In order to avoid such cascading faults, it is better to make operators deterministic. Note however that it is easy for nondeterministic behavior to accidentally creep in: for example, many programming languages do not guarantee any particular order when iterating over elements of a hash table, many probabilistic and statistical algorithms explicitly rely on using random numbers, and any use of the system clock or external data sources is nondeterministic. Such causes of nondeterminism need to be removed in order to reliably recover from faults, for example by generating pseudorandom numbers
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