Tuning the Oracle Shared Server pot

8
Copyright © Oracle Corporation, 2002. All rights reserved.
Tuning the Oracle Shared Server
8-2
Copyright © Oracle Corporation, 2002. All rights reserved.
Objectives
After completing this lesson, you should be able to do
the following:
•
Identify issues associated with managing users in
an Oracle Shared Server environment
•
Configure the Oracle Shared Server environment
to optimize performance
•
Diagnose and resolve performance issues with
Oracle Shared Server processes
8-3
Copyright © Oracle Corporation, 2002. All rights reserved.
Overview
System Global Area
Oracle background processes
Dispatcher processes
Database server
Listener
Client
Shared
server
processes
Oracle server
code program

interface
Request queue
Response queues
8-4
Copyright © Oracle Corporation, 2002. All rights reserved.
Oracle Shared Server Characteristics
•
Enables users to share processes
•
Supports Oracle Net functionality
•
Increases the number of concurrent users
•
Useful on servers with remote clients
•
CPU overhead could possibly increase for each
individual user request
8-5
Copyright © Oracle Corporation, 2002. All rights reserved.
Monitoring Dispatchers
•
Use the following dynamic views:
–
v$shared_server_monitor
–
v$dispatcher
–
v$dispatcher_rate
•
Identify contention for dispatchers by checking:

–
Busy rates
–
Dispatcher waiting time
•
Check for dispatcher contention.
•
Add or remove dispatchers while the database
is open.
8-7
Copyright © Oracle Corporation, 2002. All rights reserved.
Monitoring Shared Servers
•
Oracle Shared Servers are started up dynamically.
•
However, you should monitor the shared
servers by:
–
Checking for shared server process contention
–
Adding or removing idle shared servers
8-9
Copyright © Oracle Corporation, 2002. All rights reserved.
Monitoring Process Usage
The v$circuit view displays:
•
Server address
•
Dispatcher address
•

User session address
8-10
Copyright © Oracle Corporation, 2002. All rights reserved.
Shared Servers and Memory Usage
•
Some user information goes into the shared pool.
•
To reduce the load on the shared pool set a
large pool.
•
Overall memory demand is lower when using
shared servers.
•
Shared servers use the user global area (UGA)
for sorts.
8-11
Copyright © Oracle Corporation, 2002. All rights reserved.
Troubleshooting
Possible causes of problems with the shared server
include the following:
•
The database listener is not running.
•
The Oracle Shared Server initialization parameters
are set incorrectly.
•
The dispatcher process has been killed.
•
The DBA does not have a dedicated connection.
•

The PROCESSES parameter is too low.
8-12
Copyright © Oracle Corporation, 2002. All rights reserved.
Obtaining Dictionary Information
Dynamic performance views:
•
v$circuit
•
v$dispatcher
•
v$dispatcher_rate
•
v$queue
•
v$shared_server_monitor
•
v$session
•
v$shared_server
8-13
Copyright © Oracle Corporation, 2002. All rights reserved.
Summary
In this lesson, you should have learned how to:
•
Describe the Oracle Shared Server as a resource-
sharing configuration
•
List some situations in which it is appropriate to
use the Oracle Shared Server
•

Monitor dispatcher and server usage
•
Troubleshoot Oracle Shared Server configuration