vulnerabilities, and apply the relevant mitigations

Leverage on Ciscos Technology to

Optimize the Server Resources

Reducing TCO for DRsVirtualization to maximize resource invested

Grow DC infrastructure, enabling Business Agility

Automating computing resources provisioningSpeed of deploying new services


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Q and A


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Cisco Datacenter Disaster Recovery

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