09 Jul: Back in time: unreliable clocks and distributed computing

Many scalable NoSQL databases like Cassandra, HBase, Mongo, provide tunable consistency in order to define a specific guarantees level for an operation. And what make them scalable make them also vulnerable: in all case the whole cluster must run on synchronized clocks. It’s quite surprising that, given how important this is, it is not very detailled in the product documentation. One chapter in the HBase documentation, a pararaph in the MongoDB production readiness, a few lines in…