DB2 pureScale Overview Sept 2010
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DB2 pureScale provides a highly scalable and available database solution. It allows customers to start small and grow capacity easily by adding additional cluster members without disrupting applications or incurring extra costs. DB2 pureScale uses a shared nothing architecture with each member running on its own server. It provides a single system view to clients and automatically balances workload across members. Critical features include unlimited scalability, continuous availability even during member failures, and the ability to perform maintenance without outages.
DB2 pureScale Overview Sept 2010
- 1. © 2010 IBM CorporationSeptember 29, 2010 DB2 pureScale Value Proposition and Technology Overview Matt Huras, IBM huras@ca.ibm.com
- 2. Information Management © 2009 IBM Corporation2 Agenda Why DB2 pureScale ? Technology Overview Key Design Points Scalability Availability
- 3. Information Management © 2009 IBM Corporation3 Customers need a highly scalable, flexible solution for the growth of their information with the ability to easily grow existing applications Critical IT Applications Need Reliability and Scalability Down-time is Not Acceptable – Any outage means lost revenue and permanent customer loss – Today’s distributed systems need reliability Local Databases are Becoming Global – Successful global businesses must deal with exploding data and server needs – Competitive IT organizations need to handle rapid change
- 4. Information Management © 2009 IBM Corporation4 IT Needs to Adapt in Hours…Not Months Application Changes are Expensive – Changes to handle more workload volume can be costly and risky – Developers rarely design with scaling in mind – Adding capacity should be stress free Handling Change is a Competitive Advantage Dynamic Capacity is not the Exception – Over-provisioning to handle critical business spikes is inefficient – IT must respond to changing capacity demand in days, not months Businesses need to be able grow their infrastructure without adding risk
- 5. Information Management © 2009 IBM Corporation5 Introducing DB2 pureScale Learning from the undisputed Gold Standard... System z Unlimited Capacity – Buy only what you need, add capacity as your needs grow Application Transparency – Avoid the risk and cost of application changes Continuous Availability – Deliver uninterrupted access to your data with consistent performance
- 6. Information Management © 2009 IBM Corporation6 DB2 pureScale Architecture from 10,000 ft. Leverages the global lock & buffer manager derived technology from z/OS Automatic workload balancing Shared Data InfiniBand network & DB2 Cluster Services Cluster of DB2 nodes Integrated Failure Detection & Recovery Automation
- 7. Information Management © 2009 IBM Corporation7 Need more… just deploy another server and then turn off DB2 when you’re done. Issue: All year, except for two days, the system requires 3 servers of capacity. Solution: Use DB2 pureScale and add another server for those two days, and only pay sw license fees for the days you use it. Virtually Unlimited Capacity DB2 pureScale supports up to 128 members in initial release Flexible licensing designed for minimizing costs of peak times Only pay for additional capacity when you use it even if for only a single day
- 8. Information Management © 2009 IBM Corporation8 Without Daily Licensing 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% J F M A M J J A S O N D Workload CPU Demand Licensing Need
- 9. Information Management © 2009 IBM Corporation9 With DB2 pureScale Daily Licensing 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% J F M A M J J A S O N D Workload CPU Demand Licensing Need Savings License Cost Savings
- 10. Information Management © 2009 IBM Corporation10 Continuous Availability Protect from infrastructure outages – Architected for no single point of failure Automatic workload balancing Automatically recovers from component failures Tolerates multiple node failures Duplexed secondary global lock and buffer manager
- 11. Information Management © 2009 IBM Corporation11 Cluster Interconnect Technology Overview Single Database View Clients Database Log Log Log Log Shared Storage Access CS CS CSCS CS CS CS Member Member Member Member Primary2nd -ary DB2 engine runs on several host computers – Co-operate with each other to provide coherent access to the database from any member Data sharing architecture – Shared access to database – Members write to their own logs – Logs accessible from another host (used during recovery) Cluster caching facility (CF) from IBM STG – Efficient global locking and buffer management – Synchronous duplexing to secondary ensures availability Low latency, high speed interconnect – Special optimizations provide significant advantages on RDMA-capable interconnects (eg. Infiniband) Clients connect anywhere,… … see single database – Clients connect into any member – Automatic load balancing and client reroute may change underlying physical member to which client is connected Integrated cluster services – Failure detection, recovery automation, cluster file system – In partnership with STG (GPFS,RSCT) and Tivoli (SA MP) Leverages IBM’s System z Sysplex Experience and Know-How
- 12. Information Management © 2009 IBM Corporation12 Scalability : Example Transaction processing workload modeling warehouse & ordering process – Write transactions rate to 20% – Typical read/write ratio of many OLTP workloads No cluster awareness in the application – No affinity – No partitioning – No routing of transactions to members – Testing key DB2 pureScale design point Configuration – 12 8-core p550 members • 64 GB, 5 GHz each – Duplexed PowerHA pureScale across 2 additional 8-core p550s • 64 GB, 5 GHz each – DS8300 storage • 576 15K disks, Two 4Gb FC Switches – IBM 20Gb/s IB HCAs • 7874-024 IB Switch 1Gb Ethernet Client Connectivity 20Gb IB pureScale Interconnect 7874-024 Switch Two 4Gb FC Switches DS8300 Storage p550 members p550 powerHA pureScale Clients (2-way x345)
- 13. Information Management © 2009 IBM Corporation13 Scalability : Example 0 1 2 3 4 5 6 7 8 9 10 11 12 0 5 10 15 1.98x @ 2 members 3.9x @ 4 members # Members Throughputvs1member 7.6x @ 8 members 10.4x @ 12 members
- 14. Information Management © 2009 IBM Corporation14 Run-time load information used to automatically balance load across the cluster – Shares design with system z Sysplex – Load information of all members kept on each member – Piggy-backed to clients regularly – Used to route next connection (or optionally next transaction) to least loaded member – Routing occurs automatically (transparent to application) Failover – Load of failed member evenly distributed to surviving members automatically Fallback – Once the failed member is back online, fallback does the reverse ClientsClients Workload Balancing
- 15. Information Management © 2009 IBM Corporation15 Automatic, Online, Member Recovery Log CS CS DB2 Shared Data Clients Power cord tripped over accidentally DB2 Cluster Services looses heartbeat and declares member down – Informs other members & CF servers – Fences member from logs and data – Initiates automated member restart on another (“guest”) host > Using reduced, and pre-allocated memory model – Member restart is like a database crash recovery in a single system database, but is much faster • Redo limited to inflight transactions (due to FAC) • Benefits from page cache in CF In the mean-time, client connections are automatically re-routed to healthy members – Based on least load (by default), or, – Pre-designated failover member Other members remain fully available throughout – “Online Failover” – Primary retains update locks held by member at the time of failure – Other members can continue to read and update data not locked for write access by failed member Member restart completes – Retained locks released and all data fully available CS DB2 CS DB2 CS Updated Pages Global Locks LogLogLog PrimarySecondary Updated Pages Global Locks Fence CS DB2 DB2 Pages Log R ecs Single Database View Automatic; Ultra Fast; Online Database remains available throughout. Affected connections transparently re-routed to other members.
- 16. Information Management © 2009 IBM Corporation16 Automatic, Online, Member Failback Log CS CS DB2 Shared Data Clients Power restored and system re- booted DB2 Cluster Services automatically detects system availability – Informs other members and PowerHA pureScale servers – Removes fence – Brings up member on home host Client connections automatically re- routed back to member CS DB2 CS CS Updated Pages Global Locks LogLogLog PrimarySecondary Updated Pages Global Locks CS DB2 DB2 Single Database View DB2
- 17. Log LogLogLog Goal: allow DBAs to apply system maintenance without negotiating an outage window Procedure: Drain (aka Quiesce) Remove & Maintain Re-integrate Repeat until done Single Database View DB2 DB2 DB2 DB2 Stealth System Maintenance
- 18. Information Management © 2009 IBM Corporation18 pureScale is a Complete Solution Single Database View Clients Database Log Log Log Log Shared Storage Access Cluster Interconnect Member CS Member CS Member CS CS CS Member CSCS DB2 pureScale is a complete software solution – Comprised of tightly integrated subcomponents Single install invocation – Installs all components across desired hosts – Automatically configures each No cluster manager scripting or configuration required – This is set up automatically, upon installation
- 19. Information Management © 2009 IBM Corporation19 Questions ?