Semester Graphs
Fall 2009 (9/18/09 - 12/18/09, excluding weekends and student holidays) data is presented below, broken down by data point, or as a PDF here.
Login Breakdown
Because logins are provided on a per-weekly basis, this data set runs from 9/2/09 to 12/19/09 and does not exclude weekends or holidays.
This shows the breakdown of total Athena logins by machine type.
(click for larger version)
Occupancy Rate
A good metric of cluster use is the occupancy rate for any given cluster. Unfortunately, the average daily occupancy rate for any given cluster is skewed by the fact that the occupancy for most clusters is nearly 0 between the hours of midnight and 9:00am. If the occupancy rate is presented as a range between average daily high occupancy and average daily low occupancy, we get a much better representation of cluster usage.
The occupancy rate graph for Fall 2009 is presented here:
Graph | Notes |
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The extent of the vertical lines indicates the range from average daily low occupancy to average daily high occupancy. The horizontal lines indicate the overall average daily occupancy (which, as noted above, is skewed by the early morning hours). Clusters are arranged largest to smallest (L-R) |
As you can see, many of the clusters exceed 80% occupancy during the day. Some clusters, however, are underutilized and perhaps some workstations in those clusters could be replaced with small group workspaces.
Instances of Full Capacity
Another good metric of cluster use is the number of days in which a cluster has at least one occurrence (5 minutes) of full capacity (that is, all the workstations are occupied). This tell us the relative popularity of a cluster.
The instances of peak capacity for Fall 2009 is presented here:
Graph | Notes |
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Clusters are arranged largest to smallest (L-R) |
As you can see, 12-182 and 56-129 remain highly popular, as does E51-075, as it is the only cluster east of Ames St. Another interesting trend is that all the library clusters (Hayden, Rotch, Barker) experienced days with peak capacity, perhaps indicating the value of these clusters as quiet workspaces.
Data Sources
Login Reports
Starting in early 2005, we began collecting data on the number of logins Athena-wide. We capture both total logins and unique logins on a weekly basis. Unique logins are users who logged in at least once in the one-week period.
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Academic Year | File | Notes |
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2004-05 | Data begins 2/26/05 | |
2005-06 | Login breakdowns by type begin 3/18/06 | |
2006-07 | Starting 1/27/07, dialup logins are included in "other" | |
2007-08 | — | |
2008-09 | Data missing for 11/22, 11/29, 12/6, 12/13. |
Cluster Usage Data
Starting in 1992, usage data was collected Athena-wide. The larvnet server snapshots cview data on an hourly basis throughout the day, and then averages those snapshots to create the average number of machines free per day. The minimum and maximum total number of machines are also recorded. (The total number of machines can decrease if a machine breaks or is taken out of service).
Starting in December 1998, usage data was broken down by cluster.
NOTE: Due to various outages or migrations of the larvnet and syslog servers over the years, some portions of the raw data had duplicate entries – that is, entries for the same day and cluster. These duplicate entries were pruned. In some cases, it was clear which entry to prune, either because the entries were exact duplicates of each other, or because the values were clearly erroneous (for example, showing 0 total machines in a cluster). In other cases, a more subjective method was used. Regardless, each spreadsheet lists the pruned data so it can be reincorporated if necessary.
Each Excel file has two sheets in it – one containing the actual data, and another listing the duplicate entries that were pruned from the raw data.
Athena-Wide Usage Data |
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