Systems, methods, and computer storage media for storing and retrieving data from a data store in a distributed computing environment are provided. An embodiment includes receiving data at a data store comprising a sequential journal store, RAM, and a non-sequential target store. When RAM utilization is below a threshold, received data is stored to the RAM as a write cache for the target store and the journal store. But, when the utilization is above the threshold, the data is stored to the journal store without write-caching to the RAM for the target store. When the RAM utilization falls below a threshold, data committed to the journal store, but not write-cached to the RAM for the target store, is later read from the journal store and write-cached to the RAM for a target store.