General

• This release adds new diagnostic and performance analysis tools, and bug fixes since 1.2.0.

New features and improvements

• Added index usage stats. The db.coll.stats() command now shows cumulative statistics for how each index has been used since the last reboot. See the user's guide for more details. (#285, #286, #501)
• Added document-level lock debugging information. With new commands showLiveTransactions and showPendingLockRequests, you can show the state of all document-level locks currently held in TokuMX, which helps diagnose why a workload might get "lock not granted" or "deadlock" errors. In addition, when an operation fails for one of these reasons, some of this information is immediately printed to the error log. See the user's guide for more details. (#297, #437, #490)
• Added mongo shell wrapper functions db.beginTransaction(), db.commitTransaction(), db.rollbackTransaction(), and db.engineStatus(). (#488)
• Added to mongo2toku persistent save/resume functionality. When the tool exits, it will write the timestamp to a file, and resume from that file, rather than just by printing out the argument to use for the next invocation. (#495)
• Increased the default numInitialChunks for sharding empty collections on a hashed key. This should reduce the number of migrations experienced during an initial load or at the beginning of a workload. (#513)

Bug fixes

• Fixed a deadlock that occurred when multiple clients tried to create the same collection concurrently. (#477)
• Improved the reliability and usability of mongorestore when using the bulk loader. (#492, #512, #514, #515)
• Fixed a race condition that occurred when multiple clients tried to open the same database concurrently. (#499)
• Reduced lock contention for profiling and diagnostics logging. (#505, #506, #508)
• Includes a fix for a rare memory allocation error exposed by large keys in the fractal tree library. (Tokutek/ft-index#70)