MongoDB 2.0 Released



The MongoDB development team is pleased to announce the release of version 2.0.0.  Version 2.0 is the latest stable release, following the March 2011 release of version 1.8.  This release includes many new features, improvements to existing features, and performance enhancements.

Please note version 2.0 is a significant new release, but is 2.0 solely because 1.8 + 0.2 = 2.0; for example the upgrade from 1.6 to 1.8 was similar in scope.

Highlights of the 2.0 release:

Concurrency improvements in 2.0 are just the start of a much larger concurrency roadmap we are working on.  In 2.0, we are beginning to address one of the biggest issues: holding locks during a page fault.  2.0 tracks memory caching and has the ability to yield locks and fault outside.  This is hooked in a number places, notably: updates by _id, remove, and long table scans.

Being able to keep the working index set in memory is an important factor in overall performance, and we overhauled indexes to make this easier.  Indexes in 2.0 are about 25% smaller and faster, meaning that you can fit more in memory.

Replica sets get two new important features in 2.0: priorities and tagging.  Priorities let you have nodes that you prefer to be primary if you have a non homogeneous environment.  Tagging lets you guarantee writes hit certain groups of servers.  One use case for this is guaranteeing a new user registration is written to two data centers before acknowledging to a user.

There were many other improvements, so we encourage those interested to look at the change log.  Overall, this release added a large number of small performance and concurrency improvements, greater stability to sharding, and better replica set operations.

<span >Downloads: <span ><span > 

<span >Release Notes: <span ><span > 

<span >Full change log:

For the full scoop on what’s new in MongoDB version 2.0, register for our live webinar on Thursday, September 15th. We will have two sessions: the first at 10am GMT, and another at 1:30pm ET/10:30am PT.

Thank you to the MongoDB community for your continued feedback and testing through the 1.9 development series.

-Eliot and the MongoDB Team