* '''Election safety:''' at most one leader can be elected in a given term.
* '''Leader Appendappend-Onlyonly:''' a leader can only append new entries to its logs (it can neither overwrite nor delete entries).
* '''Log Matchingmatching:''' if two logs contain an entry with the same index and term, then the logs are identical in all entries up through the given index.
* '''Leader Completenesscompleteness:''' if a log entry is committed in a given term then it will be present in the logs of the leaders since this term
* '''State Machinemachine Safetysafety:''' if a server has applied a particular log entry to its state machine, then no other server may apply a different command for the same log.
The first four rules are guaranteed by the details of the algorithm described in the previous section. The State Machine Safety is guaranteed by a restriction on the election process.
