Usage and Configuration of the Oracle Shared Server pptx

5
Copyright © Oracle Corporation, 2002. All rights reserved.
Usage and Configuration
of the Oracle Shared Server
5-2
Copyright © Oracle Corporation, 2002. All rights reserved.
Objectives
After completing this lesson, you should be able to do
the following:
•
Identify the components of the Oracle Shared
Server
•
Describe the Oracle Shared Server architecture
•
Configure the Oracle Shared Server
•
Identify and explain usefulness of related data
dictionary views
5-3
Copyright © Oracle Corporation, 2002. All rights reserved.
Server Configurations
•
Dedicated server process
•
Shared server process
5-4
Copyright © Oracle Corporation, 2002. All rights reserved.
Dedicated Server Processes
Client Server
User

process
Server
process
PMON DBWnSMON LGWRCKPT ARCn
Instance
SGA
5-5
Copyright © Oracle Corporation, 2002. All rights reserved.
Oracle Shared Server
Shared server
processes
Database server
Client
Snnn
Snnn
User
process
User
process
Snnn
Instance
SGA
Dispatcher
D003
Dispatcher
D001
Dispatcher
D002
5-7
Copyright © Oracle Corporation, 2002. All rights reserved.

Benefits of Oracle Shared Server
•
Reduces the number of processes against an
instance
•
Increases the number of possible users
•
Achieves load balancing
•
Reduces the number of idle server processes
•
Reduces memory usage and system overhead
5-8
Copyright © Oracle Corporation, 2002. All rights reserved.
Using a Dedicated Server
with Oracle Shared Server
TEST.world =
(DESCRIPTION =
(ADDRESS =
(PROTOCOL = TCP)
(HOST = stc-sun02)
(PORT = 1521)
)

(CONNECT_DATA=(SERVICE_NAME=TEST.us.oracle.com)
(SERVER=DEDICATED)
)
)
5-9
Copyright © Oracle Corporation, 2002. All rights reserved.

2
1
Database server
Client
Connecting
User
process
User
process
Listener
Dispatcher
process
D001
Dispatcher
process
D002
3
5-10
Copyright © Oracle Corporation, 2002. All rights reserved.
PMON DBWn
SMON
LGWRCKPT ARCn
Request
Queue
Response queue
for (D002)
Response queue
for (D003)
Instance
SGA

Processing a Request
Shared server
processes
Database server
client
Snnn
Snnn
User
process
Listener
Dispatcher
D002
Dispatcher
D003
Snnn
Response queue
for (D001)
4
5
3
2
1
6
Dispatcher
D001
User
process
5-12
Copyright © Oracle Corporation, 2002. All rights reserved.
Oracle Shared Server: User session data is held in

the SGA

SGA
User
session
data
Cursor
state

Shared pool
and other
memory
structures
Stack
space

PGA
Dedicated Server: User session data is kept in the
PGA
The SGA and PGA

SGA

Shared pool and other
memory structures
Stack
space
User
session
data

Cursor
state

PGA
5-13
Copyright © Oracle Corporation, 2002. All rights reserved.
Configuring Oracle Shared Server
•
Required initialization parameters
–
DISPATCHERS
–
SHARED_SERVERS
•
Optional initialization parameters
–
MAX_DISPATCHERS
–
MAX_SHARED_SERVERS
–
CIRCUITS
–
SHARED_SERVER_SESSIONS
5-14
Copyright © Oracle Corporation, 2002. All rights reserved.
DISPATCHERS
Specifies the number of dispatchers initially started for
a given protocol
DISPATCHERS = "(PROTOCOL=TCP)(DISPATCHERS=2)\
(PROTOCOL=IPC)(DISPATCHERS=1)"

Dispatcher
D002
TCP/IP
Dispatcher
D003
IPC
Dispatcher
D001
TCP/IP
5-16
Copyright © Oracle Corporation, 2002. All rights reserved.
MAX_DISPATCHERS
•
Specifies the maximum number of dispatcher
processes that can run simultaneously
•
Issues the ALTER SYSTEM command to add more
dispatchers than initially started
MAX_DISPATCHERS = 5
Dispatcher
D002
TCP/IP
Dispatcher
D003
IPC
Dispatcher
D001
TCP/IP
Dispatcher
D004

Dispatcher
D005
5-18
Copyright © Oracle Corporation, 2002. All rights reserved.
SHARED_SERVERS
Specifies the number of server processes created
when an instance is started up
SHARED_SERVERS = 6
S001
S002
S003
S004
S005
S006
5-20
Copyright © Oracle Corporation, 2002. All rights reserved.
MAX_SHARED_SERVERS
•
Specifies the maximum number of shared servers
that can be started
•
Allows shared servers to be allocated dynamically
based on the length of the request queue
MAX_SHARED_SERVERS = 10
S001
S002
S003
S004
S005
S006

S007
S008
S009
S010
5-21
Copyright © Oracle Corporation, 2002. All rights reserved.
CIRCUITS
•
Specifies the total number of virtual circuits that
are available for inbound and outbound network
sessions
•
Contributes to total SGA size
CIRCUITS = 100
5-22
Copyright © Oracle Corporation, 2002. All rights reserved.
SHARED_SERVER_SESSIONS
•
Specifies the total number of Oracle Shared Server
user sessions to allow
•
Setting this parameter enables you to reserve user
sessions for dedicated servers
SHARED_SERVER_SESSIONS = 100
5-23
Copyright © Oracle Corporation, 2002. All rights reserved.
Related Parameters
Other initialization parameters affected by Oracle
Shared Server that may require adjustment:
•

LARGE_POOL_SIZE
•
SESSIONS
5-25
Copyright © Oracle Corporation, 2002. All rights reserved.
•
Verify that the dispatcher has registered with the
listener when the instance was started by issuing:
•
Verify that you are connected using shared servers
by making a single connection then query
V$CIRCUIT view to show one entry per shared
server connection.
Verifying Setup
$ lsnrctl services
5-27
Copyright © Oracle Corporation, 2002. All rights reserved.
Dynamic Views
•
V$CIRCUIT
•
V$SHARED_SERVER
•
V$DISPATCHER
•
V$SHARED_SERVER_MONITOR
•
V$QUEUE
•
V$SESSION

5-28
Copyright © Oracle Corporation, 2002. All rights reserved.
Summary
In this lesson, you should have learned how to:
•
Identify the components of the Oracle Shared
Server
•
Describe the Oracle Shared Server architecture
•
Configure the Oracle Shared Server
•
Identify and explain usefulness of related data
dictionary views
5-29
Copyright © Oracle Corporation, 2002. All rights reserved.
Practice 5 Overview
This practice covers the following topics:
•
Configuring Oracle Shared Server
•
Defining LOCAL_LISTENER for instance
registration
•
Using the Listener Control utility to verify services
•
Verifying shared server configuration and
performance using V$ views
•
Verifying instance registration