Thanks, Mark! A couple of other questions about the command:
* Does it show statistics for just the current node on which I am running, or for the entire cluster? * Are the read latencies shown the latencies within a single host, or are they the end-to-end latencies from the coordinator node? -Clint On Sun, Nov 16, 2014 at 10:05 AM, Mark Reddy <mark.l.re...@gmail.com> wrote: > Hi Clint, > > The values of SSTables, Write Latency and Read Latency will be reset on node > start/restart and after running the cfhistograms command itself. > > The values of Row Size and Column Count are calculated at startup and then > re-evaluated during compaction. > > > Mark > > > On 16 November 2014 17:12, Clint Kelly <clint.ke...@gmail.com> wrote: >> >> Hi all, >> >> Over what time range does "nodetool cfhistograms" operate? >> >> I am using Cassandra 2.0.8.39. >> >> I am trying to debug some very high 95th and 99th percentile read >> latencies in an application that I'm working on. >> >> I tried running nodetool cfhistograms to get a flavor for the >> distribution of read latencies and also to see how many SSTables our >> reads are using, and I saw different results yesterday versus this >> morning, so I assume the time window is fairly tight (like an hour or >> so). I vaguely recall Aaron Morton talking about this during the >> training course I took at Cassandra Summit, but I cannot find my notes >> and I think the behavior of the tool with regard to time windows >> changed from version to version. >> >> Thanks! >> >> -Clint > >
