3 ms·
Though, it's not even remotely okay if your documentation and marketing material indicates that consistency isn't being sacrificed for performance. :) I suspec
by simoncion 11y ago
Though, it's not even remotely okay if your documentation and marketing material indicates that consistency isn't being sacrificed for performance. :)
I suspect that no experienced programmer expects to get data safety for free. We do expect that the documentation doesn't lie to us when describing the level of data safety provided.
- antirez 11y agoI totally agree, just a note: write safety and consistency are not the same thing. An example is a CP store that breaks linearizability in order to serve reads without asking other nodes, but just providing the local value. Writes are as safe as a true CP store, but the consistency model is different and weaker. It is true that many times the replication model employed also has effects on the ability of writes to survive, I just mentioned the above example to show it is not always the case.
- acconsta 11y agoRight, that's the real value here — holding databases accountable for their claims. Zookeeper clearly documented that writes are consistent but reads aren't, so it "passed" Jepsen cleanly. The Etcd guys claimed reads are linearizable, so Aphyr tested for linearizability and it failed. https://aphyr.com/posts/291-call-me-maybe-zookeeper https://aphyr.com/posts/291-call-me-maybe-zookeeper https://aphyr.com/posts/316-call-me-maybe-etcd-and-consul https://aphyr.com/posts/316-call-me-maybe-etcd-and-consul