Release Notes for MongoDB 1.6

Upgrading

MongoDB 1.6 is a drop-in replacement for 1.4. To upgrade, simply shutdown mongod then restart with the new binaries.

Please note that you should upgrade to the latest version of whichever driver you’re using. Certain drivers, including the Ruby driver, will require the upgrade, and all the drivers will provide extra features for connecting to replica sets.

Sharding

Sharding is now production-ready, making MongoDB horizontally scalable, with no single point of failure. A single instance of mongod can now be upgraded to a distributed cluster with zero downtime when the need arises.

Replica Sets

Replica sets, which provide automated failover among a cluster of n nodes, are also now available.

Please note that replica pairs are now deprecated; we strongly recommend that replica pair users upgrade to replica sets.

Other Improvements

  • The w option (and wtimeout) forces writes to be propagated to n servers before returning success (this works especially well with replica sets)
  • $or queries
  • Improved concurrency
  • $slice operator for returning subsets of arrays
  • 64 indexes per collection (formerly 40 indexes per collection)
  • 64-bit integers can now be represented in the shell using NumberLong
  • The findAndModify command now supports upserts. It also allows you to specify fields to return
  • $showDiskLoc option to see disk location of a document
  • Support for IPv6 and UNIX domain sockets

Installation

  • Windows service improvements
  • The C++ client is a separate tarball from the binaries

1.6.x Release Notes

1.5.x Release Notes

You can see a full list of all changes on JIRA.

Thank you everyone for your support and suggestions!