Thanks for the quick reply! I completely forgot about proxyhistograms! On Sun, Nov 16, 2014 at 1:56 PM, DuyHai Doan <doanduy...@gmail.com> wrote:
> "Does it show statistics for just the current node on which I am running, > or for the entire cluster?" --> only current node. > > "Are the read latencies shown the latencies within a single host, or are > they the end-to-end latencies from the coordinator node?" --> cfhistograms > shows metrics at table/node level, proxyhistograms shows metrics at > cluster/coordinator level > > On Sun, Nov 16, 2014 at 10:31 PM, Clint Kelly <clint.ke...@gmail.com> > wrote: > >> 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 >> > >> > >> > >
