Hi Arthur, This is actually for a column in a counter column family, i.e. CounterColumnType. Will check out that thread though, thanks.
Best, Josh -- Josh Dzielak VP Engineering • Keen IO Twitter • @dzello (https://twitter.com/dzello) Mobile • 773-540-5264 On Monday, June 24, 2013 at 8:01 PM, Arthur Zubarev wrote: > Hi Josh, > > are you looking at the read counter produced by cfstats? > > If so it is not for a CF, but the entire KS and not tied to a specific > operation, but rather per the entire lifetime of JVM. > > Just in case, some supporting info: > http://stackoverflow.com/questions/9431590/cassandra-cfstats-and-meaning-of-read-write-latency > > /Arthur > > From: Josh Dzielak (mailto:j...@keen.io) > Sent: Monday, June 24, 2013 9:42 PM > To: user@cassandra.apache.org (mailto:user@cassandra.apache.org) > Subject: Counter value becomes incorrect after several dozen reads & writes > > > > > I have a loop that reads a counter, increments it by some integer, then goes > off and does about 500ms of other work. After about 10 iterations of this > loop, the counter value *sometimes* appears to be corrupted. > > Looking at the logs, a sequence that just happened is: > > Read counter - 15000 > Increase counter by - 353 > Read counter - 15353 > Increase counter by - 1067 > Read counter - 286079 (the new counter value is *very* different than what > the increase should have produced, but usually, suspiciously, around 280k) > Increase counter by - 875 > Read counter - 286079 (the counter stops changing at a certain point) > > > There is only 1 thread running this sequence, and consistency levels are set > to ALL. The behavior is fairly repeatable - the unexpectation mutation will > happen at least 10% of the time I run this program, but at different points. > When it does not go awry, I can run this loop many thousands of times and > keep the counter exact. But if it starts happening to a specific counter, the > counter will never "recover" and will continue to maintain it's incorrect > value even after successful subsequent writes. > > I'm using the latest Astyanax driver on Cassandra 1.2.3 in a 3-node test > cluster. It's also happened in development. Has anyone seem something like > this? It feels almost too strange to be an actual bug but I'm stumped and > have been looking at it too long :) > > Thanks, > Josh > > -- > Josh Dzielak > VP Engineering • Keen IO > Twitter • @dzello (https://twitter.com/dzello) > Mobile • 773-540-5264 > > > > > > >
