08809f5e6c
Summary: Implement trace sampling to allow user to specify the sampling frequency, i.e. save one per how many requests, so that a user does not need to log all if he/she is interested in only a sampled set. Pull Request resolved: https://github.com/facebook/rocksdb/pull/4963 Differential Revision: D14011190 Pulled By: tang-jianfeng fbshipit-source-id: 078b631d9319b67cb089dd2c30e21d0df8dc406a