Re: ye olde 1521

  • From: amit poddar <amit.poddar@xxxxxxxx>
  • To: hporas@xxxxxxxxxxx
  • Date: Fri, 04 Feb 2005 10:23:57 -0500

"

Just wondering if one of my strongly held untested assumptions is wrong. I 
always thought that when you connected to Oracle via the listener in dedicated 
server mode, you would come in via the listener port (i.e. 1521, 1526). The 
listener would then validate, spawn off a shadow oracleSID process using some 
arbitrary port, and the client would then be passed to this process with the 
listener butting out at that point. The client would then be connected to the 
database through that arbitrary port.

"

What you mention is true only for windows platform that also with Winsocks in 
play.

On Unix everything goes throug port 1521.

The listner forks a copy of itself, the child runs the oracle executable. Since 
the socket survives across a fork the child (i.e oracle executable/dedicated 
server process ) talks to the client via 1521 only.

amit


Henry Poras wrote:

>Just wondering if one of my strongly held untested assumptions is wrong. I 
>always thought that when you connected to Oracle via the listener in dedicated 
>server mode, you would come in via the listener port (i.e. 1521, 1526). The 
>listener would then validate, spawn off a shadow oracleSID process using some 
>arbitrary port, and the client would then be passed to this process with the 
>listener butting out at that point. The client would then be connected to the 
>database through that arbitrary port.
>Last week a developer and myself checked this out. He sniffed the coming and 
>going of packets, and everything used only port 1521. I looked at netstat (I 
>think the parameters were asp (RedHat AS3 OS) but I'm not  sure. That info is 
>at work but I'm not at the moment) and the only active Oracle ports were also 
>1521. Are other ports used? Is this dependent on load? I searched metalink and 
>found the question asked, but no answers were ever posted.
>
>Thanks.
>
>Henry
>
>
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>
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>

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