%ex2.2

\begin{enumerate}[label=(\alph*)]
	\item
		Yes. Some words (e.g. "I", "a", "are",..) will occur very often, the
		reducers handling that key will take very long to process all values.
		Other reducers handling less frequently used words will be finished in
		less time by far.
	\item
		With less reducers the total time will go up, but the skew will be
		less, as the long lists are more likely to be moved to a reducer which
		had short lists before (as that one will be finished sooner)
		With 10000 reducers the skew will go up, as a few of those reducers
		will have to handle very long lists, while the others will finish early
		and idle. This is still assuming that we don't have a combiner.
	\item
		It will be much less skew than if we don't use a combiner. A lot of
		words appear lots of times on a page, so pre-processing them with a
		combiner will reduce the number of values for the reducers
		significantly, and this also will reduce communication cost.
	\item
		Communication cost will increase, as the reducer size can be set to
		lower values. This will also reduce the skew in the times taken by the
		reducers.
		Replication rate will stay the same, as this is determined by mapped
		values divided by inputs (which is about 2500 for an average webpage)
		Reducer size can go down, in order to reduce reducer runtime skew.
\end{enumerate}
