How load balancing is done in Oracle RAC?
Services coordinate their sessions by registering their workload, or the amount of work they are currently handling, with the local listener and the SCAN listeners.
What is scan in Oracle RAC?
Single Client Access Name (SCAN) is a feature used in Oracle Real Application Clusters. environments that provides a single name for clients to access any Oracle Database running. in a cluster. You can think of SCAN as a cluster alias for databases in the cluster.
What is LBA in Oracle RAC?
On Oracle RAC environment Load Balancing is something which is critical for distribution of connections between the servers we have. Load Balancing Advisory (LBA) is one of the key components for SCAN listener to decide the best instance for the new incoming connection request.
Which feature is used to load balance multiple connections opened with a database?
Scalability – A load balancer enables your applications to send traffic to multiple database servers, and allows the infrastructure to scale.
What is the difference between VIP and scan IP in Oracle RAC?
SCAN virtual IP addresses (VIPs) function like node VIPs. However, unlike node VIPs, SCAN VIPs can run on any node in the cluster. Clients (users or applications) that connect using a SCAN instead of a node VIP name or address do not have to update the list of node names or addresses in their local tnsnames.
What is the difference between client-side and server side load balancing in RAC?
Client-side load balancing balances the connection requests across the listeners. With server-side load balancing, the SCAN listener directs a connection request to the best instance currently providing the service by using the load balancing advisory.
How many scan listeners can we have for a 5 node cluster?
Scan is not configured as per number of cluster nodes, in a cluster there will be only one scan address resolving to three different ip’s for high avaliability purpose.
What is the difference between ELB and ALB?
An Application Load Balancer (ALB) only works at layer 7 (HTTP). It has a wide range of routing rules for incoming requests based on host name, path, query string parameter, HTTP method, HTTP headers, source IP, or port number. In contrast, ELB only allows routing based on port number.
What is difference between scan IP and VIP?
What is load balancing in Oracle RAC?
This feature is called load balancing. The local listener either directs the client to a dispatcher process (if you configured the database to use shared servers), or directs the client to a dedicated server process. There are two types of load balancing that you can implement for an Oracle RAC database: client-side and server-side load balancing.
How does Oracle Net handle the load of scan connections?
When clients connect using SCAN, Oracle Net automatically balances the load of client connection requests across the three IP addresses you defined for the SCAN, unless you are using EZConnect.
What is client side load balancing in Oracle Database?
Client-side load balancing is defined in your client connection definition (tnsnames.ora file, for example) by setting the parameter LOAD_BALANCE=ON. When you set this parameter to ON, Oracle Database randomly selects an address in the address list, and connects to that node’s listener.
What is load balancing advisory in Oracle WebLogic?
The LBA algorithm uses metrics sensitive to the current performance of services across the system. The load balancing advisory is deployed with key Oracle clients, such as a listener, the JDBC universal connection pool, OCI session pool, Oracle WebLogic Server Active GridLink for Oracle RAC, and the ODP.NET Connection Pools.