SQL Server Cluster Presentation


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SQL Server Cluster Presentation

  1. 1. SQL Server 2000 Clustering Jeff Dalton Extreme Logic January 8, 2003
  2. 2. Agenda <ul><li>Why Cluster </li></ul><ul><li>Cluster Concepts </li></ul><ul><li>Windows 2000 Cluster Technology </li></ul><ul><li>SQL Server 2000 Cluster Technology </li></ul><ul><li>Failover Cluster in Action </li></ul><ul><li>Best Practices and Resources </li></ul>
  3. 3. Improve Operational Excellence <ul><li>How much downtime can my company afford without losing productivity, profits, sales, etc.? </li></ul><ul><li>The goal of a highly available system is to provide continuous use of critical data and applications regardless of planned and unplanned interruption </li></ul><ul><li>Infamous “Five 9s” </li></ul><ul><li>How available is available and how much will it cost? </li></ul><ul><ul><li>Knowing the business need will help determine technology costs </li></ul></ul><ul><ul><li>The more you need, the more you will need to spend </li></ul></ul>
  4. 4. Failover Clusters; part of the solution!
  5. 5. Clusters Defined <ul><li>A cluster is a group of independent computers ( nodes ) that work together to run a common set of applications and provide the image of a single system ( virtual server ) to the client and application. The computers are physically connected by cables and programmatically connected by cluster software </li></ul><ul><li>Two different cluster models in the industry: </li></ul><ul><ul><li>Shared Nothing (the Microsoft Way) </li></ul></ul><ul><ul><ul><li>Only one node can own and access a single hardware resource at any time </li></ul></ul></ul><ul><ul><li>Shared Device </li></ul></ul><ul><ul><ul><li>Any node can access any hardware resource in the cluster as the Distributed Lock Manager ( DLM ) arbitrates access </li></ul></ul></ul>
  6. 6. Windows 2000 Clustering Technologies <ul><li>Server Cluster </li></ul><ul><ul><li>Intended primarily as a high availability technology to provide failover support for applications such as databases (SQL Server 2000), messaging systems and file/print services </li></ul></ul><ul><ul><li>2-node FAILOVER CLUSTERS in Advanced Server and 4-node in Datacenter Server </li></ul></ul><ul><ul><li>Primary focus of our talk ! </li></ul></ul><ul><li>Network Load Balancing (NLB) Cluster </li></ul><ul><ul><li>Load balances incoming IP traffic across clusters of up to 32 nodes </li></ul></ul><ul><ul><li>Enhances both availability and scalability of Internet server-based programs such as Web Servers </li></ul></ul>
  7. 7. Benefits of Windows 2000 Clustering <ul><li>High Availability (think Server Cluster) </li></ul><ul><ul><li>Designed to avoid Single Point of Failure (SPoF) </li></ul></ul><ul><ul><li>Ability of an application to continue operation with loss of single component </li></ul></ul><ul><ul><li>Ownership of resources automatically transferred to surviving server; users experience only a momentary pause in service </li></ul></ul><ul><li>Scalability (think NLB Cluster) </li></ul><ul><ul><li>Ability of an application to grow in size as user demand increases by adding additional processors and/or nodes </li></ul></ul><ul><ul><li>Scale Up and Scale Out </li></ul></ul><ul><li>Manageability </li></ul><ul><ul><li>Cluster Administrator </li></ul></ul><ul><ul><li>Single Point of Control (can be remote) </li></ul></ul><ul><ul><li>Cluster appears as a single-system image </li></ul></ul>
  8. 8. Server Cluster Logical View Client PCs Server A Server B Common Disk Array Heartbeat Virtual Server
  9. 9. Network Load Balancing Cluster Logical View <ul><li>No single point of failure </li></ul><ul><li>No performance bottleneck </li></ul><ul><li>No additional hardware needed </li></ul><ul><li>Grow incrementally as demand increases </li></ul><ul><li>Up to 32 nodes in a cluster </li></ul>NLB Virtual IP Address Internet/ intranet NLB Host NLB Host NLB Host NLB Host NLB Host
  10. 10. Server Cluster Terminology <ul><li>Node </li></ul><ul><ul><li>Individual computers that comprise a cluster </li></ul></ul><ul><ul><li>2 in Windows AS, 4 in Windows DCS </li></ul></ul><ul><li>Heartbeat </li></ul><ul><ul><li>Private Network between nodes in the cluster to check if node is alive </li></ul></ul><ul><li>External Networking </li></ul><ul><ul><li>At least one public network so that outside world can connect to the cluster </li></ul></ul><ul><li>Resource </li></ul><ul><ul><li>Managed Hardware or Software components (Disks, IP addresses, applications, databases) </li></ul></ul><ul><li>Resource Group </li></ul><ul><ul><li>Resource Group is the collection of logically related cluster resources that are treated as a unit during node operations </li></ul></ul>
  11. 11. Server Cluster Terminology 2 <ul><li>Common “Shared Nothing” Disk Array </li></ul><ul><ul><li>Collection of physical disks (SCSI RAID or Fibre Channel) that will be accessed by the cluster </li></ul></ul><ul><ul><li>Only one node can own a given resource at any given time </li></ul></ul><ul><li>Virtual Server (Key Concept!!!!) </li></ul><ul><ul><li>The outside world sees the Virtual Server (server name and IP address) as a single image system of the multiple nodes </li></ul></ul><ul><li>Quorum Resource/Drive </li></ul><ul><ul><li>Special and Required Common Resource - physical disk in the common cluster disk array that plays a critical role in cluster operations (form/join) </li></ul></ul><ul><li>Failover/Failback </li></ul><ul><ul><li>Act of moving from failed node(s) to surviving node(s) and back again (if needed) </li></ul></ul>
  12. 12. SQLServer 2000 Failover Clustering <ul><li>Feature of SQL Server 2000 Enterprise Edition </li></ul><ul><li>Automatic Failover and “Quick Restart” </li></ul><ul><ul><li>Not a scalability solution </li></ul></ul><ul><ul><li>Doesn’t obviate need for Database Disaster/Backup/Recovery </li></ul></ul><ul><li>Requires specialized hardware solutions </li></ul><ul><li>Clients will be disconnected on failure but can reconnect relatively quickly </li></ul><ul><ul><li>Still connect to the same server/IP Address </li></ul></ul><ul><li>Server/transaction recovery is automatic </li></ul><ul><ul><li>Because the data and transaction log files are failed over </li></ul></ul><ul><ul><li>Recovery from a failure looks like a normal server startup to the failed over server </li></ul></ul>
  13. 13. Other SQLServer 2000 HA Options <ul><li>Log Shipping </li></ul><ul><ul><li>New feature of SQL Server 2000 Enterprise Edition </li></ul></ul><ul><ul><li>Concept has been in use for a long time </li></ul></ul><ul><ul><ul><li>Transaction logs from a primary database and apply them to a secondary </li></ul></ul></ul><ul><ul><li>Great primary or secondary method even if you can’t afford failover clustering </li></ul></ul><ul><li>Replication </li></ul><ul><ul><li>Not the traditional method of HA – technology has been around for a long time </li></ul></ul><ul><ul><li>Sometimes better than log shipping for transactional consistency </li></ul></ul><ul><ul><li>Easy to replicate read-only data </li></ul></ul><ul><ul><li>Possibly more complex, additional resources </li></ul></ul><ul><ul><li>Uses – reporting, read only, possibly updates; partition data </li></ul></ul>
  14. 14. Failover Configurations <ul><li>Active-Passive </li></ul><ul><ul><li>SQL Server on “primary” instance running, secondary instance is idle until a failover </li></ul></ul><ul><li>Active-Active </li></ul><ul><ul><li>SQL Server is running on both servers in the cluster simultaneously with different databases </li></ul></ul><ul><ul><li>But they are independent of each other (no load balancing or data sharing) </li></ul></ul><ul><li>Active/Active/Active/Active on 4-node ! </li></ul><ul><li>NOTES </li></ul><ul><ul><li>In SQL 2000, these terms are “deprecated”, still popular though… </li></ul></ul><ul><ul><li>In SQL 2000, we use the term “SQL Virtual Server Instances” </li></ul></ul>
  15. 15. Failover Cluster in Action Server A Server B Disk cabinet A Disk cabinet B Heartbeat Cluster management SQL Server SQL Server
  16. 16. Bang ! Server A Server B Disk cabinet A Disk cabinet B Heartbeat Cluster management SQL Server SQL Server
  17. 17. All’s Clear ! Server A Server B Disk cabinet A Disk cabinet B Heartbeat Cluster management SQL Server SQL Server ?
  18. 18. Failback (if needed) Server A Server B Disk cabinet A Disk cabinet B Heartbeat Cluster management SQL Server SQL Server
  19. 19. Rolling Upgrades Resource1 Resource2 1
  20. 20. Rolling Upgrades Upgrade Resource2 Resource1 Resource2 1 Resource1 2
  21. 21. Rolling Upgrades Upgrade Resource2 Resource1 Resource2 1 Upgrade Resource1 Resource2 3 Resource1 2
  22. 22. Rolling Upgrades Upgrade Resource2 Resource1 Resource2 1 Resource1 Resource2 Upgrade Resource1 Resource2 3 Resource1 2 4
  23. 23. Best Practices and Resources
  24. 24. Implementation Tips <ul><li>Plan, plan, plan! </li></ul><ul><li>Plan shared disk space </li></ul><ul><li>Don’t skimp on hardware </li></ul><ul><li>Test, test, test! </li></ul><ul><li>Cluster failover </li></ul><ul><li>Hardware failures </li></ul><ul><ul><li>Network cards and cables </li></ul></ul><ul><ul><li>Shared disk arrays and cables </li></ul></ul><ul><ul><li>Entire node shutdowns </li></ul></ul><ul><li>SQL Server and application failures </li></ul>
  25. 25. Best Practices and Resources <ul><li>Be prepared to READ a lot </li></ul><ul><ul><li>SQL2K BOL </li></ul></ul><ul><ul><ul><li>Great place to start for common questions, installation order, deployment considerations, supported configurations, etc. </li></ul></ul></ul><ul><ul><li>SQL2K Resource Kit </li></ul></ul><ul><ul><ul><li>Must Read Part 4 Chapters 12-16 </li></ul></ul></ul><ul><ul><li>Presentation Resources Page </li></ul></ul><ul><li>Microsoft supports only validated cluster configurations (Hardware Compatibility List) </li></ul><ul><li>Special Considerations </li></ul><ul><ul><li>Ensure that each server is a member of the same domain </li></ul></ul><ul><ul><li>Only one MSDTC per Cluster </li></ul></ul><ul><ul><li>SQL 2000 Analysis service (OLAP) </li></ul></ul><ul><ul><li>SQL Mail (MAPI is not cluster aware) </li></ul></ul><ul><ul><li>Nothing should go on the Quorum Drive </li></ul></ul>
  26. 26. More Resources <ul><li>Web Resources </li></ul><ul><li>Windows 2000 Clustering Technologies Home Page (Technical and Introductory Overviews) http://www.microsoft.com/windows2000/technologies/clustering/default.asp </li></ul><ul><li>Step-by-Step Guide to Installing Cluster Service http://www.microsoft.com/windows2000/techinfo/planning/server/clustersteps.asp </li></ul><ul><li>Building a Highly Available Database Cluster http://msdn.microsoft.com/library/techart/d5clustering.htm </li></ul><ul><li>Best Practices for End-to-End High Availability http://www.microsoft.com/ technet/avail/bestprac/bestprac.htm </li></ul><ul><li>  </li></ul><ul><li>Microsoft Support Articles Q243218, INF: Installation Order for SQL Server 2000 Enterprise Edition on Microsoft Cluster Server http://support.microsoft.com/support/kb/articles/Q243/2/18.ASP </li></ul><ul><li>Q260758, INF: Frequently Asked Questions - SQL Server 2000 - Failover Clustering http://support.microsoft.com/support/kb/articles/q260/7/58.asp </li></ul><ul><li>Q274446, INF: Upgrade to a SQL Server 2000 Failover Solution Recommended for All non-SQL Server 2000 Virtual Servers http://support.microsoft.com/support/kb/articles/Q274/4/46.ASP </li></ul><ul><li>Microsoft Newsgroups microsoft.public.sqlserver.clustering   </li></ul><ul><li>Other Resources </li></ul><ul><li>Microsoft Support Webcasts </li></ul><ul><li>Windows Clustering: An Overview of Microsoft Clustering Technologies http://support.microsoft.com/servicedesks/Webcasts/WC012100/WCBLURB012100.ASP </li></ul><ul><li>Introduction to Microsoft SQL Server 2000 Clustering http://support.microsoft.com/servicedesks/webcasts/wc051001/wcblurb051001.asp </li></ul>