That advice goes without saying...any effort to develop a sophisticated VM application demands a good monitor to help the developers tune that application to meet performance goals.
DJ ----- Original Message ----- From: Barton Robinson <[EMAIL PROTECTED]> To: IBMVM@LISTSERV.UARK.EDU Subject: Re: IUCV - What's wrong with this picture? Date: Mon, 25 Aug 2008 19:13:20 -0800 > Sounds like there is a need for decent performance > monitoring. > > > 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 > > > > > >
