1. HPUX 와 오라클 DB 의 HA 아키텍처 구성 황 명 석 한국 HP / 2004.3.18 2004 MAR MC Seminar

2. Agenda 1. Parallel Hardware Architecture 2. Oracle RAC 성능 3. Oracle RAC 와 hp Cluster Type 4. Oracle RAC 의 TAF

3. Parallel Hardware Architecture

4. Tightly Coupled System Loosely Coupled System Massively Parallel System

5. Tightly Coupled System 다수의 CPU 가 memory 공유 각 CPU 는 common Bus 를 통해 shared memory access Performance 는 Memory Bus 의 Bandwidth 에 의해 결정 SMP System (Symmetric Multiple Process)

6. Loosely Coupled Systems Loosely Coupled systems (cluster) 의 shared disk 는 하드웨어 레벨에서 구현. Shared disk system 는 물리적으로 cluster node 간에 동일한 disk array 를 공유.

7. Shared Nothing Implementations - MPP – 각 노드는 하나 이상의 CPU 를 갖는다. – 메모리는 노드간에 공유하지 않는다. – High-speed interconnect 사용을 기반으로 한다. – File 의 I/O request 는 user program 에게 투명한 high-speed interconnect 를 통하여 remote disk 를 accessing 한다.

8. Oracle RAC 의 성능

9. e-Business 시대의 RAC 필요성  e-Business 요구사항  높은 가용성 (High Availability)  높은 확장성 (High Scalability)  높은 서비스품질 (High Quality Of Services)  시장의 확대 (Extend Market – Globalization)  DBA 생산성 향상  On-Line Management  Business intelligence  E-business 를 위한 개발 환경

10. Cache Fusion Architecture 완벽한 Cache Fusion – Cache-to-Cache 데이터 전송 – 공유 캐쉬는 느린 I/O 작 업을 줄인다. – 데이터는 고성능 interconnect 를 통해 다 른 노드에 직접 전송 확장성 제공

11. Oracle9 i RAC Scalability HP-UX 기반 Platform 에서의 테스트 결과

12. Oracle RAC 와 hp Cluster Type

13. HP ServiceGuard Cluster Protection Levels single cluster within single data center automatic failover single cluster same site, separate bldgs automatic failover single cluster same city, separate sites automatic failover multiple clusters different cities, different countries “Push-button” failover Local Cluster Campus Cluster Metro Cluster Continen tal Cluster Flexibility Functionality Distance

14. Local Cluster supported with 9i RAC Distances up to 500m with direct FC up to 11km with FC switches (500m to switch, 10km between switches) up to 25m with direct SCSI Single Cluster Automatic Failover Data Center 1 Storage RAC Node ANode B within single data center

15. Campus Cluster supported with 9i RAC Distances up to 10km with Oracle9i RAC with FC switch/hub up to 100km only with MC/SG (extended CampusCluster) with DWDM Single Cluster Automatic Failover Software Mirroring with HP MirrorDisk/UX Only 2 node cluster supported with RAC & SLVM, and 4 nodes supported with RAC & Veritas CVM. For all storage types Data Center 1Data Center 2 Storage RAC Node A MirrorUX Node B MirrorUX same site, separate buildings

16. Metro Cluster not supported with 9i RAC Distances for CA/SRDF ESCON, ca. 43km FC direct, ca. 500m FC switches, ca. 10km FC switches plus ultra long haul GBIC ca. 80km DWDM, ca. 100km Single Cluster Rapid, automatic site recovery without human intervention Storage Hardware Mirroring separate arbitrator for split brain situations Data Center 1Data Center 2 XP/EMC MC/SG Node ANode B Node C Arbitrator CA / SRDF same city, separate sites

17. Continental Cluster supported with 9i RAC Distances Unlimited distance between data centers! Separate Cluster Locate data centers at economically and/or strategically best locations “Push-button” failover across 1000s of km different cities, different countries Data Center 1Data Center 2 XP/EMC RAC Node A Node B XP/EMC RAC Node A Node B WAN

18. Oracle DataGuard supported with 9i RAC Distances no limitation for Oracle DataGuard RAC cluster in one data center Changes get propagated to second data center with Oracle DataGuard (formerly Automated Standby Database) disaster tolarant Data Center 1Data Center 2 Storage RAC Node A Node BNode C Storage Oracle DataGuard

19. Oracle9i Data Guard Log Data Flow Primary Site Simultaneous log writes to online logs and standby logs Standby Database LGWR Synchronous or Asynchronous Oracle Net transport Standby Site Standby Redo Log Files Online Log Files Managed Recovery Process Achieved Log Files ARCH Remote File System Optional Delayed Apply Valid Log Records Choose to affirm log writes to disk

20. Flexible Data Availability Modes Protection ModeRisk of Data LossProduction Impact Instant (Sync Log Writes) Zero (If only primary fails) High (Has Fallback Mode) Delayed (Archive Logs Only) High (Current Online Log Lost) Low Rapid (Asynchronous) Minimal Low (Async Log Writes) Guaranteed (Sync Log Writes) Zero (Handles Double Failures) High (No Fallback Mode)

21. Guaranteed Protection Mode Primary Site Production Database Standby Site Online Log Files LGWR Standby Redo Log Files Synchronous Network Transport Stalls primary if standby site down or unreachable

22. Instant Protection Mode Primary Site Production Database Fallback to Delayed Mode if standby down or unreachable Standby Site Online Log Files LGWR Standby Redo Log Files Synchronous Network Transport

23. Rapid Protection Mode Primary Server Production Database Log Writer returns control to primary after write to Network Standby Site LGWR Async. Net Transport Network Send Online Log Files Standby Redo Log Files

24. Delayed Protection Mode Primary Site Changes propagated to standby site when online logs fill Standby Site ARCH Archived Log Files Archived Log Files Full Online Log Files

25. Standby Database History 정리 Oracle Version 7.3 custom Standby Databases – Current Log 반영 불가 (Only transferred arch. files) Oracle8i Automated Standby – Read only databases, Managed recovery – Remote archiving Oracle8i Data Guard – Automation: Single command switchover and failover – OPS and OFS support Oracle9i Data Guard – Built in zero Data Loss capability (Current log 반영 ) – GUI interface integrated with OEM Oracle9i R2 Data Guard – Oracle9i Data Guard Logical Standby database – SQL apply instead of log – Query & Reporting enabled

26. Oracle RAC 의 Transparent Application Failover Oracle RAC 의 TAF

27. page 27 What do you want to avoid? Database connections are stateful, simple network failover is insufficient Even after a fast database recovery clients were forced to exit their application and reconnect to the database Very intrusive Work lost

28. page 28 Client Side Load Balancing Clients connect to instance using random method (uses address list in tnsnames.ora) Node 1 rac2 instance lsnr2 9iRAC Database rac1 instance lsnr1 Node 2 Network Client 1 Client 2 Client 3 Client n

29. page 29 Listener Load Balancing Listeners balance load using CPU/user load Node 1 rac2 instance lsnr2 9iRAC Database rac1 instance lsnr1 Node 2 Network Client 1 Client 2 Client 3 Client n

30. page 30 Listener Load Balancing Listeners balance load using CPU/user load Node 1 rac2 instance lsnr2 9iRAC Database rac1 instance lsnr1 Node 2 Network Client 1 Client 2 Client 3 Client n

31. page 31 Connect Time Failover Automatically retries the connection (uses the next entry in the address list in tnsnames.ora) Client TNS Node 1 rac2 instance lsnr2 9iRAC Database rac1 instance lsnr1 Node 2

32. page 32 TAF, Overview Oracle9i provides a high availability architecture that provides transparent client failover capability – Little or no user downtime – Applications and users are automatically and transparently reconnected to another system – Applications and queries continue uninterrupted – Login context maintained ComputerAComputerBComputerAComputerB Node A in an RAC cluster fails, users are migrated

33. page 33 Characteristics of TAF TAF protects or fails-over: Client/server connection User session state Active cursors (select statements) that have begun to return results Not failed over: - Active update transactions - PL/SQL server-side package variables

34. page 34 Three “ Levels ” of TAF Functionality TYPE=SESSION, METHOD=BASIC (Login Failover) Client is automatically logged into surviving node of cluster TYPE=SELECT (Statement Failover) Node failure occurs during query Client fails over to a surviving node and is logged in Query replayed on surviving node but only rows not returned during the original query execution are returned METHOD=PRECONNECT (“Fast” Session Failover) Client connected to two instances at session establishment Avoid impact of “login storm” during failover to surviving node in Real Applications Cluster or Oracle Parallel Server

35. page 35 TAF Select Failover Failover allows the application to continue execution or fetching Leverages Oracle’s multi-versioning read consistency to ensure results are identical SELECT * FROM emp; Instance 2 Client empno name 7369 Smith 7499 Allen 7521 Ward 7566 Jones 7654 Martin 7698 Blake Instance 1 DB empno name 7369 Smith 7499 Allen 7521 Ward 7566 Jones 7654 Martin 7698 Blake Rows Partially Returned When Failover Occurred Continues Returning Remaining Rows from here