Ans: Oracle RAC architecture is an engineered system that provides high availability, scalability, and performance for database workloads. It is designed to give users the option to scale their system up or down as needed, without incurring downtime. Oracle RAC also provides a number of features that make it easier to manage large-scale deployments.
Ans: Oracle RAC architecture is a clustered database system that provides high availability, scalability, and load balancing. The system consists of a group of database servers that are interconnected via a network and share a common database. Each database server includes a copy of the database, and the system automatically failover to another database server if one database server fails.
Which of the following is RAC architecture?
Oracle Real Application Clusters (RAC) is an option for the Oracle Database that allows multiple instances to access a single database. RAC is available on all major platforms, including Linux, UNIX, and Windows. RAC provides high availability and scalability for the Oracle Database.
Oracle RAC has two modes of operation: Fail-Over and Workload balance. Only one node processes client requests. For high availability, the second node (called the failover node) is ready in a standby mode, and is activated when the first node fails.
What are Oracle RAC components
Oracle RAC is a clustered database system that consists of three components: The Oracle clusterware software (CRS), software to create and manage the communication between the cluster of nodes, and the relational database (RDBMS). The Oracle RAC system provides high availability and scalability by allowing multiple instances of the Oracle database to run on a cluster of servers.
Oracle Real Application Clusters (RAC) is an option for the Oracle Database that allows customers to run a single Oracle Database across multiple servers. RAC provides high availability and horizontal scalability while accessing shared storage.
What is RAC and how it works?
RAC or Reservation Against Cancellation is a type of ticket that allows two passengers to share the same berth. If a confirmed passenger does not board the train, the passenger with RAC ticket is allotted a full berth.
Oracle RAC is a clustering technology that allows multiple computers to run Oracle RDBMS software simultaneously while accessing a single database. This provides high availability and scalability for the Oracle database. In a non-RAC Oracle database, a single instance accesses a single database. The database consists of a collection of data files, control files, and redo logs located on disk.
Does Oracle RAC require ASM?
If you want to set up a RAC (Real Application Clusters) cluster, you must use Oracle Clusterware to manage the nodes. Part of the clusterware is ASM (Automated Storage Management), but it is not mandatory that you use ASM. If you choose not to use ASM, then the shared file system architecture you use must be certified by Oracle as being okay for RAC.
Oracle recommends that the SCAN resolves to three VIP addresses, to provide high availability and scalability. If the SCAN resolves to three addresses, then three SCAN VIPs and three SCAN listeners are created. Each SCAN listener depends on its corresponding SCAN VIP.
Why does Oracle RAC have 3 scan listeners
SCAN listeners are used to provide high availability and load balancing for cluster nodes. Each cluster should have a minimum of 1 and a maximum of 3 SCAN listeners.
Load balancing is a technique used to distribute workloads across multiple computing resources, such as servers, disks or networks. The goal of load balancing is to optimize resource use, minimize response time and avoid overloading any single resource.
What is the difference between Oracle RAC and Grid?
RAC is a type of cluster computing in which each node in the cluster is connected to a central server. The server manages the resources of the cluster and allocates them to the nodes as needed. Nodes in a RAC cluster cooperatively work together as a single unified resource.
Grid computing is a type of computing in which resources are shared on demand within a tightly-coupled network. Grid computing is often used for high-performance computing applications which require a large amount of computing power.
The Oracle RAC background processes are responsible for managing resources and maintaining communication across the cluster. The LMON process monitors global enqueues and resources, and performs global enqueue recovery operations. The LMD process manages incoming remote resource requests within each instance.
How many nodes are there in Oracle RAC
A RAC database instance is a set of processes and memory that operates on the database files. A RAC database instance resides on one node.
In a single-instance database, there is a one-to-one relationship between the instance and the database. An instance can access one and only one database. With Oracle RAC, there are multiple instances for one database. Each instance runs on a separate database server, called a node in the cluster.
An Oracle RAC database is a shared everything database. All data files, control files, SPFILEs, and redo log files in Oracle RAC environments must reside on cluster-aware shared disks, so that all of the cluster database instances can access these storage components.
If you have a RAC status ticket, it means that you are guaranteed a seat on the train, but not a berth for sleeping. So if you are a passenger with a RAC status, it means that you can enter the train and occupy your seat on the train. When RAC status is filled out then you are assigned a waitlist status number.
Warp Up
Oracle RAC is a scalable, highly available database solution that provides high performance and protection from planned and unplanned outages. RAC databases are deployed on a cluster of independent servers that work together to provide a single, logical database. If one server in the cluster fails, the others can continue to process transactions, providing continuous availability. RAC databases can be deployed on commodity hardware, making them a cost-effective solution for businesses of all sizes.
Oracle Real Application Clusters (RAC) is a clustered version of the Oracle Database that can provide significant scalability, performance, and availability benefits for any application. RAC databases are easy to manage and provide users with a single point of contact to the database, regardless of which server in the cluster is currently serving their requests. RAC is an ideal solution for any organization that needs to scale its Oracle database to meet growing demands.
