File Server Example

Input Data

• are gathered from file server statistics.
• contain attributes: date, time spent in cpu, idle, and user states, and disk activities.

The input file looks like:

2 -2140595955 782593880(0/6/0.58)(0/17/1.48)(82/100/97.93)[0/205/7.3][0/8/0.18][0/8/0.35][0/8/0.22][0/8/0.18][0/8/0.15]{0/205/8.38}
2 -2140595955 782593941(0/3/0.3)(0/19/1.13)(81/100/98.57)[0/67/3][0/0/0][0/4/0.07][0/4/0.08][0/0/0][0/0/0]{0/67/3.15}
...

Problem

Visualization

The visualization is created as follows:

1. Define the two top views for first file server. In the first view, map date onto X axis, and idle time to Y. In the second view, map date onto X axis, and disk activity to Y axis. Map high system activity to red.
2. Define the bottom two views the same as the top two, but for a different sensor.
3. Link the X axes of all the views.
4. Navigate the views by scrolling or zooming.

Observations

1. This example illustrates the ability of DEVise to handle large amounts of data. About 6 MB of memory buffer is used to visualize 18 MB of files.
2. Cycle in the data: low idle and high disk activity is observed every night after midnight, during file backup.
3. Anomaly observed: The first server contains periods of high system time, but the second file server does not.