The last section illustrated how the Daily Project Details analysis can provide a summary of the state of a Project for a particular day. One issue with these server-side analyses is the requirement that you must log in to the server and run the analysis in order to see the results. It would be more usable if, instead of having to "poll" the server for useful data, the server could instead "alert" you when data of interest appears.
The Hackystat alert mechanism generates a single email to each user containing information about all of the alerts that were generated for that day. The email is only generated if at least one alert is triggered for the current day. When triggered, an alert generates both a textual summary of the alert, as well as an URL that would invoke a command at the server to generate more detailed information regarding the alert.
Figure 3.15, “ The Alert Page ” illustrates the Alert page for a user and two Alerts: Bad Data Received and Daily Project Summary.
The "Bad Data Received" alert sends you an email when sensor data is received by the server with your user key but is corrupted in some fashion. Receiving a Bad Data Alert usually means that the version of at least one of your sensors is incompatible with the server and you must download the up to date version. Less frequently, it indicates a bug in the sensor implementation that must be corrected by a developer. As the selector indicates, this alert is enabled for this user.
The Daily Project Summary alert enables you to receive an email message once a day with a summary of project data received during the previous day for any of your currently defined Projects. This alert is not triggered if none of your selected Projects generated any data for the given day. In this case, the user has specified that an alert email should be generated only if the Project "hacky2004-all" receives any data on the given day. Data received regarding any of the other defined Projects will not generate the email alert.
Figure 3.16, “ A daily email generated by the Alert mechanism ” illustrates an email that could be generated from the Alert mechanism.
This email shows a summary of the data gathered for the hacky2004-all Project on the previous day, and a link that will invoke the Daily Project Details command for the given day and Project. As described in Section Section 3.9, “An example Project-based analysis: Daily Project Details”, the Daily Project Details command provides drilldowns with more detailed information about the data gathered for this Project.
Hackystat alerts are implemented in terms of a "trigger", which indicate whether information about this alert should be included in the daily alert email. Some triggers, such as the Daily Project Details, check only to see whether data has been received. Other triggers might check for specific properties of the data.