In response, Oracle gives the client a connection to an active instance thatĪns: Transparent Application Failover (TAF) - A runtime failover for high If you configure the client to use fast connection failover, then the clientĪutomatically subscribes to FAN events and can react to database UP and DOWN events. Such as clients that use JDBC, OCI, or ODP.NET. The FAN process uses system events that Oracle publishes when cluster serversīecome unreachable or if network interfaces fail.Īns: Fast Connection Failover provides high availability to FAN integrated clients, As a result, you don't really have a good HA solution without using VIPs.Ģ4) How many Scan Listeners will be running?Īns: Applications can use Fast Application Notification (FAN) to enable rapidįailure detection, balancing of connection pools after failures, and re-balancing of connection pools when failed components are repaired. Wait for a TCP timeout period (which can be up to 10 min) before getting anĮrror. Without using VIPs or FAN, clients connected to a node that died will often RST packets back to the clients.This results in the clients getting errors immediately. Subsequent packets sent to the VIP go to the new node, which will send error
ORACLE 10G FAQ ANSWERS MAC
New node re-arps the world indicating a new MAC address for the IP. Simultaneously while the other instance attempts to manage updates.Ģ1) what are various IPs used in RAC? And How may IPs we need in RAC?Īns: Public IP, Private IP, Virtual IP, SCAN IPĪns: When a node fails, the VIP associated with it is automatically failed over to some other node and In a two-node environment, one instance attempts to manage updates The voting disk must reside on shared disk.Ĭheck /var/opt/oracle/ocr.loc or /etc/ocr.locġ7) If voting disk or OCR file got corrupte and don’t have backups so how toĪns: Will arise when two or more instances attempt to control a clusterĭatabase. Oracle RAC uses the voting disk to manage cluster membership by way of a healthĬheck and arbitrates cluster ownership among the instances Voting disk is akin to the quorum disk, which helps to avoid the split-brain Oracle Clusterware uses the voting disk to determine which instances are Your cluster.The daemon OCSSd manages the configuration info in OCR and maintains theĩ) What is Voting disk and how many files should be there?Īns: Voting Disk File is a file on the shared cluster system or a shared raw deviceįile.
The OCR must reside on shared disk that is accessible by all of the nodes in Information about any cluster database within the cluster. Maintains cluster configuration information as well as configuration The OCR also manages information about Oracle Clusterware resource profiles forĬustomized applications. RAC uses the interconnect for cache fusion (UDP) and inter-processĪns: RAC configuration information repository that manages information about theĬluster node list and instance-to-node mapping information. Heartbeat) and daemon communication between the clustered nodes.
It is easy to get the block image from the instance which has the block in itsĦ) What is the purpose of Private Interconnect?Ĭlusterware uses the private interconnect for cluster synchronization (network When a block of data is read from datafile by an instance within the clusterĪnd another instance is in need of the same block, Cache Fusion is the remote memory mapping of Oracle buffers, shared between the caches of participating nodes in the cluster. Server, scan, scan_listener, gns, vip, oc4j,GSDĪns: Transferring of data between RAC instances by using private network. Stand-alone database & RAC database background processes?Ĥ) What are structural changes in 11g R2 RAC?Īns: Grid & ASM are on one home, Voting disk & ocrfile can be on the ASM, SCAN, By using srvctl, we can mange diskgroups, home, ons, eons, filesystem, srvpool, Simultaneously while accessing a single database, thus providing clustering.Ģ) What are Oracle CLusterware and Daemon Processes and what they do?Īns: ocssd, crsd, evmd, oprocd, racgmain, racgimonģ) What are the special background processes for RAC (or) what is difference in
ORACLE 10G FAQ ANSWERS SOFTWARE
Oracle RAC allows multiple computers to run Oracle RDBMS software