Re: TNS on Sun Solaris

Greg Stark <greg-spare-1_at_mit.edu> writes:

> Frank van Bortel <f.van.bortel_at_vnl.nl> writes:
>
> > Sybrand Bakker wrote:
> >
> > > Hi Frank,
> > >
> > > Do you have any proof of that? My initial guess is the same as your
> > > recommendation but my recent experiments showed that using bequeath (a
> > > variant of IPC) tnsping was up to 8 times slower (around 1000 secs).
>
> Slower for initial connection or for executing queries? Is this running MTS?
> Do you have your listener doing pre-forked servers (I forget what Oracle calls
> them)?
>
> Bequeath == fork in Oracle-speak, I'm not sure from what operating system this
> comes though. So every bequeathed server means doing a fork and exec of Oracle
> and then setting up the shared memory and semaphores for the SGA. Once started
> then it uses IPC to communicate with the started process though.

The shared memory and semaphores are set up at database start up time, so that's done only once, not per connection.

The communication is done through Unix pipes.

The fork and exec are done every time, though.

I think that the bequeath term comes from VMS. Oracle originally was developed on that operating system.

>
> Whereas an IPC connection contacts the listener and obtains an existing
> already running server whether an already forked dedicated server or a shared
> MTS server.

In the standard configuration, a dedicated server is spawned every time the client contacts the listener. If the PRESPAWNED option is used, however, then an already existing server is used. The same is true if the MTS is being used.

>
> 1000 seconds is wayyyy long though. Under heavy load this server can start a
> dedicated server in a maximum of 900ms. Under less load it's like 10ms.
I totally agree.

>
> --
> greg

--

                                        Rick
                                        Rick Wessman
                                        Security and Directory Technologies
                                        Server Technologies
                                        Oracle Corporation
                                        rwessman_at_us.oracle.com

       The statements and opinions expressed here are my own and do not
             necessarily represent those of  Oracle Corporation.