Under the Hood: Building and open-sourcing fbthrift

This post details the evolution of Facebook's internal Thrift framework into fbthrift. Key technical contributions include the adoption of folly's IOBuf for efficient memory management with chained buffers, enabling out-of-order responses and reducing memory allocation overhead. A new THeader protocol was introduced to support per-request features and attributes without modifying core libraries, enhancing flexibility and backward compatibility. The release of fbthrift includes a new C++ code generator (cpp2) which has shown up to 50% latency reduction and significant memory footprint decreases in production services. The asynchronous C++ code is also a dependency for HHVM.