Today our team made public our first release candidate of MongoDB 2.8, rc0.

Since June, beginning with MongoDB World 2014, I’ve been speaking publicly about MongoDB 2.8, and its headline features: document level locking and pluggable storage engines. What I haven’t said until now is just how related these two features are.

We’ve been working on our storage API for roughly a year, and with MongoDB 2.8 rc0, we’re rolling out the first fully supported and working storage engine integration: WiredTiger.

WiredTiger is a modern storage engine designed from the ground up and optimized to support high write performance, compression, and vertical scalability. By integrating the WiredTiger storage engine, MongoDB 2.8 will add document-level locking and high performance writes.

Migrating existing MongoDB instances to the new storage engine can be done with a rolling upgrade, the same process as is used to upgrade MongoDB versions. And as demonstrated at MongoDB World 2014, 2.8 supports mixed-mode deployments, so teams can test out the new engine before migrating entirely.

Our original storage engine, MMAPv1, will remain the default for this release, and is going from database-level to collection-level locking, offering a major win, completely maintenance free, to teams for which a storage engine upgrade is not a priority.

Please remember, rc0 is a release candidate! We can’t wait for our amazing community to take it for a spin and start giving us feedback, but we do not recommend you use it in production!

With every release of MongoDB, we try to offer our community the most important things they’ve been asking for. With v2.8, we hope we’ve done exactly that.