• Changes to allow safe downgrading from v2.6 to v2.4 SERVER-12914$^{746}$, SERVER-12175$^{747}$. 

• Fixes for edge cases in index creation SERVER-12481$^{748}$, SERVER-12956$^{749}$. 

• 2.4.10 Changelog (page 878). 

• All 2.4.10 improvements$^{750}$. 

## 2.4.9 – January 10, 2014 

• Fix for instances where mongos incorrectly reports a successful write SERVER-12146$^{751}$. 

• Make non-primary read preferences consistent with slaveOK versioning logic SERVER-11971$^{752}$. 

• Allow new sharded cluster connections to read from secondaries when primary is down SERVER-7246$^{753}$. 

• All 2.4.9 improvements$^{754}$. 

## 2.4.8 – November 1, 2013 

• Increase future compatibility for 2.6 authorization features SERVER-11478$^{755}$. 

• Fix dbhash cache issue for config servers SERVER-11421$^{756}$. 

• All 2.4.8 improvements$^{757}$. 

## 2.4.7 – October 21, 2013 

• Fixed over-aggressive caching of V8 Isolates SERVER-10596$^{758}$. 

• Removed extraneous initial count during mapReduce SERVER-9907$^{759}$. 

• Cache results of dbhash command SERVER-11021$^{760}$. 

• Fixed memory leak in aggregation SERVER-10554$^{761}$. 

• All 2.4.7 improvements$^{762}$. 

