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- besides latest and earliest, we also add nearest: reset to either latest or earliest depending on the current offset, it will only trigger for out-of-range. This parameter is disabled by default. To use it, you need to set "nearest.offset.reset=true". But when there is some partitions without committed offsets that need to reset offsets, one of earliest, latest, and safe_latest must be used together. Strictly speaking, nearest is not a level strategy with earlyliest/latest/safe_latest/earliest_on_start/latest_on_start. It is more like an auxiliary strategy, which is only dealt with out-of-range.
- latest-on-start, earliest-on-start: reset to either latest or earliest only when we see the partition for the first time without committed offset; when out-of-range default to none, i.e. throw exception.
- safe-latest: an additional limitTimeStamp parameter is used when reset offset. it means we only reset to latest / earliest if its partition's first record timestamp is smaller / larger than the given limitTimeStamp parameter, otherwise, reset to earliest / latest. set the limitTimeStamp value to the consumer group started timestamp, when new partitions are added it would reset to earliest to avoid losing data for problem mentioned in motivation.
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