As proposed at https://github.com/apache/incubator-kvrocks/issues/601 lz4 can bring a better compression ratio and performance in many scenarios and rocksdb also supported it as a compression library.
But the LICENSE <https://github.com/lz4/lz4/blob/dev/LICENSE> of lz4 was a bit confused, coz it said that: *- all files in the `lib` directory use a BSD 2-Clause license* *- all other files use a GPL v2 license unless explicitly stated otherwise* and some files like CMakeLists.txt <https://github.com/lz4/lz4/blob/dev/build/cmake/CMakeLists.txt> stated another license: zero 1.0. On the other hand, apache GPL Compatibility <https://www.apache.org/licenses/GPL-compatibility.html> stated that we can't include the GPL v3 projects and I'm NOT sure about whether we can include GPL v2 projects or not? -- Best Regards, - *Hulk Lin*
