Shared vs Dedicated

how do we check weather database is running in Shared or Dedicated mode? and how to switch between modes?

http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96521/manproc.htm#8715

Similar Messages

Shared versus dedicated connections in the fragmentation of shared pool mem

Hi,
I have a old Oracle 8.1.7 database server.
I have a legacy application with no source code. This application don't use memory efficiently (no bind variables, etc.) , ie memory becomes fragmented.
I know that exists two ways to connect the database (dedicated and shared)
Based on this, I want to know which of the two options creates more fragmentation. I know that recommendation is to use dedicated connection, but I'm not sure if this is recomendation is applicable in this particular environment.
Thanks in advance.

Whether you use shared or dedicated connections makes no difference for fragmentation in the shared pool. Whether your hard parse or do not hard parse does matter.
Measures you can take
- make sure often used packages like dbms_standard are pinned in the shared pool using a startup trigger
- set session_cached_cursors to 50 or 100. This will reduce parsing.
Sybrand Bakker
Senior Oracle DBA

Shared and Dedicated server modes

Hi,
We have been having some issues with connections and listeners. Please find here... Link [Post1|http://forums.oracle.com/forums/message.jspa?messageID=3665455] and Link [Post2|http://forums.oracle.com/forums/message.jspa?messageID=3677914].
Despite this help from this forum, I still face some problem configuring listener in both Shared and Dedicated server modes.
Pls find the below the problem...
Two listeners namely, LSNR1 and LSNR2 have been started.
listener.ora:
LSNR2 =
(DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = dbdev.website.org)(PORT = 1522))
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
SID_LIST_LSNR2 =
(SID_LIST =
    (SID_DESC =
      (SID_NAME = TESTDB)
      (ORACLE_HOME = /u02/app/oracle)
LSNR1 =
(DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = dbdev.website.org)(PORT = 1521))
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
SID_LIST_LSNR1 =
(SID_LIST =
    (SID_DESC =
      (SID_NAME = TESTDB)
      (ORACLE_HOME = /u02/app/oracle)
)LSNR1 works with both Shared and Dedicated configurations, whereas LSNR2 neither DEDICATED nor SHARED configurations...
Here is the TNS names entry at the client (for LSNR2)...
serv2=
(DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = xxx.xxx.xxx.xxx)(PORT = 1522))
    (CONNECT_DATA =
      (SERVICE_NAME=DEDICATED)
)When I try to connect using this, it says
+ ORA-12514: TNS: Listener does not know of service requested in connect descriptor +
Pls help.
Thanks,
Aswin.

Aswin,
I didnt see the other posts but the error is fairly simple,
>
ORA-12514:
TNS:listener does not currently know of service requested in connect descriptor
Cause:     The listener received a request to establish a connection to a database or other service. The connect descriptor received by the listener specified a service name for a service (usually a database service) that either has not yet dynamically registered with the listener or has not been statically configured for the listener. This may be a temporary condition such as after the listener has started, but before the database instance has registered with the listener.
Action:
- Wait a moment and try to connect a second time.
- Check which services are currently known by the listener by executing: lsnrctl services <listener name>
- Check that the SERVICE_NAME parameter in the connect descriptor of the net service name used specifies a service known by the listener.
- If an easy connect naming connect identifier was used, check that the service name specified is a service known by the listener.
- Check for an event in the listener.log file.
>
So check what you are passing in the connection string.
HTH
Aman....

Shared and Dedicated Server...

Dear All,
Can anybody tell what's the difference between shared and dedicated server? Our database is Oracle 9.0.1 in Windows 2003. Our total session is around 200. Our server is dedicated server. What will be the benefit if we change our database to shared server for specific users???
Shared pool size = 728MB
Buffer Cache = 592MB
Java pool = 104MB
Large pool = 60MB
There is no pga_aggregate_target in our database. Is the configuration ok for more than 200 users??? Most of the times we get 'out of process memory error'. What should we do in this situation??? Plz suggest.

mrashid07 wrote:
Can anybody tell what's the difference between shared and dedicated server?Dedicated server is the default. It means that each and every user session is serviced by a dedicated Oracle server process. 200 user connections? 200 dedicated server processes.
On Windows these are however threads inside the physical oracle.exe process (and not actual separate process images like on Unix/Linux for example). A standard thread on Windows needs around 2MB of kernel space. So 200 threads, for 200 dedicated server connections, need 200 x 2MB RAM.
Shared server works differently. A pool of dispatchers and shared servers are created. The dispatcher processes deals with the communication between the Oracle client and the Oracle instance. A dispatcher places client requests on a virtual circuit. These requests are picked up by idle shared server processes and processed. The results are send back to the client via a dispatcher process.
So instead of having 200 dedicated server processes to service 200 users, you can for example use 5 dispatcher processes and 30 shared server processes to service the 200 sessions of those 200 users. In this case 35 processes are used that translates into 35 threads at a basic 2MB RAM cost per thread. (also note that the UGA now moves from the Oracle PGA to the Oracle SGA and the SGA needs to be sized accordingly).
However, should such a user session send a long and complex request, that will tie up that shared server for a long time.. and this is bad. When the shared server process is busy, it cannot service any new requests. When all the shared servers in the pool are busy, no new request can be serviced. So you want the requests from the clients to be short and sweet - with a shared server not spending more than a few seconds per request.
So typically OLTP requests are fine for shared servers.. OLAP requests not.
Our database is Oracle 9.0.1 in Windows 2003. You should have been on 9.2.0.7 (last 9i patch set). You should currently being in the process of upgrading to 11gR2. 9i is basically an unsupported product. It is not a good idea to use an unsupported product in production. Even worse when you are not using the latest patchset for that product.
As for using Windows.. why? 32bit is old hat. 64bit CPUs are standard even in today's desktop PCs. Consider using Linux instead. It is Open Source, is free ito purchasing (you only pay for support and maintenance) and it has had de-facto 64bit support for many years now. There's no need to hack the operating system, like Windows with its AWE extensions to address more than 4GB RAM.

Nexus 7009 bandwidth allocation per port in shared and dedicated mode:

We have 7009 with following I/O modules:
N7K-F248XP-25E --
N7K-C7009-FAB-2 - qty 3
N7K-SUP2
I would like to know that each port of N7K-F248XP-25E will get how much bandwidth in shared mode. if we are using only one port group with 4 ports each port with 10gbps is it possible in shared mode to get 40gbps in one port group.
Thanks

Hi,
I'm not sure there is such a thing as shared and dedicated mode on the N7K-F248XP-25E I/O module. I don't have one to test with, but you can see this if you execute the command show interface capabilities on your switch. If you look for the "Rate mode" line in the output it will show as dedicated or dedicated/shared. I suspect the ports on this module will all show as dedicated.
That said, with your configuration there is potential for some level of over-subscription.
The N7K-F248XP-25E I/O module uses a Switch on Chip (SoC) architecture with the 48-ports 10-GE ports connected via 12 SoCs, so the "port grouping" is ports 1-4=SoC 1, 5-8=SoC 2 etc.
Each of the SoC has 40-Gbps of capacity to the switch fabric ASIC, which in turn has up to 550-Gbps capacity to the switching fabric. The 550-Gbps fabric capacity is the maximum based on 110-Gbps per slot, per fabric to the installed Fabric 2 Modules. To realise this capacity there must be five Fabric 2 modules installed in the chassis.
From the hardware list you've supplied, you only have three Fabric 2 modules installed and as such you can only achieve a maximum of 330-Gbps per I/O module slot. What this means is that you have 480-Gbps host facing bandwidth, but 330-Gbps Fabric facing bandwidth, so a potential 1.45:1 over-subscription.
You can reduce the over-subscription into the switch fabric by adding additional Fabric 2 modules.
Regards

Can oracle work in shared and dedicated mode at the same time?

Hi All,
can oracle work in shared and dedicated mode at the same time?
Thanks

A database can work only in one mode at a time.
If the database is started in Dedicated Mode then it can not run in the Shared Mode. If you need to run it in the Shared Mode, bring down the Database , change DISPATCHERS, SHARED_SERVER, SHARED_SERVER_SESSIONS parameters in initfile and bring up the database to run it in Dedicated Mode.
But there is one catch here, if you have started the database in Shared Server Mode even then you can make a Dedicated connection to server.
Thanks!
M-

Shared vs dedicated server

Any reason to select one over the other?
The reason I'm asking is because two texts that I have which were not written by Oracle suggest using dedicated server processes, while all of the Oracle-written texts suggest shared (although I did finally find a note which mentions "NOTE:...if your machine has plenty of memory to support dedicated servers, you should use that approach. In this situation, performance is likely to be better.")
-cf

Actually it depends upon the requirement.
Shared and dedicated server environment are meant for different purposes and requirements.
If server process is ideal for long time than same server process can be used to server other clients. Eg. On a web site user searched for Oracle Tuning books and now he is taking time to go through the title, contents, price. Your Server process is ideal during this time where as it can used to server other clients.
Similarly if I use dedicated server process for batch processing it will be more effective than shared server because there is no ideal time.
It is not true shared server requires more resources or dedicated server requires more memory. It will depend upon the proper utilization of resources. With the same given resources dedicated server environment may work more efficiently for one scenario and in the another scenario with the same resources a shared server works very well.
Manu

Shared and Dedicated Mode in Oracle 8i

Can any one describe what is basic difference when we install Oracle8i in dedicated and Shared modes. I have to create Oracle8i Database for not more 150 users. Actually less then 20 users might be accessing database but in future it can go up to maximum 100.

WIthout understanding your application and hardware in some detail, it is impossible to say which mode is better-- and that's without accounting for a mixed-mode setup where some connections are shared and some are dedicated.
If there are going to be 20 simultaneous connections, dedicated server is almost always preferred. If you start to get up to 100 simultaneous connections, depending on your hardware, it may become appropriate to use shared server. If you have a high-end multi-CPU machine, it will easily handle 100 connections. If you have a low-end single-processor Windows server, you might have problems with dedicated server.
OLTP systems tend to be more amenable to shared server than DSS systems, because sessions spend a lot of time idle in the former type of application.
Justin
Distributed Database Consulting, Inc.
http://www.ddbcinc.com/askDDBC

How to check SAN disk is shared or dedicated disk

Hi,
I would like to know,
From server side Is there way to identify SAN disk is shared between different nodes or its dedicated SAN disk. (Without reaching Storage team).
Regards,
Manjunath Sullad

Hi Mandy,
Thanks for the reply, Yeah we can get disk details from get-disk,
I am looking specific related to disk is shared or not
You can try to use SCSIcmd utility from Symantec. It would allow you to log and clear SCSI-2 & SCSI-3 ("old school" and persistent) reservations. See:
How to use the SCSIcmd utility to perform various SCSI-2 and SCSI-3 reservation related actions
http://www.symantec.com/business/support/index?page=content&id=TECH72086
Start with obvious logging and if disk is actually shared between multiple hosts it would have non-zero reservation tables. Example of the output:
Syntax Example: scsicmd -d14 -sscsi_reserved_status
Below are some example outputs of what will be seen with this command depending on the reservation type and status:
SCSI-2 Output when there is a reservation on the disk:
Harddisk14
Scsi Address
Length : 0x8
PortNumber : 0x2
PathId : 0x1
TargetId : 0x2
Lun : 0x45
Harddisk14 is currently SCSI-2 reserved by SCSI Address (0x2, 0x1, 0x0, 0x1) of the computer: MTV2850-07.
SCSI-3 Output when there is a reservation on the disk
Harddisk14
Scsi Address
Length : 0x8
PortNumber : 0x2
PathId : 0x1
TargetId : 0x2
Lun : 0x45
Harddisk 14 has SCSI-3 key(s) registered.
SCSI3 registered keys on harddisk14
Key: 7856341278563412
Key: 7856341278563412
Harddisk14 is currently under SCSI-3 reservation
SCSI3 reservation holder key on harddisk14
Key: 7856341278563412
Harddisk14 is currently being SCSI-3 reserved on the computer: MTV2850-07.
SCSI2 or SCSI3 output when there is no reservation on the disk:
Harddisk14
Scsi Address
Length : 0x8
PortNumber : 0x2
PathId : 0x1
TargetId : 0x2
Lun : 0x45
Harddisk14 of the computer: MTV2850-07 is not under any SCSI reservation.
Good luck :)
Cheers,
Anton Kolomyeytsev [MVP]
StarWind Software Chief Architect
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Db in shared or dedicated mode

Hello,
on DB 11.2.0.1, we have parameter SHARED_SERVERS set to 1 (also, DISPATCHERS parameter), but a connection is made through tns with a definition containint '(SERVER = DEDICATED)'.
Is this database running in shared mode?
AFAIK, it's only necessary to set shared_servers to a value greater than 0, and it's in shared mode... am I right?
regards

If you specific (SERVER = DEDICATED) in connect string or sqlnet.ora dedicated_server = on then all connections are DEDICATED. In v$session column server give you the process using shared connection (value SHARED or NONE).
HTH
Antonio NAVARRO
Remember some connections (rman, batch process, etc.) must no be in shared.

Shared and dedicated servers in 10g

Hi,
My database is on 9i solaris 10. I am giving both dedicated and shared servers to the users. I am in the process to upgrade to 10g. Anything I need to keep in mind with respect to dedicated and shared servers?
Thanks & Regards

http://download-uk.oracle.com/docs/cd/B19306_01/server.102/b14231/manproc.htm#i1006089

Shared server/dedicated server process doubt?

when oracle database is not configured for shared server is it compulsay to include SERVER=DEDICATED clause in the connect descriptor.?
Thankx.

Hi,
is it compulsay to include SERVER=DEDICATED clause in the connect descriptor.?No, the MTS is defined at startup time, via the MTS parms.
Here is a sample of shared server definition in the init.ora file:
# Multi-threaded Server parameters
local_listener="(address_list=
(address=(protocol=tcp)(host=sting.janet.com)(port=1521))
MTS_MAX_DISPATCHERS=5
MTS_MAX_SERVERS=20
MTS_DISPATCHERS="(ADDRESS=
(PROTOCOL=tcp)(HOST=sting.janet.com))(DISPATCHERS=3)
service_names=testb1
http://www.dba-oracle.com/unix_linux/epc_disabled.htm
However, be aware that the MTS is not a panacea, especially at times when you want to invoke a dedicated process for your program. For Pro*C programs and I/O-intensive SQL*Forms applications, or any batch processes that have little idle time, you may derive better performance using a dedicated listener process. For shops that segregate task into online and batch modes, the DBA sometimes create separate listeners—one with the MTS and another for dedicated connections.
Hope this helps. . . .
Donald K. Burleson
Oracle Press author

Shared or dedicated server

Dear all,
Would you tell me how to check out whether a database instance is a shared or a dedicated server?
Thanks

Firstly, thanks for your help.
I posted my problem in another thread. The problem is listed below.
BTW, when I create a new instance as dedicated server. I don't have this problem anymore.
So I wonder it is setting shared server is different from setting dedicated server.
Previous post:
===============================================================
I have a problem of network configuration. I installed an Oracle 8.1.7 standard edition database server. I can logon using sqlplus at local database machine without any problem. I can logon as system using sqlplus in a remote workstation, but I cannot logon using sqlplus as a normal user in a remote workstation. The normal user is granted connect role and create session system privilege.
Also, once I have a failed logon using normal user I cannot logon as system anymore until I restart the listener on the db server.
Please help. I don't have this problem on 9i, 10g.
The error is demostrated below:
===============================================================
SQL*Plus: Release 9.2.0.1.0 - Production on Fri Feb 24 21:45:11 2006
Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.
Connected to:
Oracle8i Release 8.1.7.4.0 - Production
JServer Release 8.1.7.4.0 - Production
SQL>
SQL> connect ars
Enter password: *****
ERROR:
ORA-12560: TNS:protocol adapter error
Warning: You are no longer connected to ORACLE.
SQL> connect system
Enter password: *******
ERROR:
ORA-12560: TNS:protocol adapter error
===============================================================
The listener.ora, sqlnet.ora in the server is listed below:
===============================================================
# LISTENER.ORA Network Configuration File: /u01/app/oracle/product/8.1.7/network/admin/listener.ora
# Generated by Oracle configuration tools.
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 172.20.2.18)(PORT = 1521))
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC))
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = /u01/app/oracle/product/8.1.7)
(PROGRAM = extproc)
(SID_DESC =
(GLOBAL_DBNAME = stustg.urban.com.hk)
(ORACLE_HOME = /u01/app/oracle/product/8.1.7)
(SID_NAME = stustg)
===============================================================
# SQLNET.ORA Network Configuration File: /u01/app/oracle/product/8.1.7/network/admin/sqlnet.ora
# Generated by Oracle configuration tools.
#SQLNET.AUTHENTICATION_SERVICES= (NONE)
NAMES.DIRECTORY_PATH= (TNSNAMES)
===============================================================

Shared or Dedicated server mode

My database is configured like:
9i Release2, Enterprise edition, OLTP, DEDICATED server mode!
I have more than 40 users who connect to db through WAN.
Is this good selection, I meen on server mode, or is better way to use SHARED s.mode. And way?!
Also where could I see which server mode of db is installed?
Thanks!

If we are talking about 40 physical end users, I wouldn't consider shared server mode. Shared server is ideal when you have so many users that the server would simply fall over if it tried to spawn that many dedicated connections.
Justin
Distributed Database Consulting, Inc.
http://www.ddbcinc.com/askDDBC

Shared to Dedicated

I have created a db with shared server mode and I want to convert it into dedicated for better performance. How do I do that and what parameters to be changed?
Thanks!

From Oracle doc,
http://download.oracle.com/docs/cd/B19306_01/server.102/b14231/manproc.htm#i1010000
Disabling Shared Servers
You disable shared server by setting SHARED_SERVERS to 0. No new client can connect in shared mode. However, when you set SHARED_SERVERS to 0, Oracle Database retains some shared servers until all shared server connections are closed.
also if you any of your application or TNSNAMES.ora has
SERVER=SHARED
in connect descriptor make sure change to DEDICATED or remove the line.

Shared vs Dedicated

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