MongoDB Documentation, Release 3.0.4 New Modular Authentication System with Support for Kerberos Additional Information Platform Notes Upgrade Process Upgrade Standalone mongod Instance to MongoDB 2.4 Chapter 12. Release Notes 892 $^{816}$http://www.mongodb.org/downloads/ $^{817}$http://www.mongodb.org/downloads Upgrade a Replica Set from MongoDB 2.2 to MongoDB 2.4 You can upgrade to 2.4 by performing a “rolling” up- grade of the set by upgrading the members individually while the other members are available to minimize downtime. Use the following procedure: See Security Enhancements (page 885) for more information. Upgrade Recommendations and Checklist When upgrading, consider the following: Upgrade MongoDB to 2.4 In the general case, the upgrade from MongoDB 2.2 to 2.4 is a binary-compatible “drop- in” upgrade: shut down the mongod instances and replace them with mongod instances running 2.4. However , before you attempt any upgrade please familiarize yourself with the content of this document, particularly the procedure for upgrading sharded clusters (page 893) and the considerations for reverting to 2.2 after running 2.4 (page 897). For OS X, MongoDB 2.4 only supports OS X versions 10.6 (Snow Leopard) and later. There are no other platform support changes in MongoDB 2.4. See the downloads page 816 for more information on platform support. For more information on security and risk management strategies, see MongoDB Security Practices and Procedures (page 317). In 2.4, the MongoDB Enterprise now supports authentication via a Kerberos mechanism. See Configure MongoDB with Kerberos Authentication on Linux (page 372) for more information. For drivers that provide support for Kerberos authentication to MongoDB, refer to Driver Support (page 333). • For all deployments using authentication, upgrade the drivers (i.e. client libraries), before upgrading the mongod instance or instances. • To upgrade to 2.4 sharded clusters must upgrade following the meta-data upgrade procedure (page 893). • If you’re using 2.2.0 and running with authorization enabled, you will need to upgrade first to 2.2.1 and then upgrade to 2.4. See Rolling Upgrade Limitation for 2.2.0 Deployments Running with auth Enabled (page 897). • If you have system.users documents (i.e. for authorization ) that you created before 2.4 you must ensure that there are no duplicate values for the user field in the system.users collection in any database. If you do have documents with duplicate user fields, you must remove them before upgrading. 1. Download binaries of the latest release in the 2.4 series from the MongoDB Download Page$^{817}$. See Install MongoDB (page 5) for more information. 2. Shutdown your mongod instance. Replace the existing binary with the 2.4 mongod binary and restart mongod .