Professional RAC (Real Application Clusters) Interview Questions & Answers:

1. Do you know what are the tools provided in Oracle Enterprise Manager?

- Oracle Enterprise Manager provides a Grid Control that is used to deliver the centralized management system and provides configuration and administration capabilities.

- It provides the cost reduction plans and provides higher efficiency that allows the time to be saved for other server control actions.

- Oracle Enterprise Manager Database Control that is used as a graphical management tool to manage the database to make it configure automatically.

- It is related to the Oracle Clusterware and is used to manage the services of the Oracle RAC.

- It also manages the server pools that are being created with the Oracle Clusterware and provision to manage it from a single place.

2. Do you know what is the purpose of SCAN?

- SCAN stands for Single Client Access Name which is an integral part of the Oracle RAC.

- It simplifies the client access that is used with the Oracle RAC databases and provides an easy way to access all other resources by using the single name.

- Only a single name allows the accessing to be done of all the resources that is being taken up by the clusters on the servers.

- SCAN is used to manage the connection request that is coming from the client and that doesn't change when the cluster is scaled and when the nodes changes in the cluster.

- It uses a simplified connection string called as EZConnect to connect to various databases and systems.

3. Tell me what are the components required to manage Oracle Real Application Clusters Database?

- Oracle RAC uses a single system in the form of an image to configure and manage the servers in an easy way.

- It provides a database for the installed and configured applications from one location so that it can be managed in an easy way.

- The components required to be provided with it is as follows:
- Oracle Universal Installer (OUI) is used to manage the database that is related to the cluster and provide enterprise level configuration.
- Database configuration assistant (DBCA) that manages the database and its related functionality and services.
- Database upgrade assistant (DBUA) is the tool that allows the database to be upgraded when it is required on the server.

4. Can you explain what are the benefits of Oracle Real Application Clusters (RAC)?

- Oracle RAC provides High availability that becomes the foundation of the high end components used in Oracle's Maximum Availability Architecture.

- Oracle RAC also provides Reliability for the Oracle Database that is being used in a widespread and allows user to easily remove the database server from a single point of failure.

- Oracle RAC focuses on Recoverability that if any failure occurs then the database should be such that it can recover from the failures. For example, connection failure.

- Oracle RAC provides an Error Detection mechanism that allows Oracle Clusterware to automatically monitors, detects and fix the error if any.

- Oracle RAC provides Scalability that is more useful in long term applications where the server runs out of the capacity and the cost is also low then it provides an easy way to increase the servers and pools to fit all the components.

5. Tell me why is Cluster Verification Utility so important in Oracle RAC?

- Cluster Verification Utility is a tool in the Oracle Grid that is used to eliminate the errors that come up with the validations of the steps.

- It provides the verification on the changes that is being made in the configuration of the files or the system.

- The tool can be used with the command line interface and it is used to validate the configuration input as well such that during the installation it can be found out that everything is perfectly ok.

- The tool is used to verify the system pre-requisites that are related to Oracle Clusterware, ASM and the databases.

- There are few fix up scripts available if by any means the verification tool fails then these scripts can be used to automatically fix the errors.

6. Do you know the Load Balancing Advisory?

- Load balancing advisory is a process through which the load of the applications and resources can be managed throughout the servers.

- It monitors the workload of the current activities from all the clusters and the instances that is being given on the server.

- The service that is being provided is active all the time to see the workload of the applications on the servers.

- To simplify it, it provides a percentage value to show the total workload of the instance and it flags the instance according to the quality.

- Load Balancing Advisory helps in maintaining the loads from the servers and equally distributes it among many other servers that are not currently working.

7. Do you know Oracle Grid Infrastructure?

- Oracle Grid Infrastructure provides the support for Oracle Automatic Storage Management that has the solution for the database that is being used.

- Oracle Grid Infrastructure provides the solutions and software bundles to make it universal for its distribution.

- It provides a way to have the volume management, file system management and server pool management that is directly related to the Oracle RAC database.

- Oracle Grid Infrastructure provides complexity and can only be monitored and handled by the system administrator.

- Oracle Grid Infrastructure handles the grid functionality and provision to integrate the applications and services in the infrastructure.

8. Please tell me what is the function of Grid Naming service used in Oracle RAC?

- Oracle RAC provides this Naming service that provides easiness in scaling up the automation of the VIP management system of the Oracle RAC architecture.

- GNS (Grid Naming Service) has to be maintained and monitored by the Network Administrator to maintain the DNS of the system.

- Virtual IP addresses can be maintained by using the cluster and automation can be made in regards of assigning of the IPs.

- Adding of the servers can take place from the pool when the network administrator returns additional IP addresses and GNS requires DHCP server through which it can be accessed publicly.

- The DHCP service of the Oracle allows the dynamic allocation of the Virtual IP addresses that allows the cluster to be joined together in a server.

- GNS provides automation to the system and removes the entire manual configuration with the dynamic nature of the system.

9. Explain what is the function of having Virtual Internet Protocol Address (VIP) in Oracle RAC?

- Oracle RAC is using the virtual IP address for each server that is present in the cluster as it allows easy management of the Oracle Clusterware by taking the subnet as LAN.

- The VIP address is used by the applications and services of the Oracle RAC and then it also helps in connecting it to the Oracle RAC database.

- Virtaul IP addresses keep track of the failures and if one node fails then the load gets shifted to another node that is present in the cluster.

- This provides an easy way to manage the node down response for the incoming connections and provide the requests for that connection.

- It helps in increasing the availability for the services and the applications that takes longer time to run before the request fails.

- It changes the server pool addresses if the connection fails in between while serving any request from any other source.

10. Do you know what are the file systems and volume management techniques used in Oracle RAC?

- The file system and volume management in Oracle RAC should know about the architecture that is being used and it should be aware of the clusters that are involved in it.

- Oracle supports automatic storage management that automates the storing of files and setup the communication in between the databases storage pools.

- Oracle supports the high performance of the input and output of the storage subsystem by providing easy tools to use to maximize it.

- They provide a way to balance the load across the available resources that allows the correct optimization of the file system and volume management.

- Oracle RAC provides dynamic volume manager and it has a file system that contains the information of the cluster file system as well.

- The cluster file system in oracle is called as (OCFS) and it has the connection with the databases that provide raw devices and command line features.