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Re: Shared_server_sessions parameter and dispatcher sessions attribute

From: Sybrand Bakker <gooiditweg_at_sybrandb.demon.nl>
Date: Tue, 10 Jun 2003 22:46:39 +0200
Message-ID: <angcevclvbkr60emj33n5eai4665nclako@4ax.com>


On Tue, 10 Jun 2003 18:08:31 GMT, Peter <peter_at_nomorenewsspammin.ca> wrote:

>On Tue, 10 Jun 2003 05:01:00 GMT, Peter <peter_at_nomorenewsspammin.ca>
>wrote:
>
>>On Tue, 10 Jun 2003 06:38:15 +0200, Sybrand Bakker
>><gooiditweg_at_sybrandb.demon.nl> wrote:
>>
>>>On Tue, 10 Jun 2003 03:33:33 GMT, Peter <peter_at_nomorenewsspammin.ca>
>>>wrote:
>>>
>>>>On Tue, 10 Jun 2003 00:38:43 +0200, "Sybrand Bakker"
>>>><postbus_at_sybrandb.demon.nl> wrote:
>>>>
>>>>>
>>>>>"Peter" <peter_at_nomorenewsspammin.ca> wrote in message
>>>>>news:7nr9evgid2hlrgcs432bd74ulbqtmud238_at_4ax.com...
>>>>>> I have this dispatcher parameter that I like to set up.
>>>>>> What is the difference between the dispatcher connections attribute
>>>>>> and the sessions attribute? Are the sessions referring to user
>>>>>> sessions? Are the connections actual connections to the instance?
>>>>>>
>>>>>>
>>>>>dispatchers="(protocol=tcp)(dispatchers=2)(pool=on)(connections=100)(session
>>>>>s=200)"
>>>>>>
>>>>>>
>>>>>> Also, what is the difference between the SHARED_SERVER_SESSIONS
>>>>>> initialization parameter and the dispatcher sessions attribute?
>>>>>>
>>>>>> Thanks
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>Reading the manual for you (and I will do this *ONCE ONLY*)
>>>>>
>>>>>Your 200 sessions are being dealt with by 100 connections.
>>>>>The essence of pooling is that connections will be shared by multiple
>>>>>sessions.
>>>>>
>>>>> Connection pooling is defined as
>>>>>
>>>>>A resource utilization and user scalability feature that enables you to
>>>>>maximize the number of sessions over a limited number of protocol
>>>>>connections to a shared server.
>>>>>
>>>>>The shared server sessions parameter according to the reference manual is
>>>>>the maximum number of shared servers you can have on the server.
>>>>>As a *client* session can be and will be dealt with by *multiple* shared
>>>>>servers, there is no relationship, other than on a busy database you can run
>>>>>out of shared servers on the servers.
>>>>>
>>>>>Question: did you look this up in the reference manual? I can find it with 1
>>>>>or 2 clicks. It doesn't look like you want clarification, you want others to
>>>>>do something you could have looked up yourself.
>>>>
>>>>I looked it up in the manual before, if shared server sessions
>>>>parameter is the maximum number of shared servers, then what is
>>>>parameter SHARED_SERVERS ?
>>>>
>>>>From the manual:
>>>>SHARED_SERVERS specifies the number of server processes that you want
>>>>to create when an instance is started up.
>>>>
>>>>They have quite similar descriptions and this causes even more
>>>>questions.
>>>>
>>>>Thanks
>>>>
>>>Look at what it says: the shared servers parameter determine how many
>>>server processes you will get started *at startup*. After that the
>>>number of shared servers will increase on demand as needed, until
>>>shared_server_sessions is reached. That is all what it is.
>>>And, IIRC, this concept is explained in the Oracle Database
>>>Administrator manual.
>>>
>>>
>>
>
>It seems that shared_server_sessions and MAX_SHARED_SERVERS are very
>similar.
>
>If SHARED_SERVERS specifies the number of server processes that you
>want to create when an instance is started up, and
>shared_server_sessions is the maximum that it is allowed to reach;
>then what is MAX_SHARED_SERVERS?
>
>From the manual, MAX_SHARED_SERVERS specifies the maximum number of
>shared server processes allowed to be running simultaneously.
>
>Thanks
>

The architecture has changed from 8i to 9i. I'm on 8i. Usually there is a chapter on MTS in the Oracle Administrators manual and a chapter on MTS in the NET administrators manual. They usually explain it nicely.
My gut feeling is that shared_server_sessions have to do with the maximum number of sessions allowed during connection pooling. As you don't have MTS working as of yet, I would recommend being somewhat less ambitious and get it working without connection pooling first, and work from there. MAX_SHARED_SERVERS is definitely used in a non-pooled environment.

Sybrand Bakker, Senior Oracle DBA

To reply remove -verwijderdit from my e-mail address Received on Tue Jun 10 2003 - 15:46:39 CDT

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