Chapter 4 - DSpace at Waseda University

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Chapter 4
In Figure 4.10, the pseudo code shows the relation between each layer. First, in the
detection layer, KAS checks whether the kernel problem occurred or not. Although it was e
xplained in Figure 4.9, if it happened, the detection_problem() function saves information
of the location and the number of times errors occurred. Next, in the separation layer, the
separation_data() function separates the events of from the whole event log by using
position_data (line information). After that, the save_separation_data() function saves the
information. Finally, in the analysis layer, the analysis() function analyzes the information,
and the analysis_save_data() function unifies and save the data analyzed. A problem solution
can be more easily and effectively found by analyzing the cause of the problem using the
results from the three steps defined above.
4.3.1 Important Function and Parameter
In this section we will be explaining about various parameter functions used by KAS.
We will introduce important parameters among parameters declared by KAS. First, the
most important parameter is event_name. The variable is read before analyzing by KAS, it
decides what events will KAS analyze by reading event_name variable. Next we have the
event_time variable. This parameter is a variable that saves the performance time of every
event. By looking at event_time, one decides how much time each event used. After that,
there is the event_description variable. This variable is a variable that saves information of
each event except for event name and time information (PID, syscall_id, CPU_id, etc.).