Change-Id: Ie35a09772e46f7d90cb68ca82c1d18b9201d1abe

* large scale kv store optimize

Change-Id: I582cc661afdaa20749ec7493eae1b88c32b967f7

* replace std::unorded_map with roundrobin map

Change-Id: I48ee0efef38853876c92d982cdfcac6603c52c88

* remove license

* fix cpp lint

Change-Id: Ia21fafa65adc09bb9094f7dbc987e31d5af2686e