INTRODUCTION TO ORACLE Lynnwood Brown System Managers LLC Client-Server – Lecture 4 Copyright System Managers LLC 2007 all rights reserved.

CLIENT/SERVER and NET8 NET8 is used to implement Oracle’s client server architecture. Operates at OSI layers 5 and 6. Supports different types of protocols including TCP/IP, SPX/IPX and drivers such as ODBC and JDBC Must be installed on both the client and the server machines. NET8 drivers are linked into the Oracle executables when NET8 is installed Machines should be able to “ping” each other

CLIENT/SERVER and NET8 Copyright System Managers LLC 2007 all rights reserved.

CLIENT/SERVER and NET8 NET8 requires the configuration files LISTENER.ORA FILE on the server and TNSNAMES.ORA file on the client machine Applications connect to the database using an alias. The alias is defined in the TNSNAMES.ORA file The database server process TNSLSNR (Listener) connects the user application to the database. Net8 services are invoked using the utility “LSNRCTL”. Options include START, STOP, RELOAD AND STATUS

CLIENT/SERVER and NET8

LISTENER.ORA FILE CONTENTS LISTENER= (ADDRESS_LIST= (ADDRESS= (PROTOCOL = IPC) (KEY = v10g1)) (ADDRESS= (PROTOCOL = TCP) (HOST = ) (PORT = 1521))) SID_LIST_LISTENER= (SID_LIST =(SID_DESC =(SID_NAME = v10g1) (ORACLE_HOME = /usr/oracle/product/10g1))) Copyright System Managers LLC 2007 all rights reserved.

CLIENT/SERVER and NET8 TNSNAMES.ORA FILE CONTENTS v10g= (DESCRIPTION= (ADDRESS= (PROTOCOL=TCP) (HOST= ) (PORT=1521) ) (CONNECT_DATA= (SID=v10g))) Copyright System Managers LLC 2007 all rights reserved.

CLIENT/SERVER and NET8 Supports server level tracing through additions to the SQLNET.ORA file (NET8). TRACE_LEVEL_SERVER=16 TRACE_FILE_SERVER=SERVER Supports listener level tracing through additions to the LISTENER.ORA file. TRACE_LEVEL_LISTRENER=16 TRACE_FILE_LISTENER=TNSLSNR.

CLIENT/SERVER and NET8 Supports client level tracing through modifications to the SQL*NET.ORA file. TRACE_LEVEL_CLIENT=16 TRACE_FILE_CLIENT= CLIENT TRACE_DIRECTORY_CLIENT = C:\TRACE Remember to turn tracing off after capturing the desired session information Copyright System Managers LLC 2007 all rights reserved.

CLIENT/SERVER and NET8 Database Links Used to link remote databases (access one database from another database Requires Net8 installation and configuration Requires account on the remote machine CREATE DATABASE LINK MY_LINK CONNECT TO SCOTT IDENTIFIED BY TIGER USING ‘ALIAS’; Accessing data via a database link SELECT * FROM

NET8 and Multi-Threaded Server

The benefits of the Multi-Threaded Server include: Reduce the number of processes running against the instance Reduce the number of idle-server processes Reduce memory usage and system overhead A dedicated server may be required in to improve performance (Add SERVER=DEDICATED to TNSNAMES.ORA file)

NET8 and Multi-Threaded Server ######################################################## # Multi-Threaded Configuration Parameters ######################################################## LOCAL_LISTENER = listener.world MTS_SERVICE = 10g MTS_DISPATCHERS = "(protocol=tcp)(dispatchers=3)" MTS_MAX_DISPATCHERS = 5 MTS_SERVERS = 6 MTS_MAX_SERVERS = 10 After editing the INIT.ORA file with the above parameters, restart the database for the parameters to take effect. Copyright System Managers LLC 2007 all rights reserved.

NET8 and Multi-Threaded Server There will be 'ora_sNNN_SID' and 'ora_dNNN_SID' for the shared servers and dispatchers that have been configured. Check the output of 'lsnrctl services' to ensure that all dispatchers (or pre-spawned servers) are active MTS DATA DICTIONARY VIEWS V$SHARED_SERVER - Shared server names and status V$DISPATCHER - Dispatcher names and status V$MTS – Maximum and minimum MTS sessions Copyright System Managers LLC 2007 all rights reserved.

CLIENT/SERVER and NET8 Installed on client and server machine Supports network tracing Supports ODBC and JDBC Access remote databases using “Database Links” MTS saves system resources but may introduce performance problems Copyright System Managers LLC 2007 all rights reserved.