






UC4 - Iteration 2
UC4: User visualizes traffic flow information.
Primary Actor: Peer-to-peer Researcher / ODIN Developer.
Secondary Actor: Students, peer reviewers of ODIN research.
Stakeholders and Interests:
ODIN Developer:
Wants to inspect the level of communication amongst ODIN peers (either in general, or for specific peer-pairs) for debugging and performance tuning.
All Actors:
Want an indication of the level of communication amongst ODIN peers. Want to be able to quickly identify unusually popular and unpopular communication links.
Preconditions:
- The network viewer is already up and running, and an ONA (ODIN Network Activity) file has been loaded.
- Playback of the activity in the file has started (i.e. currently either playing or paused) and messages are being sent throughout the network.
Success Guarantee (Postconditions):
The color and transparency level of each visible link will correctly indicate the amount of activity1 on the link. A link will not be visible if and only if it is not a display candidate, or its activity falls under the threshold chosen by the user.
1. How the activity level will be quantified and the precision to which it will be indicated visually are unknown at this time. See open issues below.
Main Success Scenario
- If the user wants to change the activity level threshold for displayed links, execute extension UC4.1 Change Activity Level Threshold.
- If the user wants to change the activity transparency level for displayed links, execute extension UC4.2 Change Activity Transparency Level.
- The user may choose to do neither of these and instead just watch the animation using the initial settings (threshold of zero, transparency level of zero percent).
Extensions (Alternative Flows):
None for top level use case, see extensions UC4.1, UC4.2
Special Requirements:
NONE
Technology and Data Variation List:
Some users may be using black and white monitors or otherwise targetting displays of the graph in black and white (e.g. a screen capture for inclusion in a white paper). See Open Issues.
Frequency of Occurrence:
As often as the user chooses to change these levels. Could be adjusted several times rapidly (more than once a second) and then not adjusted for several minutes ala a volume setting.
Open Issues:
- We may want to support black and white display of activity levels. If the customer finds this highly desirable, we will need to experiment with either using grayscale or using line width and transparency instead of line color and transparency.
Are other open issues are related to usability and will likely require trial-and-error or usability testing with our customer.
- We are not sure yet whether to make the color and transparency of a communication link:
- a gradient
- one of only a few colors, which sacrifices precision but may make comparision and identification (possibly via an on-screen legend) of the message activity level easier.
- We are not sure yet how to compute our communication level metric.
- Should we count bytes sent or the number of messages sent, regardless of size?
- Should we only examine activity within the last second? the last 5 seconds? the last 60 seconds?
- Should we allow the user to change how the communication level metric is computed during playback? Or would that be overloading the user with features they probably won't use?
Link to this Page