SQL Server 2000 ClusteringSQL Server 2000 Clustering

Jeff DaltonJeff Dalton

Extreme LogicExtreme Logic

January 8, 2003January 8, 2003

AgendaAgenda Why ClusterWhy Cluster Cluster ConceptsCluster Concepts Windows 2000 Cluster TechnologyWindows 2000 Cluster Technology SQL Server 2000 Cluster TechnologySQL Server 2000 Cluster Technology Failover Cluster in ActionFailover Cluster in Action Best Practices and ResourcesBest Practices and Resources

Improve Operational ExcellenceImprove Operational Excellence

How much downtime can my company afford How much downtime can my company afford without losing productivity, profits, sales, without losing productivity, profits, sales, etc.?etc.?

The goal of a highly available system is to The goal of a highly available system is to provide continuous use of critical data and provide continuous use of critical data and applications regardless of applications regardless of plannedplanned and and unplannedunplanned interruption interruption

Infamous “Five 9s”Infamous “Five 9s” How available is available and how much will How available is available and how much will

it cost?it cost? Knowing the business need will help determine Knowing the business need will help determine

technology coststechnology costs The more you need, the more you will need to The more you need, the more you will need to

spendspend

Failover Clusters; part of the Failover Clusters; part of the solution!solution!

Clusters DefinedClusters Defined A cluster is a A cluster is a groupgroup of independent of independent

computers (computers (nodesnodes) that work together to run ) that work together to run a common set of applications and provide a common set of applications and provide the image of a the image of a single systemsingle system ( (virtual servervirtual server) ) to the client and application. The computers to the client and application. The computers are are physically connectedphysically connected by cables and by cables and programmatically connectedprogrammatically connected by cluster by cluster softwaresoftware

Two different cluster models in the industry:Two different cluster models in the industry: Shared NothingShared Nothing (the Microsoft Way) (the Microsoft Way)

Only one node can own and access a single Only one node can own and access a single hardware resource at any timehardware resource at any time

Shared DeviceShared Device Any node can access any hardware resource in Any node can access any hardware resource in

the cluster as the Distributed Lock Manager the cluster as the Distributed Lock Manager ((DLMDLM) arbitrates access) arbitrates access

Windows 2000 Clustering Windows 2000 Clustering TechnologiesTechnologies

Server ClusterServer Cluster Intended primarily as a Intended primarily as a high availabilityhigh availability

technology to provide failover support for technology to provide failover support for applications such as applications such as databasesdatabases (SQL Server 2000), (SQL Server 2000), messaging systems and file/print servicesmessaging systems and file/print services

2-node FAILOVER CLUSTERS in Advanced Server 2-node FAILOVER CLUSTERS in Advanced Server and 4-node in Datacenter Serverand 4-node in Datacenter Server

Primary focus of our talk !Primary focus of our talk ! Network Load Balancing (NLB) ClusterNetwork Load Balancing (NLB) Cluster

Load balances incoming IP traffic across clusters Load balances incoming IP traffic across clusters of up to 32 nodesof up to 32 nodes

Enhances both availability and Enhances both availability and scalabilityscalability of of Internet server-based programs such as Web Internet server-based programs such as Web Servers Servers

Benefits of Windows 2000 Benefits of Windows 2000 ClusteringClustering

High Availability (think Server Cluster)High Availability (think Server Cluster) Designed to avoid Single Point of Failure (SPoF)Designed to avoid Single Point of Failure (SPoF) Ability of an application to continue operation Ability of an application to continue operation

with loss of single componentwith loss of single component Ownership of resources automatically transferred Ownership of resources automatically transferred

to surviving server; users experience only a to surviving server; users experience only a momentary pause in servicemomentary pause in service

Scalability (think NLB Cluster)Scalability (think NLB Cluster) Ability of an application to grow in size as user Ability of an application to grow in size as user

demand increases by adding additional processors demand increases by adding additional processors and/or nodesand/or nodes

Scale Up and Scale OutScale Up and Scale Out ManageabilityManageability

Cluster AdministratorCluster Administrator Single Point of Control (can be remote)Single Point of Control (can be remote) Cluster appears as a single-system imageCluster appears as a single-system image

Client PCsClient PCs

Server AServer A Server BServer B

Common Disk ArrayCommon Disk Array

HeartbeatHeartbeat

Virtual Server

Server ClusterServer ClusterLogical ViewLogical View

NLB HostNLB HostNLB HostNLB Host

NLB Virtual NLB Virtual IP AddressIP Address

NLB HostNLB Host NLB HostNLB Host NLB HostNLB Host

Internet/Internet/intranetintranetInternet/Internet/intranetintranet

Network Load Balancing ClusterNetwork Load Balancing ClusterLogical ViewLogical View

No single point of No single point of failurefailure

No performance No performance bottleneckbottleneck

No additional No additional hardware neededhardware needed

Grow incrementally as Grow incrementally as demand increasesdemand increases

Up to 32 nodes in a Up to 32 nodes in a clustercluster

Server Cluster TerminologyServer Cluster Terminology NodeNode

Individual computers that comprise a clusterIndividual computers that comprise a cluster 2 in Windows AS, 4 in Windows DCS2 in Windows AS, 4 in Windows DCS

HeartbeatHeartbeat Private Network between nodes in the cluster to check Private Network between nodes in the cluster to check

if node is aliveif node is alive External NetworkingExternal Networking

At least one public network so that outside world can At least one public network so that outside world can connect to the clusterconnect to the cluster

ResourceResource Managed Hardware or Software components (Disks, IP Managed Hardware or Software components (Disks, IP

addresses, applications, databases)addresses, applications, databases) Resource GroupResource Group

Resource Group is the collection of logically related Resource Group is the collection of logically related cluster resources that are treated as a unit during cluster resources that are treated as a unit during node operationsnode operations

Server Cluster Terminology 2Server Cluster Terminology 2 Common “Shared Nothing” Disk ArrayCommon “Shared Nothing” Disk Array

Collection of physical disks (SCSI RAID or Fibre Collection of physical disks (SCSI RAID or Fibre Channel) that will be accessed by the clusterChannel) that will be accessed by the cluster

Only one node can own a given resource at any given Only one node can own a given resource at any given timetime

Virtual Server (Key Concept!!!!)Virtual Server (Key Concept!!!!) The outside world sees the Virtual Server (server name The outside world sees the Virtual Server (server name

and IP address) as a single image system of the and IP address) as a single image system of the multiple nodes multiple nodes

Quorum Resource/DriveQuorum Resource/Drive Special and Required Common Resource - physical disk Special and Required Common Resource - physical disk

in the common cluster disk array that plays a critical in the common cluster disk array that plays a critical role in cluster operations (form/join)role in cluster operations (form/join)

Failover/FailbackFailover/Failback Act of moving from failed node(s) to surviving node(s) Act of moving from failed node(s) to surviving node(s)

and back again (if needed)and back again (if needed)

SQLServer 2000 SQLServer 2000 Failover ClusteringFailover Clustering

Feature of SQL Server 2000 Enterprise Feature of SQL Server 2000 Enterprise EditionEdition

Automatic Failover and “Quick Restart”Automatic Failover and “Quick Restart” Not a scalability solutionNot a scalability solution Doesn’t obviate need for Database Doesn’t obviate need for Database

Disaster/Backup/RecoveryDisaster/Backup/Recovery Requires specialized hardware solutionsRequires specialized hardware solutions Clients will be disconnected on failure but Clients will be disconnected on failure but

can reconnect relatively quicklycan reconnect relatively quickly Still connect to the same server/IP AddressStill connect to the same server/IP Address

Server/transaction recovery is automaticServer/transaction recovery is automatic Because the data and transaction log files are Because the data and transaction log files are

failed overfailed over Recovery from a failure looks like a normal server Recovery from a failure looks like a normal server

startup to the failed over serverstartup to the failed over server

Other SQLServer 2000 HA OptionsOther SQLServer 2000 HA Options Log ShippingLog Shipping

New feature of SQL Server 2000 Enterprise EditionNew feature of SQL Server 2000 Enterprise Edition Concept has been in use for a long timeConcept has been in use for a long time

Transaction logs from a primary database and Transaction logs from a primary database and apply them to a secondaryapply them to a secondary

Great primary or secondary method even if you Great primary or secondary method even if you can’t afford failover clusteringcan’t afford failover clustering

ReplicationReplication Not the traditional method of HA – technology has Not the traditional method of HA – technology has

been around for a long timebeen around for a long time Sometimes better than log shipping for Sometimes better than log shipping for

transactional consistencytransactional consistency Easy to replicate read-only dataEasy to replicate read-only data Possibly more complex, additional resourcesPossibly more complex, additional resources Uses – reporting, read only, possibly updates; Uses – reporting, read only, possibly updates;

partition datapartition data

Failover ConfigurationsFailover Configurations

Active-PassiveActive-Passive SQL Server on “primary” instance running, SQL Server on “primary” instance running,

secondary instance is idle until a failoversecondary instance is idle until a failover Active-ActiveActive-Active

SQL Server is running on both servers in the cluster SQL Server is running on both servers in the cluster simultaneously with different databasessimultaneously with different databases

But they are independent of each other (no load But they are independent of each other (no load balancing or data sharing)balancing or data sharing)

Active/Active/Active/Active on 4-node !Active/Active/Active/Active on 4-node ! NOTESNOTES

In SQL 2000, these terms are “deprecated”, still In SQL 2000, these terms are “deprecated”, still popular though…popular though…

In SQL 2000, we use the term “SQL Virtual Server In SQL 2000, we use the term “SQL Virtual Server Instances”Instances”

Failover Cluster in ActionFailover Cluster in Action

Server AServer A Server BServer B

Disk cabinet ADisk cabinet A

Disk cabinet BDisk cabinet B

HeartbeatHeartbeat

Cluster managementCluster management SQL ServerSQL ServerSQL ServerSQL Server

Bang !Bang !

Server AServer A Server BServer B

Disk cabinet ADisk cabinet A

Disk cabinet BDisk cabinet B

HeartbeatHeartbeat

Cluster managementCluster management SQL ServerSQL ServerSQL ServerSQL Server

All’s Clear !All’s Clear !

Server AServer A Server BServer B

Disk cabinet ADisk cabinet A

Disk cabinet BDisk cabinet B

HeartbeatHeartbeat

Cluster managementCluster management SQL ServerSQL Server

SQL ServerSQL Server?

Failback (if needed)Failback (if needed)

Server AServer A Server BServer B

Disk cabinet ADisk cabinet A

Disk cabinet BDisk cabinet B

HeartbeatHeartbeat

Cluster managementCluster management SQL ServerSQL ServerSQL ServerSQL Server

Resource1Resource1

Resource2Resource2

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Rolling UpgradesRolling Upgrades

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Resource2Resource2

11 Resource1Resource122

Rolling UpgradesRolling Upgrades

UpgradeUpgradeResource2Resource2Resource1Resource1

Resource2Resource2

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Resource1Resource1

Resource2Resource2

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Resource1Resource122

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Rolling UpgradesRolling Upgrades

UpgradeUpgradeResource2Resource2Resource1Resource1

Resource2Resource2

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Resource1Resource1

Resource2Resource2

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Resource1Resource122

Resource1Resource1

Resource2Resource2

44UpgradeUpgrade

Rolling UpgradesRolling Upgrades

Best Practices and ResourcesBest Practices and Resources

Implementation TipsImplementation Tips

Plan, plan, plan!Plan, plan, plan! Plan shared disk spacePlan shared disk space Don’t skimp on hardwareDon’t skimp on hardware Test, test, test!Test, test, test! Cluster failoverCluster failover Hardware failuresHardware failures

Network cards and cablesNetwork cards and cables Shared disk arrays and cablesShared disk arrays and cables Entire node shutdownsEntire node shutdowns

SQL Server and application failuresSQL Server and application failures

Best Practices and ResourcesBest Practices and Resources Be prepared to READ a lotBe prepared to READ a lot

SQL2K BOLSQL2K BOL Great place to start for common questions, Great place to start for common questions,

installation order, deployment considerations, installation order, deployment considerations, supported configurations, etc.supported configurations, etc.

SQL2K Resource KitSQL2K Resource Kit Must Read Part 4 Chapters 12-16Must Read Part 4 Chapters 12-16

Presentation Resources PagePresentation Resources Page Microsoft supports only validated cluster Microsoft supports only validated cluster

configurations (Hardware Compatibility List)configurations (Hardware Compatibility List) Special ConsiderationsSpecial Considerations

Ensure that each server is a member of the same Ensure that each server is a member of the same domaindomain

Only one MSDTC per ClusterOnly one MSDTC per Cluster SQL 2000 Analysis service (OLAP)SQL 2000 Analysis service (OLAP) SQL Mail (MAPI is not cluster aware)SQL Mail (MAPI is not cluster aware) Nothing should go on the Quorum DriveNothing should go on the Quorum Drive

More ResourcesMore Resources

Web ResourcesWeb Resources Windows 2000 Clustering Technologies Home Page (Technical and Introductory Windows 2000 Clustering Technologies Home Page (Technical and Introductory

Overviews)Overviews)http://www.microsoft.com/windows2000/technologies/clustering/default.asphttp://www.microsoft.com/windows2000/technologies/clustering/default.asp

Step-by-Step Guide to Installing Cluster ServiceStep-by-Step Guide to Installing Cluster Servicehttp://www.microsoft.com/windows2000/techinfo/planning/server/clustersteps.asphttp://www.microsoft.com/windows2000/techinfo/planning/server/clustersteps.asp

Building a Highly Available Database ClusterBuilding a Highly Available Database Clusterhttp://msdn.microsoft.com/library/techart/d5clustering.htmhttp://msdn.microsoft.com/library/techart/d5clustering.htm

Best Practices for End-to-End High AvailabilityBest Practices for End-to-End High Availabilityhttp://www.microsoft.com/technet/avail/bestprac/bestprac.htmhttp://www.microsoft.com/technet/avail/bestprac/bestprac.htm

   Microsoft Support ArticlesMicrosoft Support Articles

Q243218, INF: Installation Order for SQL Server 2000 Enterprise Edition on Microsoft Q243218, INF: Installation Order for SQL Server 2000 Enterprise Edition on Microsoft Cluster ServerCluster Serverhttp://support.microsoft.com/support/kb/articles/Q243/2/18.ASPhttp://support.microsoft.com/support/kb/articles/Q243/2/18.ASP

Q260758, INF: Frequently Asked Questions - SQL Server 2000 - Failover ClusteringQ260758, INF: Frequently Asked Questions - SQL Server 2000 - Failover Clusteringhttp://support.microsoft.com/support/kb/articles/q260/7/58.asphttp://support.microsoft.com/support/kb/articles/q260/7/58.asp

Q274446, INF: Upgrade to a SQL Server 2000 Failover Solution Recommended for All non-Q274446, INF: Upgrade to a SQL Server 2000 Failover Solution Recommended for All non-SQL Server 2000 Virtual ServersSQL Server 2000 Virtual Servershttp://support.microsoft.com/support/kb/articles/Q274/4/46.ASPhttp://support.microsoft.com/support/kb/articles/Q274/4/46.ASP

Microsoft NewsgroupsMicrosoft Newsgroupsmicrosoft.public.sqlserver.clusteringmicrosoft.public.sqlserver.clustering  

Other ResourcesOther Resources Microsoft Support WebcastsMicrosoft Support Webcasts Windows Clustering: An Overview of Microsoft Clustering Technologies Windows Clustering: An Overview of Microsoft Clustering Technologies

http://support.microsoft.com/servicedesks/Webcasts/WC012100/WCBLURB012100.ASPhttp://support.microsoft.com/servicedesks/Webcasts/WC012100/WCBLURB012100.ASP Introduction to Microsoft SQL Server 2000 Clustering Introduction to Microsoft SQL Server 2000 Clustering

http://support.microsoft.com/servicedesks/webcasts/wc051001/wcblurb051001.asphttp://support.microsoft.com/servicedesks/webcasts/wc051001/wcblurb051001.asp