The 5000 clients hopefully do not all do a "TIME IS 00:00:00" message or
some kind of coordinated event with a signal coming from a common
external source (CP), do they? Something like that could overrun a lot
of buffers.
Jim
dave wrote:
Hi, Gary.
Well, there is no such thing as a free lunch, so
establishing *large* numbers of IUCV connections between
virtual machines does cost something. Control blocks must be
allocated, must be managed by CP, interrupts fielded, etc.
Off of the top of my head, I don't know how much storage
these control blocks take, but I would suspect that with CP
now being 64-bit, the amount of storage taken would not be a
significant issue.
Even if the amount of traffic between the clients and the VM
server is slight; the *timing* of the traffic might be a
concern.....5000 clients all sending a short IUCV message at
the same time to the server, might cause problems. The
server would have to have enough resources available to
process all of the traffic in an acceptable amount of
time....
Good luck.
----- Original Message -----
From: "Gary M. Dennis" <[EMAIL PROTECTED]>
To: IBMVM@LISTSERV.UARK.EDU
Subject: IUCV - What's wrong with this picture?
Date: Mon, 25 Aug 2008 12:23:49 -0500
Assumptions:
0. A VM server machine
1. A cluster of client virtual machines (possibly
thousands)
2. n buffers are allocated for each client virtual machine
3. Each buffer contains table elements that require
(a) Element ageing
(b) Element deletion when invalidated by:
1. lack of use
2. client machine request
(c) Compression as buffer fragmentation occurs
4. Each client virtual machine in the cluster is connected
via IUCV to the server virtual machine.
5. IUCV traffic between the server machine and client
machine is extremely low volume. Initial call,
termination call, intermittent statistics call.
6. After the initial call, the server virtual machine will
maintain the buffer table entries in each client virtual
machine without additional IUCV interaction.
Now the questions:
1. Does IUCV infrastructure overhead specifically
associated with number of connections become prohibitive
at some well known point?
2. Has anyone had experience with an application having a
high IUCV connection count like this? If so, what was that
experience?
Again, the traffic incidence per connection is very low
but the number of connections is potentially very high.
Thanks
--. .- .-. -.--
Gary Dennis
--
Jim Bohnsack
Cornell University
(972) 596-6377 home/office
(972) 342-5823 cell
[EMAIL PROTECTED]
