Server failed, data corrupted and view intermittent

One of the Ubuntu servers auto-failover-ed tonight and although it came back up, we had some downtime reported on the website that uses it (so we still noticed a problem which we shouldn't have done as it should handle it shouldn't it?) and (at least) one of the documents was corrupted. This particular document is stored in bzcompress() format (via PHP) and is a relatively core piece of data to the website that uses it, so this had to be rebuilt. Fortunately it was only cached data rather than actual data but this is very concerning for me as I'm trying to move away from MySQL at the moment and rely solely on Couchbase but I can't have that data corrupted.

We also have some view queries ran on page load to retrieve certain things that are critical and whilst the rebalance was taking place the results of the view queries were intermittent to say the list. All queries were "stale=false" so it was trying to build the index each time, however according to the documentation it's supposed to handle this too.

I'm also unsure as to why the server failed in the first place as there doesn't look to have been anything wrong with the actual server.

I've ran the cbcollect_info and I've attached it. Any advice and/or recommendations on preventing this from happening again in the future is greatly received!

Will delete the zip from the server when someone can confirm it's ok to do so.

Thanks,

Graeme