Release Notes for MongoDB 1.6

Upgrading

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

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

Sharding

Sharding is now production-ready, making MongoDB horizontallyscalable, with no single point of failure. A single instance ofmongod can now be upgraded to a distributed cluster with zerodowntime when the need arises.

• Sharding
• Deploy a Sharded Cluster
• Convert a Replica Set to a Sharded Cluster

Replica Sets

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

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

• Replication
• Deploy a Replica Set
• Convert a Standalone to a Replica Set

Other Improvements

• The w option (and wtimeout) forces writes to be propagated to nservers before returning success (this works especially well withreplica sets)
• $or queries
• Improved concurrency
• $slice operator for returningsubsets 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 commandnow 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

• 1.6.5

1.5.x Release Notes

• 1.5.8
• 1.5.7
• 1.5.6
• 1.5.5
• 1.5.4
• 1.5.3
• 1.5.2
• 1.5.1
• 1.5.0

You can see a full list of all changes onJIRA.

Thank you everyone for your support and suggestions!