Home Work 4
3)
Advantages of Heron over Storm:
Heron has several major upgrades as compared to Storm, the most important of them all are better traffic congestion handling and easy debugging. Heron has a back pressure mechanism that dynamically adjusts the rate of data flow in a topology during execution, without compromising data accuracy. This is particularly useful under traffic spikes and pipeline congestions.
As for debugging, since every task in Heron runs in process-level isolation, this makes it easy to understand its behaviour, performance and profile. Furthermore, the sophisticated UI of Heron topologies enable quick and efficient troubleshooting for issues.
Heron is able to handle large-scale topologies …show more content…
a) The Zipf discrete distribution derives from Zipf’s law which states that popularity of ith-most popular object is proportional to i-α, (α: Zipf coefficient). When applied to the words in English language, it means that the frequency of occurrence of a word is inversely proportional to its place in the frequently occurring words table ranked accordingly. Or in other words the most frequent word would occur nearly double times as the second most frequent word.
b) Heavy-tailed distributions are probability distributions whose tails are not exponentially bounded, or in other words they have heavier tails than the exponential distribution.
∀λ>0limy→+∞eλxP(Y>y)=+∞
(Function – is taken from outside source, I couldn’t find it on slides)
c) Zipf is based on rankings, when applied to searching of files, it means a popular file is searched double times than a second popular file among groups, whereas heavy-tail distribution means there is a higher probability for larger values to occur.
d)
Zipf:
1. File access Frequency
2. Describing income distributions (richest person makes twice more money as second richest)
3. Size of the cities (when measured with population)
4. Web access patterns are Zipf
Heavy-tailed:
1.