In this talk I’ll go into detail about Tumblr’s experience developing Motherboy, an eventually consistent inbox style storage system built around HBase. The SLA, write concurrency, data volume, and failure modes for this application created a number of challenges in developing a solution. The user homing scheme introduced additional complexity that made capacity planning tricky as we tried to trade off availability and cost. Performance testing of our workload, and automation to support that testing, also provided a number of valuable lessons. This talk will be most useful to people considering HBase for their application, but will have enough detail to be useful to current HBase users as well.