Shared server connections.

we are running a third party application with an 11g database shared server configuration and OAS 10gR2. Dispatchers set to 10 and shared servers set to 100. When the database instance is started, the 100 shared server and 10 dispatcher sessions start up and I can see these processes with ps -ef. They show as ora_s0* processes and ora_d0* respectively.
At some point after the startup of the application, it establishes a connection pool of 100 sessions (10 per dispacher). The process Id of these sessions correspond to the pids of the dispatcher processes not the shared server processes.
The 100 sessions in the connection pool remain idle until a user logs on to the system. When a successful login is made, I see that about 8 of the idle sessions become active and remain so until the user finishes with the application and logs out.
Questions :
1. Is there a query I can do to show me the shared sherver sessions i.e. ora_s0* being used?
3. Are the 100 sessions (in the connection pool) really the shared server sessions even though they show up with the pid of the parent dispatcher?
2. I need to record the number of connections being made to the system over a period and how long each user is connected for, could you suggest the best method (including queries) of going about this task?
Thank you.

user8869798 wrote:
we are running a third party application with an 11g database shared server configuration and OAS 10gR2. Dispatchers set to 10 and shared servers set to 100. When the database instance is started, the 100 shared server and 10 dispatcher sessions start up and I can see these processes with ps -ef. They show as ora_s0* processes and ora_d0* respectively.
At some point after the startup of the application, it establishes a connection pool of 100 sessions (10 per dispacher). The process Id of these sessions correspond to the pids of the dispatcher processes not the shared server processes.
The 100 sessions in the connection pool remain idle until a user logs on to the system. When a successful login is made, I see that about 8 of the idle sessions become active and remain so until the user finishes with the application and logs out.
Questions :
1. Is there a query I can do to show me the shared sherver sessions i.e. ora_s0* being used?You can use v$shared_server s, v$circuit c, v$session n
with this as joining condition- s.circuit = c.circuit and c.saddr = n.saddr
3. Are the 100 sessions (in the connection pool) really the shared server sessions even though they show up with the pid of the parent dispatcher? you can query server column of v$session to check if they are shared or dedicated.
2. I need to record the number of connections being made to the system over a period and how long each user is connected for, could you suggest the best method (including queries) of going about this task?
I see only ash the option for you, else you need to have your own scheduled script/procedure that would gather that information.
Thank you.

Similar Messages

Dedicated Server Connection Vs Shared Server Connection

Hi Gurus,
I have few doubts regarding Dedicated Server Connection Vs Shared Server Connection -
1) How do I know which connection mechanism is configured in my system.
2) Which connection faster and reliable.
3) Is there any risk to using shared server connection?
4) Which concept is new comparatively?
5) It is possible to restrict specific user for Dedicated Server Connection and other for Shared Server Connection in a same database.
Regards,
Atanu

AChatterjee wrote:
Thanks for your post.... but still i have doubt on below points -
1) How do I know which connection mechanism is configured in my system.Search for dispatcher parameter (both words in the search box) in the docs.
2) It is possible to restrict specific user for Dedicated Server Connection and other for Shared Server Connection in a same database.You might be able to do something like this by using the RULE parameter with cman, limiting specific users (via local security setups) to specific client IP's and forcing them to particular service names. This is a net services issue, so does not conflict with what Billy said. It assumes you control whether your users will query the db appropriately, too. Many apps don't do that right.

Problems establishing a Shared Server connection

I am trying to establish a connection to a shared server on a test database. The database is 10.2.0.4 and runs on Solaris 10. Here are some setting for my init file, and I think the last two do not need to be set.
# Shared Server
dispatchers="(PROTOCOL=TCP) (SERVICE=DBA10XDB)"
shared_servers=5
shared_server_sessions=20
I connect from my client which uses a tnsnames.ora file and does NOT specify a dedicated server. Here is the result of LSNRCTL SERVICES:
LSNRCTL for Solaris: Version 10.2.0.4.0 - Production on 22-MAR-2011 10:07:04
Copyright (c) 1991, 2007, Oracle. All rights reserved.
Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))
Services Summary...
Service "BUILDTST" has 1 instance(s).
Instance "BUILDTST", status READY, has 1 handler(s) for this service...
Handler(s):
"*DEDICATED*" established:1 refused:0 state:ready
LOCAL SERVER
Service "BUILDTST_XPT" has 1 instance(s).
Instance "BUILDTST", status READY, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:1 refused:0 state:ready
LOCAL SERVER
Service "DBA10XDB" has 1 instance(s).
Instance "BUILDTST", status READY, has 1 handler(s) for this service...
Handler(s):
"*D000*" established:0 refused:0 current:0 max:992 state:ready
DISPATCHER <machine: dbtest, pid: 20864>
(ADDRESS=(PROTOCOL=tcp)(HOST=dbtest)(PORT=50059))
The command completed successfully
V$SESSION shows the connections to be DEDICATED. Any suggestions as to what I may be doing incorrectly? Reading all I can find on this seems to indicate all I need to do is have DISPATCHERS and SHARED_SERVERS set and then connections will automatically be shared server connections.

Thanks. Your post helped me get things straightened out. After changing my tnsnames file I was getting an ORA-12520. Hmmm. I then noticed the (SERVICE=DBA10XDB) on my DISPATCHERS parameter, which was there by default when Oracle configured the init file initially. I removed that and it worked.
Then I was able to get connections to the shared server with and without the SERVER=SHARED setting. I knew I had read that Oracle will default to shared server if not specified, but your post indicated that a client connection can be forced to use the shared server, even when no dispatchers are registered. I think mine was not registered to my instance due to the (SERVICE=DBA10XDB) setting. If there are no registered dispatchers the connection request is rejected.

I cant get a shared server connection

Hello, I configured the shared server option on my computer, but every time I connect, I get 'DEDICATED' for the server column in v$session. Can anyone tell me how to establish shared server connex from your own machine please?
I am connecting like sqlplus scott/[email protected]
and it connects back to my machine (I think) with no error msg, but still I am getting DEDICATED for server in v$session, it is driving me nuts.
Thanks.
Collin.

So when you're in an area with public and open wifi networks, you cannot go to settings/wifi/choose a network?

Data Guard Primary having shared server connections

Hi fellows,
I am configuring dataguard from RAC primary to RAC standby. The RAC primary is using shared server mode. The primary server tnsnames.ora looks like this:
HWPR =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = hwpr-vip1)(PORT = 1521))
(ADDRESS = (PROTOCOL = TCP)(HOST = hwpr-vip2)(PORT = 1521))
(LOAD_BALANCE = yes)
(CONNECT_DATA =
(SERVER = SHARED) <<<<< this is my concern
(SERVICE_NAME = hwpr)
while documentation says that for dataguard dedicated server is required. so what changes do i need to do. Is it only required to changed the tnsnames.ora from shared to dedicated or any other init parameter is also required to be changed.

user11983096 wrote:
Hi fellows,
I am configuring dataguard from RAC primary to RAC standby. The RAC primary is using shared server mode. The primary server tnsnames.ora looks like this:
HWPR =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = hwpr-vip1)(PORT = 1521))
(ADDRESS = (PROTOCOL = TCP)(HOST = hwpr-vip2)(PORT = 1521))
(LOAD_BALANCE = yes)
(CONNECT_DATA =
(SERVER = SHARED) <<<<< this is my concern
(SERVICE_NAME = hwpr)
while documentation says that for dataguard dedicated server is required. so what changes do i need to do. Is it only required to changed the tnsnames.ora from shared to dedicated or any other init parameter is also required to be changed.Yes you must change in tnsnames.ora file for primary and standby side, together.

File Sharing Server Connection Gone

I am the designated tech person in my office. We just switched our ISP to Verizon FIOS from a DSL line. No one in the office is able to connect to the server remotely anymore. The addresses in the connect box are the same. It works at the office but not away from the office. Where do I begin to try to solve this problem?

Sorry, but Mark's solution isn't going to help here.
No one in the office is able to connect to the server remotely anymore
In what way are you trying to 'connect to the server'? Are you talking web service? VPN? file service? mail? something else?
When you changed from DSL to FiOS your public IP address changed. Did you change your public DNS records to reflect the new address? If not, external users are going to trying to connect to the old DNS address and not the new FiOS one. Even if you have changed it, DNS can sometimes take hours to propagate across the internet.
In addition to setting the DNS to point to the new address, you'll likely also need to configure port forwarding on the Verizon router to permit the protocol(s) you want to allow into your network. By default, most routers block all incoming traffic.
Beyond that, there isn't a lot of detail here to go on. If the above doesn't fix it you'll need to post more detail, including the domain name so that others can check the DNS resolution from an external perspective.

Shared Server Connection Problem On Rac

Hii All
I configured dispatcher parameter in Rac environment as
"alter system set dispatchers='(address=(protocol=tcp)(host=node1-vip.domain.com))(dispatchers=10) (session=75)' scope=both sid='RAC1';
but when I run lsnrctl services I see vip ip address instead of node1-vip.domain.com so I have connection problems because Client trying to access to server via internet through Nat ip address and listener replies requests vip ip address so client can not connect the server.
I can acces to server on DEDICATED connection.
Have you idea ?
Best Regards
GI 11.2.0.2 PSU4
RDBMS 11.2.0.1
OS AIX 6.1

EB wrote:
I did exactly what document says.Parameters are
on NODE1
dispatchers (address=(protocol=tcp)(host=node1-vip.domain.com))(dispatchers=10) (session=75)
local_listener (DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=node1-vip.domain.com)(PORT=1521)))
on NODE2
dispatchers (address=(protocol=tcp)(host=node2-vip.domain.com))(dispatchers=10) (session=75)
local_listener (DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=node2-vip.domain.com)(PORT=1521)))
In document lsnrctl ouput shows host=node-vip But I cant see nor node1-vip.domain.com neither node2.domain.com just see node vip address That does not really matter - as the hostname is an alias for an IP address and as long as the hostname resolves to the correct IP address.
The issue (as I mentioned above) is that the external client needs to resolve these names to the NAT addresses. So what happens if you ping node1-vip.domain.com and node1-vip from the client? What happens when you telnet on the client to port 1521 and hosts node1-vip.domain.com or node1-vip ?
If this works and the client's Oracle connection does not, enable SQL*Net tracing on the client and look in the trace file for failed calls.
Also keep in mind that you would (by default) only have port 1521 NAT'ed. So should the client be redirected for a connection using a different port, it is unlikely that this port is NAT'ed - unless you're basically blindly NAT'ing all ports which would be unusual and risky.

Oracle shared server default connection

We are currently trying to use shared server on an Oracle 11.1.0.7 standard edition database.
We don't have any problem regarding parameters or performance yet. We can connect either with dedicated or shared connection.
Our problem or issue is with tnsnames.ora.
trdb =
(DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = X.X.X.X)(PORT = 1521))
(CONNECT_DATA =
(SID = orcl)
We do not specify if this connection is shared neither dedicated. Connection defaults to dedicated and we would like to force that users connect to a shared server connection.
It would be really usefull to avoid having to go client by client on remote sites. We do no have any centralized management tool to change the file (not on remote sites).
We could, of course make the application to distribute a new file, but since every client is unique, it could be risky.

Try to use SERVICE_NAME instead of SID in tnsnames.ora and make sure this service is mapped to a dispatcher in database init. file.
Example with 11.2.0.1:
1. DISPATCHERS parameter
SQL> show parameter dispatchers
NAME                                 TYPE        VALUE
dispatchers                          string      (PROTOCOL=TCP) (SERVICE=DB112XDB)
max_dispatchers                      integer2. TNSNAMES.ORA:
$cat tnsnames.ora
DB112 =
(DESCRIPTION =
   (ADDRESS_LIST =
     (ADDRESS = (PROTOCOL = TCP)(HOST = lx01.localdomain)(PORT = 1521))
(CONNECT_DATA =
   (SERVICE_NAME = DB112XDB)
)3. Test with SQL*Plus:
sqlplus system/xxx@DB112 @tss
SQL*Plus: Release 11.2.0.1.0 Production on Mon Feb 15 21:37:35 2010
Copyright (c) 1982, 2009, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
SQL> select username, program, server, service_name
2 from v$session
3 where server<> 'DEDICATED';
USERNAME                       PROGRAM
SERVER    SERVICE_NAME
SYSTEM                         [email protected] (TNS V1-V3)
SHARED    DB112XDB

When we go for shared Server environment?

When we go for shared Server environment from Dedicated server mode?
When we have to choose thi shared Server mode?
Which is the optimized way?

> When we go for shared Server environment from Dedicated server mode?
You do not. It is not one or the other - it is using both correctly. You want shared server sessions to service applications (any, from web/app servers to flat clients) that are OLTP in nature. They fire off short-and-sweet SQLs that takes a second or three to execute.
A shared server pool of a few processes can service a very large number of clients.
You want to use dedicated servers to service OLAP type clients. They fire off complex SQLs that can tie up the server processes for several minutes at a time.
And that in a nutshell is how to apply the two. It is not Shared Servers versus Dedicated Server. It is about using The Right Tool For The Job. Nothing more and nothing less.
As for Windows, I will not really bother quickly with shared server connections. On Windows both shared and dedicated servers runs as threads in the main Oracle executable process image.
There is thus very little resource saving by reducing the number of threads as the footprint of a thread is tiny in comparison to a brand new process. The amount of resources saved by a reducing the number of dedicated server threads is not significant. If anything, Oracle on Windows has shown to scale better than Oracle on Linux in this regard. (refer to [url http://www.perftuning.com/pdf/Comparison_Oracle_Windows_Linux.pdf]A Comparison of Oracle Database 10gR2 Real Application Cluster Performance on Microsoft Windows 2003 Server Enterprise Edition x64 and Red Hat Enterprise Linux x86_64 from the Performance Tuning Corporation).
And this is exactly the opposite of how Oracle behaves on Unix. Each server process is a physical kernel process. This means that a servicing a 1000 concurrent sessions with a 1000 dedicated server processes, each consuming memory and resources, are expensive. Conversely, supporting a 1000 concurrent sessions with a 100 shared server processes is (almost) 90% cheaper.
This makes Shared Server a desirable option to use to scale OLTP sessions on Unix-based systems (or any platform where Oracle does not use multi-threading but multi-processing).
PS. As the Linux kernel support Posix threads (see http://en.wikipedia.org/wiki/Native_POSIX_Thread_Library), it begs the question as to when Oracle is going to support multi-threading on Linux instead of multi-processing.. or at least give us the option to choose.

Need to create a Database in Shared Serve Mode

Hi,
Please help me in Creating a Manual Database in Shared Server Mode. (I am a Student and It is a Learning Process).
I am able to Create Database (Without DBCA) in Dedicated Mode and I have no doubts in that.
What are the parameters i need to specify
Please post me Helpful Links

Poorna Prakash wrote:
Hi,
Please help me in Creating a Manual Database in Shared Server Mode. (I am a Student and It is a Learning Process).
I am able to Create Database (Without DBCA) in Dedicated Mode and I have no doubts in that.
What are the parameters i need to specify
Please post me Helpful LinksYOu need to understand that ... as far as the database is concerned ... it's not an either/or situation between dedicated and shared server. Setting shared server parameter like DISPATCHERS simply allows the database to handle shared server connections. But it is up to the client to specify which method it wants, and the database will always allow dedicated server connections.

Can we stop shared server from client m/c

Hi all,
Can we stop Oracle Shared and Dedicated server from Client Machine if i am connecting through SYSDBA.
Thanks
Vipin

> Can we stop Oracle Shared and Dedicated server from Client Machine if i am
connecting through SYSDBA.
Yes. No.
Yes, you can stop shared server. Simply decrease the shared server pool to zero. (see below for details)
No, you cannot stop a dedicated server as "The Thing" that creates dedicated server connections is the Listener. So you will need to stop that.
# stop shared server:
SQL> show parameter shared_servers
NAME TYPE VALUE
max_shared_servers integer 20
shared_servers integer 10
SQL> alter system set shared_servers=0 scope=memory;
System altered.
# now attempt a shared server connection
/home/billy> sqlplus scott/tiger"(DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL=TCP)(HOST=dev)(PORT=1521))) (CONNECT_DATA = (SID=dev) (SERVER=shared)))"
SQL*Plus: Release 10.2.0.1.0 - Production on Wed Sep 5 12:21:06 2007
Copyright (c) 1982, 2005, Oracle. All rights reserved.
ERROR:
ORA-12519: TNS:no appropriate service handler found
# start the shared server (in the SYSDBA session)
SQL> alter system set shared_servers=10 scope=memory;
System altered.
# now attempt a shared server connection
/home/billy> sqlplus scott/tiger@"(DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL=TCP)(HOST=dev)(PORT=1521))) (CONNECT_DATA = (SID=dev) (SERVER=shared)))"
SQL*Plus: Release 10.2.0.1.0 - Production on Wed Sep 5 12:21:17 2007
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - 64bit Production
With the Partitioning and Data Mining options
SQL>

Sutdown of a Database in Shared Server Modus

Hi,
I have set up today a database called "db03" in Shared Server Mode. After the installation everything looked fine beside that there was no entry in the listener.ora file for the Database. Anyways I added the entry to the listener.ora and was able to connect to it via the command
sqlplus "sys@db03 as sysdba".
But when I tried to shut it down it gave me the error message
ORA-00106: cannot startup/shutdown database when connected to a dispatcher
back.
So I have checked in several forums and someone said the solution would be to connect to the Database via dedicated connection and there for a entry in the tnsnames.ora file must be added.
(server=dedicated)
I added the line to connection descriptor and if I connect back to the database it really works and I am able to shutdown the database.
But is that really the best and Oracle recommended what to shutdown a Database running in shared server mode ????
Thanks Marcus

There is a note in the administrator's guide that you have to have a dedicated connection to be able to shut down the database...
http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96521/start.htm#7871
When a database is running in shared server mode, that just means that connections can be made to a shared server, not that all connections should connect to a shared server. When you are doing certain types of tasks, such as reporting, you are frequently better off requesting a dedicated connection. When you are shutting down the database, you have to request a dedicated session.
If you expect some of the sessions started from a particular machine to need dedicated connections and other sessions to require shared server connections, there are options other than modifying the TNS entry, but 99 times out of 100, anyone who will be shutting down a database will always want a dedicated connection.
Justin
Distributed Database Consulting, Inc.
http://www.ddbcinc.com/askDDBC

Question about Oracle Shared Server Performance

Is it true that the performance of the Oracle Shared Server on Windows plataformns, like 2003 server is poor. ?
And so that, I cant see any advantages to change its configuraton, on a 200 users configuration, where I can have at most 2.000 session.
Tks for help and some tips if you guys have them.
Fernando

Hi Fernando,
Is it true that the performance of the Oracle Shared Server on Windows plataformns, like 2003 server is poor. ? In general (not just Windows), shared servers (the MTS) should only be used if you have an acute RAM shortage.
Tom Kytes notes:
http://asktom.oracle.com/pls/ask/f?p=4950:8:::::F4950_P8_DISPLAYID:5269794407347
"Unless you have a real reason to use MTS -- don't."
"a shared server connection is by design "slower" than a dedicated server (more stuff goes on, more complex) it is most likely only getting in the way."
Also, remember that you can use AWE to take the data buffer above the line and free-up more low-memory RAM for connections. Here are my notes:
http://www.dba-oracle.com/oracle_tips_ram_waste.htm
http://www.dba-oracle.com/t_mts_multithreaded_servers_shared.htm
My experience concurs that Oracle shared servers should not be used without a compelling reasons (i.e. super high connect/disconnect rates on an instance with limited resources) and that the vast majority of Oracle databases will run more efficiently without shared servers.
Dedicated server connects are far faster than multi-threaded server connections, and 64-bit Oracle combined with the low cost of RAM has driven-down the rare cases where shared servers are justified.
Hope this helps. . .
Donald K. Burleson
Oracle Press author

Modify Database Shared/Dedicated Connections

Newbie question - we're running Grid Control 10.2.0.4 on RHEL 4. I have quite a few databases on other servers configured via the Grid Control GUI. Recently we discovered Grid Control was connecting to these databases via a SHARED Oracle network connection, and I would like to change this to a DEDICATED one. However, none of these databases are listed in any of the .../network/admin/tnsnames.ora files, so I'm guessing there is somewhere else to configure this in Grid Control?
I've looked on this forum and searched through the Grid Control manuals, but for the life of me I can't find where/how to configure this, so I'm guessing that I'm probably looking with/for incorrect terminology. I'm okay with reading up on how to do this, but am just wondering if someone can point me in the right direction of where to read on this? Thanks in advance for any input!

Take a look at Metalink Doc ID 757339.1 "How to : Configure Grid Control Agent to Use Dedicated Server Processes".
The agent will automatically make use of shared server connections, if the database is running in the shared server mode. But it seems you can edite the targets.xml file from the agent side edit to use dedicated.

Dedicated Server Process or Shared Server Process

Hi,
I am little confused to justify the number of users that may be best to use dedicated server process or shared server process.
Kindly advice.

In addition, make sure you account for administrative issues. It's a lot more challenging to trace applications using shared server connections. Shared server configurations also tend to introduce a variety of gotchas into a DBA's world-- at a minimum, most articles you find on the internet tend to ignore any shared server specific issues. That's one of the reasons that I tend to be of the opinion that if you have to ask, you probably don't need to enable shared server.
Justin

Shared server connections.

Similar Messages

Maybe you are looking for