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One notable disadvantage of non-incremental requests is when multiple reconfigurations are proposed concurrently. Suppose that the initial configuration is A, B, C and one process proposes to add a server D whereas another proposes to remove B. If each process has to specify the full new configuration then the first process would propose A, B, C, D whereas the second would propose A, C. One of these would succeed first, suppose A, C. Then the second proposal should be aborted otherwise the resulting configuration would be A, B, C, D, again containing Bwhere B appears even though it was already removed.

With the incremental approach this would not happen. Here, a configuration can be viewed as a set of changes. The initial configuration is (+A, +B, +C) then in the scenario above the next configuration is (+A, +B, +C, -B) and last one is (+A, +B, +C, -B, +D). This allows all reconfiguration requests to complete without aborting (a wait-free algorithm).

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