[objectivefs]

ObjectiveFS does all the coordination among the clients through S3, so there is no extra coordination service needed. This is why we are really happy that Amazon recently moved the S3 us-east-1 region to read-after-write consistency (like all their other regions).

We do write bundling before sending data to S3 so lots of small files would be packed together and stored in a single S3 object. This also helps reduce the number of object store operations.

You are absolutely right that frequent sync will necessarily create many small objects, which is why small objects will be combined into bigger ones (this compaction is done in the background). Sync latency is of course bounded by the S3 PUT time, since fsync(2) can only return after your data has been safely stored in S3.

It is a really interesting design problem. Thanks for sharing your ideas.