I may be wrong but during a bootstrap hints can be silently discarded, if the node they are destined for leaves the ring.
There are a large number of people using counters for 5 minute "real-time" statistics. On the back end they use ETL based reporting to compute the true stats at a hourly or daily interval. A user like this might benefit from DANGER counters. They are not looking for perfection, only better performance, and the counter row keys themselves role over in 5 minutes anyway. Options like this are also great for winning benchmarks. When someone other NoSQL (that is not has fast as c*) wants to win a benchmark they turn off/on WAL, or write acks, or something that compromises their ACID/CAP story for the purpose of winning. We need our own secret awesome-sauce dangerous options too! jk On Wed, Nov 28, 2012 at 4:21 AM, Rob Coli <rc...@palominodb.com> wrote: > On Tue, Nov 27, 2012 at 3:21 PM, Edward Capriolo <edlinuxg...@gmail.com> > wrote: > > I mispoke really. It is not dangerous you just have to understand what it > > means. this jira discusses it. > > > > https://issues.apache.org/jira/browse/CASSANDRA-3868 > > Per Sylvain on the referenced ticket : > > " > I don't disagree about the efficiency of the valve, but at what price? > 'Bootstrapping a node will make you lose increments (you don't know > which ones, you don't know how many and this even if nothing goes > wrong)' is a pretty bad drawback. That is pretty much why that option > makes me uncomfortable: it does give you better performance, so people > may be tempted to use it. Now if it was only a matter of replicating > writes only through read-repair/repair, then ok, it's pretty dangerous > but it's rather easy to explain/understand the drawback (if you don't > lose a disk, you don't lose increments, and you'd better use CL.ALL or > have read_repair_chance to 1). But the fact that it doesn't work with > bootstrap/move makes me wonder if having the option at all is not > making a disservice to users. > " > > To me anything that can be described as "will make you lose increments > (you don't know which ones, you don't know how many and this even if > nothing goes wrong)" and which therefore "doesn't work with > bootstrap/move" is correctly described as "dangerous." :D > > =Rob > > -- > =Robert Coli > AIM>ALK - rc...@palominodb.com > YAHOO - rcoli.palominob > SKYPE - rcoli_palominodb >
