RE: Oracle Heap memory usage by listener

From: Mark W. Farnham <>
Date: Thu, 11 Feb 2016 08:36:55 -0500
Message-ID: <01c601d164d1$46110cc0$d2332640$>

I don't know about them and with the service model this concern is answered, but the original reason MOSES and VLDB recommended a listener for each instance on a machine was so that remote attempts to connect to a given instance could be pre-empted with the minimum overhead by shutting off a given listener. Since each instance had its own listener, no inconvenience was experienced by users of any other instance. I believe the service model was introduced (at least in part) to address this concern.  

Furthermore, in the multi-threaded server model from before the thread, that too could be controlled distinctly for each instance more easily.  

Machines of the day did not contemplate such large numbers of instances running on a single machine. The useful limit there was easily less than 2 dozen and probably was closer to 10.  


PS: I think it is a hyperbolic to claim the listener model was replaced in 8 and more fair to report the service model was introduced in 8 and certainly is very stable now. (If you're playing with toys it doesn't much matter which you use. Production should be in service model by now, and I'm all ears for any exception to that line of thinking.)  

From: [] On Behalf Of Hans Forbrich
Sent: Wednesday, February 10, 2016 10:43 PM To:
Subject: Re: Oracle Heap memory usage by listener  

Just curious: That SID-listener model was used with Oracle 7 and was replaced by the Service model with Oracle 8. Aside from increased administration at the db, os and network levels (poking more holes into the firewall) what benefit to they see to having a listener for each instance?


On 10/02/2016 8:26 PM, Balwanth Bobilli wrote:

Oracle version :

Microsoft Windows server 2012

RAM: 1TB (680GB free memory while getting this error)  

One of our customer wants to run 80 SIDS and 80 listeners (each listener for each database).. After all listeners are running, we are seeing TNS-12531: TNS: cannot allocate memory. From Doc ID 1384337.1( 2793106930444
< 0444&id=1384337.1&_afrWindowMode=0&_adf.ctrl-state=qi0lglvuc_210> &id=1384337.1&_afrWindowMode=0&_adf.ctrl-state=qi0lglvuc_210)

We got to know that changing third argument of \HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\SubSystems\: will help us, Increasing this third value and check whether TNS error disappears. There is no optimum value, it depends from one system to another.  

However we are planning to increase it, I see that there is no optimum value for setting and maximum value is 8192.  

Current value is

C:\Windows\system32\csrss.exe ObjectDirectory=\Windows SharedSection=1024,20480,2048 Windows=On SubSystemType=Windows ServerDll=basesrv,1 ServerDll=winsrv:UserServerDllInitialization,3 ServerDll=sxssrv,4 ProfileControl=Off MaxRequestThreads=16  

We are planning to change it to 4096 Before proceeding further we want to know  

  1. how SharedSection is used for non-interactive processes running as Local System? If we keep it 4096 will that impact the performance?
  2. Any tools to monitor heap memory usage (sysads here tried installing dheapmon and livekd, which is unable to do so on windows sever 2012)
  3. Is there any other solution to work around on this?

Note: No traffic from application, just few connections.

Shared server configuration    

Received on Thu Feb 11 2016 - 14:36:55 CET

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