report work

report/Claudio_Maggioni_report.tex

@@ -638,24 +638,58 @@ number of termination events per task, broke down by task termination. In
 addition, the table shows the mean number of \texttt{EVICT}, \texttt{FAIL},
 \texttt{FINISH}, and \texttt{KILL} for each task event termination.
 
-\textbf{Observations}:
+The first observation we make is that the mean number of events per
+\texttt{EVICT}ed and \texttt{FAIL}ed tasks increased more than 5-fold (namely
+from 2.372 to 78.710 and from 3.130 to 24.962 respectively). Also observing the
+95-th percentile we can say that the number of events per task has generally
+increased overall.
 
-\begin{itemize}
-\item
-  The mean number of events per task is an order of magnitude higher
-  than in the 2011 traces
-\item
-  Generally speaking, the event type with higher mean is the termination
-  event for the task
-\item
-  The \# evts mean is higher than the sum of all other event type means,
-  since it appears there are a lot more non-termination events in the
-  2019 traces.
-\end{itemize}
+As observed in 2011, 2019 Borg tasks have all a multitude of events with
+different types, with \texttt{FINISH}ed tasks experiencing almost always
+\texttt{FINISH} events and unsuccessful tasks and the same observation holding
+for \texttt{KILL}ed tasks and their \texttt{KILL} events. Differently from the
+2011 data, \texttt{EVICT}ed tasks seem to experience an high number of
+\texttt{KILL} events as well (25.795 on average per task, over 78.710 overall
+events on average). A similar phenomena can be observed with \texttt{KILL}ed
+jobs and their \texttt{EVICT} events (1.876 on average per task with a 8.763
+event overall average).
 
-\subsubsection{Conditional Probability of Task Success}
+Considering cluster-by-cluster behaviour in the 2019 traces (as reported in
+figure~\ref{fig:tableIII-csts}) the general observations still hold for each
+cluster, albeit with event count averages having different magnitudes. Notably,
+cluster E registers the highest per-event average, with \texttt{FAIL}ed tasks
+experiencing 111.471 \texttt{FAIL} events out of \texttt{112.384}.
+
+\subsection{Conditional Probability of Task Success}
 \input{figures/figure_5}
 
+In this analysis we measure the conditional probability of task success given a
+number of specific unsuccessful (i.e. \texttt{EVICT}, \texttt{FAIL} and
+\texttt{KILL}) events. This analysis was conducted to better understand how a
+given number of unsuccessful events could affect the termination of the task it
+belongs to.
+
+Conditional probabilities of each unsuccessful event type are shown in the form
+of a plot in figure~\ref{fig:figureV}, comparing the 2011 traces with the
+overall data from the 2019 ones, and in figure~\ref{fig:figureV-csts}, as a
+cluster-by-cluster breakdown of the same data for the 2019 traces.
+
+In figure~\ref{fig:figureV} the 2011 and 2019 plots differ in their x-axis:
+for 2011 data conditional probabilities are computed for a maximum event coun
+t of 30, while for 2019 data are computed for up to 50 events of a specific
+kind. Nevertheless, another quite striking difference between the two plots can
+be seen: while 2011 data has relatively smooth decreasing curves for all event
+types, the curves in the 2019 data almost immediately plateau with no
+significant change easily observed after 5 events of any kind.
+
+The presence of even one \texttt{KILL} event almost surely causes the
+corresponding task to terminate in an unsuccessful way: a task with no
+\texttt{KILL} events has 97.16\% probability of success, but tasks with 1 to 5
+\texttt{KILL} events have 0.02\%, 0.20\%, 0.44\%, 0.04\%, and
+0.07\% probabilities of success respectively. The same effect can be observed,
+albeit in a less drastic fashion, for the \texttt{EVICT} and \texttt{FAIL}
+curves. The \texttt{EVICT} curve has for 0 to 5
+
 Refer to figure \ref{fig:figureV}.
 
 \textbf{Observations}: