OVERVIEW OF ORACLE RAC
A cluster consists of multiple interconnected computers or servers that appear as if they are one server to end-users and applications. Oracle RAC permits you to cluster an Oracle database. Oracle RAC uses Oracle Clusterware for the infrastructure to bind multiple servers so they function as a single system.
Oracle Clusterware is a portable cluster management solution that is built-in with Oracle Database. Oracle Clusterware is also a required component for using Oracle RAC. In addition, Oracle Clusterware allows both non-cluster Oracle databases and Oracle RAC databases to use the Oracle high-availability infrastructure. Oracle Clusterware enables you to create a clustered pool of storage to be used by any combination of non-cluster and Oracle RAC databases. Oracle Clusterware is the only Clusterware that you want for most platforms on which Oracle RAC operates. You can additionally use Clusterware from other providers if the Clusterware is certified for Oracle RAC.
Non cluster Oracle databases have a one-to-one relationship between the Oracle database and the instance. Oracle RAC environments, however, have a one-to-many relationship between the database and instances. An Oracle RAC database can have up to 100 instances, all of which access one database. All database instances need to use the identical interconnect, which can additionally be used by Oracle Clusterware. Oracle RAC databases vary architecturally from non-cluster Oracle databases in that each Oracle RAC database instance also has:
- At least one additional thread of redo for each instance
- An instance-specific undo tablespace
- The combined processing power of the multiple servers can provide greater throughput and Oracle RAC scalability than is accessible from a single server.
The key characteristics of RAC are:
Reliability: Eliminates the database server from a single factor of failure. If an instance fails, the remaining instances in the cluster remain active and open.
Error Detection: Provides quick detection of issues in the environment. It automatically recovers from failures even before users notice that a failure has occurred.
Recoverability: Easy to get better from various types of failures.
Continuous Operations: provides continuous service for both unplanned and planned outages
The Main Purpose of Oracle Real Application Clusters (RAC)
Oracle Real Application (RAC) gives the interaction of executable files with the Oracle database. It permits the running of any packaged or custom-built application with Oracle DB that is running on a server pool. It gives a very high level of availability, flexibility, and scalability to run the application and store it in the database. It creates the database such that if the pool fails then the database is endured to run from the remaining servers and the load can be distributed. It makes it easier for the administrator to maintain many servers at the same time via load-balancing methods and providing provision to add more and more servers when the load increases.
LATEST FEATURES AND FUTURE OPPORTUNITIES
Oracle has constantly enhanced Oracle RAC technology, making it easier, faster, more scalable, and more available culminating in the breakthrough Oracle RAC 19c release that permits RAC to meet the needs of all next-generation workloads and applications. Oracle RAC has improved its performance for high competition workloads by 5 times given that Oracle RAC 11g Release 2 while the brownout time all through clustered configuration and after an instance failure has been reduced by four times between Oracle RAC 11g Release 2 and Oracle RAC 12c Release two and by yet another 1.5 times between Oracle RAC 12c Release 2 and Oracle RAC 19c. This means that an application that skilled a brownout time of one minute with Oracle RAC 11g Release 2 may find itself totally operational after a failure in less than 15 seconds with Oracle RAC 19c.
Oracle RAC online training at Gologica enables you to obtain proficiency in Oracle RAC (Real Application Cluster) database architecture. There are loads of opportunities from many reputed organizations in the world. According to research, Oracle RAC has a market share of about 1.0%. The main aim of the Oracle RAC online course is to enforce a clustered database to provide performance, scalability, and resilience. The training will assist you to learn about Oracle Database Exadata Cloud Service and the fundamentals of Database Administration. You will master the RAC software and learn how to create cluster databases, administer Oracle RAC databases, control and screen issues, and create and monitor the RAC One Node database. As part of this training, you will be working on real-time projects and assignments that have huge implications in the real-world industry scenarios, hence helping you fast-track your career effortlessly.
