This is a great pleasure to announce the version bump of mongoDB to the brand new v2.6 stable branch !
This bump is not trivial and comes with a lot of changes, please read carefully as you will have to modify your mongodb configuration files !
As a long time request and to be more in line with upstream’s recommendations (and systemd support) I moved the configuration of the mongoDB daemons to /etc so make sure to adapt to the new YAML format.
- the mongodb configuration moved from /etc/conf.d/mongodb to the new YAML formatted /etc/mongodb.conf
- the mongos configuration moved from /etc/conf.d/mongos to the new YAML formatted /etc/mongos.conf
- the MMS agent configuration file has moved to /etc/mms-agent.conf
The init scripts also have been taken care of :
- new and modern mongodb, mongos and mms-agent init scripts
- their /etc/conf.d/ configuration files are only used to modify the init script’s behavior
The changelog is long and the goal of this post is not to give you an already well covered topic on the release notes but here are my favorite features :
- MongoDB preserves the order of the document fields following write operations.
- A new write protocol integrates write operations with write concerns. The protocol also provides improved support for bulk operations.
- MongoDB can now use index intersection to fulfill queries supported by more than one index.
- Index Filters to limit which indexes can become the winning plan for a query.
- Background index build allowed on secondaries.
- New cleanupOrphaned command to remove orphaned documents from a shard.
- usePowerOf2Sizes is now the default allocation strategy for all new collections.
- Removed upward limit of 20 000 connections for the maxIncomingConnections for mongod and mongos.
- New cursor.maxTimeMS() and corresponding maxTimeMS option for commands to specify a time limit.
Make sure you follow the official upgrade plan to upgrade from a previous version, this release is not a simple drop-in replacement.
Special thanks go to Johan Bergström for his continuous efforts and responsiveness as well as Mike Limansky and Jason A. Donenfeld.