MongoDB Documentation, Release 3.0.4 mongo Shell Version Compatibility Versions of the mongo shell before 3.0 are not compatible with 3.0 deploy- ments of MongoDB that enforce access control. If you have a 3.0 MongoDB deployment that requires access control, you must use 3.0 versions of the mongo shell. HTTP Status Interface and REST API Compatibility Neither the HTTP status interface nor the REST API sup- port the SCRAM-SHA-1 (page 321) challenge-response user authentication mechanism introduced in version 3.0. Remove dropDups Option dropDups option is no longer available for createIndex() , ensureIndex() , and createIndexes . Indexes Changes to Restart Behavior during Background Indexing For 3.0 mongod instances, if a background index build is in progress when the mongod process terminates, when the instance restarts the index build will restart as foreground index build. If the index build encounters any errors, such as a duplicate key error, the mongod will exit with an error. To start the mongod after a failed index build, use the storage.indexBuildRetry or --noIndexBuildRetry to skip the index build on start up. For $nearSphere queries that use a 2d (page 497) index, MongoDB no longer uses a default limit of 100 documents. 2d Indexes and Geospatial Near Queries For $near queries that use a 2d (page 497) index: Driver Compatibility Changes Each officially supported driver has release a version that includes support for all new features introduced in MongoDB 3.0. Upgrading to one of these version is strongly recommended as part of the upgrade process. A driver upgrade is necessary in certain scenarios due to changes in functionality: The minimum 3.0-compatible driver versions are: $^{232}$https://docs.mongodb.org/ecosystem/drivers/c $^{233}$https://github.com/mongodb/mongo-c-driver/releases Chapter 12. Release Notes 808 • Use of the SCRAM-SHA-1 authentication method • Use of functionality that calls listIndexes or listCollections • MongoDB no longer uses a default limit of 100 documents. • Specifying a batchSize() is no longer analogous to specifying a limit() . Driver Language Minimum 3.0-Compatible Version C 232 1.1.0 233 C++ 234 1.0.0 235 C# 236 1.10 237 Java 238 2.13 239 Node.js 240 1.4.29 241 Perl 242 0.708.0.0 243 PHP 244 1.6 245 Python 246 2.8 247 Motor 248 0.4 249 Ruby 250 1.12 251 Scala 252 2.8.0 253