Holt Winters

The following graph shows the CPU time taken by the JVM of a pool of collectors under normal circumstances (graph generated by Arecibo, see http://github.com/ning/Arecibo):

As one can see, we can distinguish two classes of servers:

• Collectors with usage mostly constant over the specified 6 hours
• Collectors with highly noisy CPU process time, with a decreasing trend over time

Let’s focus on the later and pick one of the collectors (referred to as collector1) from the pool.
Here is the time series as plotted in R:

Under normal circumstances, the distribution follows a normal distribution as shown in the following QQ plot:

\[ X ~ N(-309626.2, 2.47496e+14) \]
\[ \mu = -309626.2 \]
\[ \sigma = 15732005 \]