This read-write object configures how many recent failure records the device retains in its session- and group-failure history tables, with a value of 0 explicitly disabling failure archiving altogether according to the desc. An admin who wants to keep enough forensic history to investigate an authentication attack, but not so much that it consumes excessive memory, tunes this value to balance retention depth against resource use. Setting this to 500, for instance, means only the 500 most recent failure records are kept, with older ones aged out as new failures occur.