what-when-how
In Depth Tutorials and Information
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Figure6.19
TheconnectivitymatrixfromthepreviousresultsbyAl-Hamraetal.
the connectivity matrix evolves. Figure 6.20 shows the connectivity matrix 4
hours further into the experiment in the middle of the transient stage, at which
point some peers have left and new peers have joined the system. he matrix is
now much more random, with many early peers having lost connections to leav-
ing peers and so allowing connections from many late peers, though the fan-out is
still visible in the lower left corner. Figure 6.21 goes further to 16 hours into the
experiment, where the connectivity matrix becomes an almost completely random
scattering of points, and the fan-out in the lower left is almost not visible. he
connectivity matrix has now reached a steady stage, as shown by the similarity of
Figures 6.21 and 6.22.
he experiment we ran with no limit on the number of neighbors a peer is
shown in Figure 1.23. In that experiment, the connectivity matrix throughout
the entire experiment was completely random (similar to Figure 1.22), as the
fan-out shape in Figure 1.18 is due only to the limit on the number of neighbors
a peer can have.
6.3.3.2 Impact of Churn
To further evaluate the impact of churn on the network topology, we varied
the amount of churn at certain points in the system by grouping some of the peer
