Offset represent different "units" for each columns. On SSTables columns, you can see following histgrams:
20 4291637 24 28680590 29 3876198 It means your 4291637 read operations required 20 SStables to read, 28680590 ops required 24, so on. In Write/Read latency columns, Offset represents micro seconds. 3711340 read operations completed in 2 ms. Most of your row is between 925 ~ 1331 bytes. Most of your row has 925 ~ 1331 columns. maki 2011/7/26 Aishwarya Venkataraman <cyberai...@gmail.com> > > Hello, > > I need help understanding the output of cfhistograms option provided as part > of nodetool. > When I run cfhistograms on one node of a 3 node cluster, I get the following : > > Offset SSTables Write Latency Read Latency Row Size Column Count > 1 0 0 458457 0 0 > 2 0 0 3711340 0 0 > 3 0 0 12159992 0 0 > 4 0 0 14350840 0 0 > 5 0 0 7866204 0 0 > 6 0 0 3427977 0 0 > 7 0 0 2407296 0 0 > 8 0 0 2516075 0 0 > 10 0 0 5392567 0 0 > 12 0 0 4239979 0 0 > 14 0 0 2415529 0 0 > 17 0 0 1406153 0 0 > 20 4291637 0 380625 0 0 > 24 28680590 0 191431 0 0 > 29 3876198 0 141841 0 0 > 35 0 0 57855 0 0 > 42 0 0 15403 0 0 > 50 0 0 4291 0 0 > 60 0 0 2118 0 0 > 72 0 0 1096 0 0 > 86 0 0 662 0 0 > 179 0 0 115 173 173 > 215 0 0 70 35 35 > 258 0 0 48 0 0 > 310 0 0 41 404 404 > 372 0 0 37 0 0 > 446 0 0 22 975 975 > 770 0 0 12 3668 3668 > 924 0 0 4 10142 10142 > 1331 0 0 4 256983543 256983543 > What do these numbers mean ? How can I interpret the above data ? I found > some explanation here > http://narendrasharma.blogspot.com/2011/04/cassandra-07x-understanding-output-of.html, > but I did no understand this completely. > > Thanks, > Aishwarya
