MongoDB 3.1.7 is a development release not intended for production use and marks the beginning of the evolution into 3.2 series. This release includes fixes for several server-side issues, including permission problems with cluster management, aggregation stage performance, and memory allocation issues in WiredTiger journal. Additionally, it addresses some download-related issues and reports non-zero exit codes in the MongoDB shell when subprograms die. The release is part of the ongoing effort to improve the stability and performance of MongoDB.