Oracle 10g RAC Overview.ppt

1、Oracle RAC,Overview of Real Application Clustering Features and Functionality,Overview,What is RAC? Cache Fusion Failover and Load-balancing Transparent Application Failover (TAF) Other RAC Features,RAC What is it?,Multiple instances of Oracle running on up to 8 nodes Multiple instances share a sing

2、le physical database All instances can simultaneously execute transactions against the single database Caches are synchronized using Oracles Global Cache Management technology (Cache Fusion),Previous Oracle Clustering Products Oracle FailSafe on Windows OPS (Oracle Parallel Server) on multiple platf

3、orms OPS to RAC: 7.3 OPS 8i OPS 9i RAC 10g RAC The clustering mechanism used to be more dependent on the Operating System. With 10g RAC, clustered database is built into Oracle,History of Oracle RAC,Oracle RAC Features,Full Cache Fusion Enhanced coordination of cache management and distributed lock

4、manager (DLM) Lock simplification and automation Global Cache Service coordinates local buffer cache and remote block transfers Enhanced IPC Resource configuration simplification and automation Improved cluster aware tools Enhanced DBCA Oracle Enterprise Manager and Grid Control Integration Enhancem

5、ents,RAC uses “Shared Everything”,Users,Database,How RAC clustering is done,One set of data All nodes in the cluster see the same set of data All nodes have access Any node can update the data,Increased Manageability,One virtual system to configure and manage Single Oracle Database Single management

6、 console Single system image for the database integrated with the cluster Cluster-wide monitoring and diagnostics Oracle Enterprise Manager Integration (9i) Oracle DBConsole and Grid Control Integration (10g),Whats shared; Whats not,Shared Disk access Resources that manage data All instances have co

7、mmon data they dont need to log back into the system Applications and users are transparently reconnected to another node Applications and queries continue uninterrupted Transactions can failover and replay Login context maintained DML transactions are rolled back,RAC Improvements for Oracle 9i,Full

8、 Cache Fusion Enhanced coordination of cache management and distributed lock manager (DLM) Lock simplification and automation Global Cache Service coordinates local buffer cache and remote block transfers Enhanced IPC (InterProcess Communication) Resource configuration simplification and automation,

9、Oracle 10g RAC New Features,Integrated Clusterware Management No third-party clusterware software required Automatic Workload Management Application workloads can be managed through named services Single System Image Management Enterprise Manager manages RAC instances as a single image Fast Connecti

10、on Failover Fast recovery between the database and mid-tier applications Performance Improvements Reduced message traffic, memory usage, and other resources Zero Downtime Patching Patches may be applied one node at a time without downtime Cluster Verification and Improved Diagnostic Tools New cluste

11、r diagnostic tool and improved diagnostic tools,Full Cache Fusion,Is a major feature of RAC starting with 9i The underlying technology that enables RAC Protocol that allows instances to combine their data caches into a shared global cache Allows any node to get the most up-to-date data information f

12、rom the cache of any other node in the cluster without having to access the disk drives again. Improved performance with 10g,What is Cache Fusion? When do I care about it?,“Dirty” block of data is created Data from disk is read into memory on a node Data is updated on that node Data hasnt been writt

13、en to disk yet. Another node requests the data,“ABC” block of data written to the disk drives in the database,Node A,Node B,ABC Data,“ABC” block of data read into memory on Node A,Node A,Node B,ABC Data,ABC Data,“ABC” updated to “XYZ” in cache,Node A,Node B,ABC Data,ABC Data,XYZ Data,Node B requests

14、 data block,Node A,Node B,ABC Data,ABC Data,XYZ Data,I want data! Gimme! Gimme!,Node A must write data block to disk drive,Node A,Node B,ABC Data,XYZ Data,I want data! Gimme! Gimme!,ABC Data,XYZ Data,write,Previous to 9i RAC,Node B must read data block from disk drive,Node A,Node B,ABC Data,XYZ Data

15、,XYZ Data,ABC Data,XYZ Data,read,Previous to 9i RAC,Now with RAC Cache Fusion,Node A,Node B,ABC Data,ABC Data,XYZ Data,I want data! Gimme! Gimme!,XYZ Data,Data is transferred immediately via the interconnect Shared cache minimizesslow I/O,Shared Cache Across Nodes,Users,Database,Resource Simplificat

16、ion and Automation,No init.ora parameters required Resource affinity to move the location of the resource masters for a database file to the instance where block operations are most frequently occurring. This optimizes Dynamic resource remastering Ability to move the ownership of a resource between instances of Real Application Clusters. Dynamic resource remastering is used to implement resource affinity for increased performance.,Review,What does cache fusion avoid that was mandatory in previous versions of Oracle Parallel Server? Which