Re: Oracle 8i (8.1.7) problem with a lot of simultaneous connections -> ORA-12541 No listener available

does the Oracle database server run on WIN2K server? and what kind license?

"Tomislav" <shaka_at_envox.hr> wrote in message news:<MRLN4495E1EDF_at_merlin.envox.hr>...
> I have a multithreaded application written in Windows 2k/C++ that uses OCI
> to
> access a remote Oracle 8i database. Both versions of Oracle are 8.1.7, on
> Client and Server side.
>
> I use a single OCIEnviroment handle for all threads and I initialize &
> destroy it only once with OCI_THREADED flag.
>
> Each of my threads opens a connection and executes an Select statement over
> and over again (infinitely - in this test case).
>
> When I start 16 threads at the same time, they wait a bit for opening the
> connection to the remote Oracle server (in the 100 Mbit LAN), after that
> they start
> executing simultaneously without any problems Select statements and fetching
> small resultsets.
>
> Different case is when I start like 32 threads. Then at database opening
> time some
> of them (like 6) produce "ORA-12541: no listener available" error message
> when trying to open database connection. When I try to open the connection
> again in those threads, it succeeds.
>
> When I start 64 threads, 27 of them produce "ORA-12541" and 15 of them
> produce "ORA-12541" even the second time they try to open connection as
> well. Third time they succeed and after that all of them (all 64 work at the
> same time).
>
> Is this a message of type "Network busy" or "Client busy" or whatever it
> means?
>
> Why isn't this explained better in documentation or signaled better through
> OCI return codes?
Received on Mon Jan 14 2002 - 22:20:47 CET