Shared Server- Dedicated Server Configuration

Contents:- Shared Server, Dedicated Server Configuration.

Server Process

Oracle database creates server process to handle the request of user processes connected to an instance.

There are 2 Types of server process.

i)   Shared Server Process

Shared Server process can service more then one client connections.

Example:- Online Transaction Processing System.

ii)   Dedicated Server Process

Dedicated Server process can only service to one client. (Default)

Shared Server Configuration

Dispatcher Process

Dispatcher process comes in picture when you have configured shared server architecture. When user request connection to the database Dispatcher process handles user request and pass user connection to one common queue available in SGA. And then after that user request processed by server process.

Dispatcher supports multiple client connections concurrently.

Circuit

Each client is bound to a virtual circuit. Circuit is a piece of shared memory used by dispatcher for client database connection request and replies.

The dispatcher places a virtual circuit in a common queue when a request arrives.

Configure Shared Server

Shared_servers 

Specifies the number of shared server processes created when an instance is startup.

Shared_server_sessions   

Specifies the total number of oracle shared server user session to allow.

Dispatchers

Specifies the number of dispatchers that are initially started for a given protocol.

Circuits  

Specifies the total number of virtual circuits that are available for inbound and outbond network sessions.

Sql> alter system set shared_servers=6;

Sql> alter system set shared_server_session=100;

Sql> alter system set dispatchers =’(protocol=TCP) (dispatchers=2)(service=orcl)’;

Sql> alter system set circuits=2;

Now created service for client side connection with server type shared server.

Ex:- I created sharedorcl service for client connection.

NOW Check your server configuration by connecting to the same service that you created for shared server .

$> sqlplus sys/orcl@sharedorcl as sysdba

Sql> select distinct server from v$session.

You cannot shutdown database when any dispatcher process is running. So You have to make all parameter of shared server configuration to 0 to make it shutdown.