Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!melpar!toppin
From: toppin@melpar.UUCP (Doug Toppin)
Newsgroups: comp.software-eng
Subject: Visual Representation of IPC/Network Message Flows? (long)
Keywords: software design, communication
Message-ID: <207@melpar.UUCP>
Date: 19 Oct 90 15:01:58 GMT
Organization: E-Systems, Melpar Division, Falls Church, VA
Lines: 63

I have for years never been able to find or come up with a
good technique for describing IPC and network message
flows visually/graphically.
This has become even more acute as we have entered the TCP world
and have to indicate long duration and temporary connections
with the message traffic that crosses them.
In our systems our software exchanges numerous messages locally and with
remote processors, each message uniquely identified by a message number prefix.
For example:
    struct
    {
        long msgid;     /* message identifier */
        long value1;    /* data */
        int  value2;    /* data */
    } M1000;            /* message number 1000 */

Our systems consist of numerous 'server' processors and a number
of operator workstations.
An approach that we generally use is a simple textual representation
like this:

STEP  ACTION   P1     P2     P3     P3     P4     P5     P6     P7
01     cmd      O                    D
02     cmd      D                    O
03     cmd      O                                  D

Where:
    STEP   - an action in the flow
    ACTION -  message ID transferred
    Pn     - processor list
    O      - action originator
    D      - action destination

A drawback of this is that this shows only the network
message traffic, requiring a second, similar set of pictures for the
intraprocessor message flows.
The intraprocessor flows have to indicate message queue, signal,
and shared memory communications.

I am interested in any visual representation approaches that
seem to work well for you.
What I would like appear in the picture would be:
    1) server process and processor
    2) client process and processor
    3) connections and IPC message queue traffic
    4) message IDs and action description in the transfers
    5) if the path is a socket and whether a single or session connection
       (meaning the path is bidirectional)
I am interested in either commercial products or just pencil
and paper approaches.
The approach must be understandable to software designers, implementers,
and useful for customer design review presentations.
This means it has to fit on a screen or a viewgraph machine.
It is particularly important to be able to pick up the pictures
a year later during integration and be able to understand them.
I would appreciate hearing about whatever you find useful.
Please post or drop me a line and I will post worthwhile responses.
If you want to send an example picture via Fax I will send you our number.
We have Sun equipment so images can be sent to me also.

thanks
Doug Toppin
uunet!melpar!toppin