[p2p-hackers] Distributed Snapshots

[Thomas Repantis]

Hi all,

Can someone verify whether I am correct in my understanding of the following:
The Chandy-Lamport algorithm [1] can produce a distributed snapshot of a
system only if *all* nodes are running the algorithm.

In other words, I am looking for a way to get a global snapshot of a system
of nodes say A, B, and C.  The caveat is that they might exchange messages
with node D, which will not run a snapshot algorithm.  I am not interested in
the state of D, but I need a consistent global snapshot of A, B, and C.

Am I correct in my understanding that Chandy-Lamport cannot help in this case?

Is there any other way to get a consistent global snapshot of such a
distributed system?

Many thanks!
Thomas

[1]
Distributed Snapshots: Determining Global States of a Distributed System
K. Mani Chandy, Leslie Lamport
ACM Transactions on Computer Systems 3, 1 (February, 1985), 63-75.
http://research.microsoft.com/users/lamport/pubs/chandy.pdf


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