IDS Forum

Re: IDS 10.00 maximum concurrent sessions

Posted By: Art Kagel
Date: Tuesday, 23 March 2010, at 11:38 p.m.

In Response To: Re: IDS 10.00 maximum concurrent sessions (KRISHNAN BALA)

First, you CAN limit the number of concurrent shared memory connections.
Since the communications blocks that shared memory connections use and the
semaphores that protect them are allocated when IDS starts up, the number of
available connections via shared memory is fixed at startup by the NETTYPE
ipcshm setting. The limit is the product of the number of poll threads
configured and the number of connection slots per poll thread. So, for
example, in this configuration:

NETTYPE ipcshm,2,25,CPU

There are two poll threads (one in each of the first two CPU VPs) each of
which manages 25 shared memory slots for concurrent connections. It is the
network protocol connections which are unlimited as they can be, and are,
increased on the fly by the network poll threads. So while this
configuration:

NETTYPE tlitcp,2,100,NET
NETTYPE drda,2,100,NET

Allocates 2 poll threads for SQLI (Informix native communication protocol)
TCP/IP connections each with 100 connection slots, and 2 poll threads for
IBM's DRDA protocol TCP/IP connections each with 100 connection slots, if
10000 users were to suddenly connect to the IDS instance via either
protocol, the poll threads would simply allocate more internal memory slots.

As far as managing or counting the number of connections, you can:

SELECT COUNT(*)
FROM sysmaster:syssessions
WHERE NOT (username = 'informix' OR pid = 0);

The username and pid filter will keep you from counting the internal engine
sessions.

Art

Art S. Kagel
Advanced DataTools (www.advancedatatools.com)
IIUG Board of Directors (art@iiug.org)

See you at the 2010 IIUG Informix Conference
April 25-28, 2010
Overland Park (Kansas City), KS
www.iiug.org/conf

Disclaimer: Please keep in mind that my own opinions are my own opinions and
do not reflect on my employer, Advanced DataTools, the IIUG, nor any other
organization with which I am associated either explicitly, implicitly, or by
inference. Neither do those opinions reflect those of other individuals
affiliated with any entity with which I am affiliated nor those of the
entities themselves.

On Tue, Mar 23, 2010 at 11:20 PM, KRISHNAN BALA <keiyer@gmail.com> wrote:

> Hi Art,
>
> Thanks for your quick respose. We are using shared memory connections .
> Also
> noted that there is no limit for the concurrent sessions. My issue is i
> want
> to control the number of sessions, i.e. maximum number of concurrent
> sessions.
> Say for ex i dont want the maximum number of concurrent sessions to go
> above
> 50. Is there any method where in i can do a lookup in the sysmaster
> database
> and find out the numebr of current concurrent sessions. If yes then I can
> take
> it from there.
>
> Thanks once again...
>
> Bala
>
>
>
> *******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>

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Messages In This Thread

• IDS 10.00 maximum concurrent sessions
  KRISHNAN BALA -- Tuesday, 23 March 2010, at 1:28 a.m.
  • Re: IDS 10.00 maximum concurrent sessions
    Art Kagel -- Tuesday, 23 March 2010, at 6:35 a.m.
  • Re: IDS 10.00 maximum concurrent sessions
    KRISHNAN BALA -- Tuesday, 23 March 2010, at 11:20 p.m.
    • Re: IDS 10.00 maximum concurrent sessions
      Art Kagel -- Tuesday, 23 March 2010, at 11:38 p.m.
      • Re: IDS 10.00 maximum concurrent sessions
        KRISHNAN BALA -- Wednesday, 24 March 2010, at 1:25 a.m.
        • Re: IDS 10.00 maximum concurrent sessions
          KRISHNAN BALA -- Friday, 26 March 2010, at 3:22 a.m.
          • Re: IDS 10.00 maximum concurrent sessions
            Art Kagel -- Friday, 26 March 2010, at 7:04 a.m.
            • Re: IDS 10.00 maximum concurrent sessions
              KRISHNAN BALA -- Friday, 26 March 2010, at 9:07 a.m.
          • Re: IDS 10.00 maximum concurrent sessions
            Richard Snoke -- Friday, 26 March 2010, at 10:30 a.m.
            • Re: IDS 10.00 maximum concurrent sessions
              KRISHNAN BALA -- Friday, 26 March 2010, at 10:57 p.m.

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