* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Achieve Continuous Database Availability with Active
Survey
Document related concepts
Serializability wikipedia , lookup
Tandem Computers wikipedia , lookup
Extensible Storage Engine wikipedia , lookup
Open Database Connectivity wikipedia , lookup
Navitaire Inc v Easyjet Airline Co. and BulletProof Technologies, Inc. wikipedia , lookup
Relational model wikipedia , lookup
Microsoft Jet Database Engine wikipedia , lookup
Functional Database Model wikipedia , lookup
Concurrency control wikipedia , lookup
Oracle Database wikipedia , lookup
Database model wikipedia , lookup
Transcript
Achieve Continuous Database Availability with Active-Active Replication Sujith Kumar, Chief Technologist Dell Software Syamal Bandyopadhyay, Database Solution Architect Verizon Wireless Agenda • Introduction to a five nines system • Different mechanisms of achieving high availability • Consider database replication • Customer Example – Verizon Wireless • Q&A 2 Software Introduction to highly available systems 3 Software Introduction to a highly available system • What is five nines in terms of high availability? – Percentage of system uptime in a given year – *Allowable unscheduled downtime in a given year 4 Availability % Downtime per year* Downtime per month Downtime per week 90% ("one nine") 36.5 days 72 hours 16.8 hours 95% 18.25 days 36 hours 8.4 hours 97% 10.96 days 21.6 hours 5.04 hours 98% 7.30 days 14.4 hours 3.36 hours 99% ("two nines") 3.65 days 7.20 hours 1.68 hours 99.5% 99.8% 1.83 days 17.52 hours 3.60 hours 86.23 minutes 50.4 minutes 20.16 minutes 99.9% ("three nines") 8.76 hours 43.8 minutes 10.1 minutes 99.95% 99.99% ("four nines") 99.999% ("five nines") 99.9999% ("six nines") 4.38 hours 52.56 minutes 5.26 minutes 31.5 seconds 21.56 minutes 4.32 minutes 25.9 seconds 2.59 seconds 5.04 minutes 1.01 minutes 6.05 seconds 0.605 seconds 99.99999% ("seven nines") 3.15 seconds 0.259 seconds 0.0605 seconds Software Introduction to a highly available system • Availability and uptime are not synonymous. – Network outage • A five nines or higher system is designed to eliminate a single-pointof-failure – Maintenance activities: hardware, network, operating system, middleware, patches & upgrades • Why five nines and not six nines or seven nines? – Higher Service Level Agreements(SLA) are rare – Exorbitantly expensive to implement – Typically does not include scheduled downtime 5 Software Anatomy of a highly available system Internet & Intranet Data Center Load Balancers Application/Web Servers Database Servers Oracle Data Guard Dell SharePlex Oracle RAC Storage Replication Storage SAN/NAS Disk Mirroring 6 Oracle RAC Disk Mirroring Software Challenges in achieving a highly available system • Application availability depends on all components in the stack – – – – – Data Centers Load Balancers, Routers, Switches (Network) Middle-Tier (Application & Web Servers) Database Servers (OS Clustering, Database Clusters – Oracle RAC) Storage (SAN/NAS Block Level Replication) • Database is the single-point-of-failure by not being able to provide an always “hot” database for the middle-tier servers to connect to. – Solution: Maintain a secondary “hot” database for instant fail-over/fail-back – Provide instantaneous fail-over—Implement database level load-balancing – Key: Dell SharePlex 7 Software Consider Database Replication (Dell SharePlex) 8 Software SharePlex is #1 third party database replication solution SharePlex is a “High Availability Solution” for Oracle databases that is affordable, simple to use & easy to manage. - Leading database replication software since 1998 - Gartner 2010 recommends SharePlex to reduce costs with Oracle Standard Edition Worldwide Database Replication Market Share 2011 Oracle 25.5% Other 29% - IDC 2011 SharePlex is #1 third party solution IBM 11% SAP 15% Quest Software 19% Source: Worldwide Database Development and Management Tools 2011 Vendor and Segment Analysis, IDC #237963 November 2012 9 Software What is SharePlex & How does it work? Target SharePlex is a logical data replication solution • Real-time copy of data without impacting database performance and availability Source • Analogous to receiving e-mails seamlessly in Outlook and mobile devices simultaneously • Data is replicated from one or more source database(s) to one more target database at the same time • Runs continuously, replicating data from source to target in real-time with subsecond latency 10 Replicate from source to target with very few limitations Software SharePlex Oracle-to-Oracle architecture On-premises, remote, or in-the-Cloud Export Export queue Import Post queue SQL Redo/Archive logs Post Read Post Capture Source 11 Capture queue Cloud target Target Software Why consider SharePlex? OS/Hardware Clustering Requires same type and version of the operating system In most cases requires similar hardware Requires specialized and proprietary clustering software Does not provide cross datacenter redundancy Expensive option due to identical redundant hardware Due to active-passive configuration, only a single node within the cluster is active at all times. 12 Oracle RAC One physical database, multiple servers/instances. − What if the database is down? Allows for workload distribution, but does not optimize for different types of workloads All nodes in the same data center over local/private network connections. Extended distance clusters are limited to 100 KMS or less Does not provide user load balancing across multiple databases Requires Dataguard for datacenter redundancy Storage Technologies Requires proprietary block level replication software High network bandwidth utilization – replicates everything Most solutions require like hardware on both ends Allows for only one copy of the data to be hot at any time Redundant copies of the same data not being used Expensive hardware required for datacenter redundancy SharePlex Extends to multiple databases, no outage Multiple copies of the databases - can be customized for different workloads Allows for true database load-balancing just like network load-balancers Minimal network bandwidth utilization Minimal load on the database Transparent to hardware, operating system, storage & applications Provides flexible datacenter redundancy Software Why consider SharePlex? SharePlex Features Low overhead on source database (1-3%) Near real-time replication—target database(s) remains live and accessible Customizable replication—entire database, selective schemas, tables, columns, and/or rows Allows in-flight data transformation if required Supports mixed environments with differing source/target OS, database editions, and database versions Oracle Enterprise Edition, Oracle Standard Edition, Oracle ASM, Oracle RAC, 9i-12c, Microsoft Windows, Unix, Linux, Oracle Exadata, operating system clustered environments Monitoring, automated conflict detection and resolution (predefined and user defined) Automated data integrity check and repair (SharePlex Compare and Repair) Change data capture—change tracking, data integration All the functionality included in the product—no additional modules needed 13 Software SharePlex: Peer-to-Peer Replication Architecture SharePlex peer-to-peer replication architecture Export queue SharePlex replication Post queue Capture queue Upgrades: Database Operating System Storage Application Secondary production Capture queue SharePlex reverse replication Primary production 15 Post queue Export queue Software SharePlex active-to-active considerations • Well suited for home-grown application versus off-the shelf applications, such as, SAP, PeopleSoft etc. • Business considerations – Transaction impact – example: inventory management, user profile etc. – Batch operations (jobs) • Database considerations – – – – Sequences Triggers Conflict Resolution Conflict Validation • Conflict Avoidance – Geographic isolation, application re-design, adding date/time columns to database tables 16 Software Case Study Verizon Wireless VZW – Continuous Availability Deployment Architecture Why Verizon Wireless chose SharePlex ? Logical Data Replication with SharePlex Oracle Physical Data Guard Description Support Active-Active Configuration No Yes Source/Target having additional database objects Ok - for some scenarios (generally not recommended) Yes Read/Write Access for all source and target sites (concurrently both source and target) Not Supported Supports Peer-to-Peer Concurrent Replication (e.g 3 way) No Yes Support one source, multiple target sites Yes Yes Ease of Failover Yes (using command or Data Guard Broker) Yes Limitations/ Constraints Unless select appropriate 'mode', may cause production latency Latency on target increases with very high transaction volume True Disaster Recovery (DR) only Excellent Excellent Failover & Failback Easy Always ready to use 19 Software Why Verizon Wireless chose SharePlex ? Logical Data Replication with SharePlex Oracle Physical Dataguard Description Product Stability Very Stable Very Stable Tuning opportunities Yes Yes Support for Very High Volume insert/update/delete Transactions requiring replication Yes Yes (Requires tuning) Handling Foreign Key Constraints No customization required Special consideration required Data Synch time on target site (based on VZW Observations) Depends on configuration (max. availability, max. performance) Typically less than 2 seconds Intentional Delay in applying source changes to targets Yes, can be configured Yes, can be configured Data Resynchronization Between Source and Target May require full database refresh or copy Can be synchronized using compare/repair or copy process 20 Software Summary 21 Software Summary • SharePlex is a high-availability solution for databases 22 Ability to maintain multiple active copies of the database Provides instantaneous database failover and failback Support for conflict resolution using built-in or custom resolutions Performance tuning Flexibility for geographic needs Supports disparate platforms and versions Ability to upgrade with no downtime Software Questions 23 Software Next Steps For more information, visit the SharePlex webpage URL Link: www.software.dell.com/SharePlex • Datasheet, Videos, Case studies, White Papers, Technical Briefs, Events/Webcasts Ask a Dell Software Account Manager for a Proof of Concept (POC) • • • Download 30-day Trial Software (SC and Support Assistance) On your own test environment Dell Cloud Sandbox Join our SharePlex Community: URL Link: www.Quest.com/Community-SharePlex • 24 Discussions, Blogs, Expert Advice, Polls, Demo’s, technical documents, etc. To learn more about TM SharePlex Visit software.dell.com/SharePlex 25 26