Ask HN: Log storage options?

I seem to remember a paper or open source project from Google that implements a circular store of logs. The logs are written in indexed chunks and the whole thing is optimized for 90% write, 10% read load.

It is surprisingly difficult to search for this. I've tried quite a few search terms and search engines (including HN's) and still no luck.

I'm hoping someone here can point me at such a thing.