I'm also reading with CL = ONE 2012/1/5 Philippe <[email protected]>
> Depending on the CL you're reading at it will yes : if the CL requires > that the "slow" node create a digest of the data and send it to the > coordinator then it might explain the poor performance on reads. What is > your read CL ? > > 2012/1/5 R. Verlangen <[email protected]> > > As I posted this I noticed that the other node's CPU is running high on >> some other cronjobs (every couple of minutes to 60% usage). Is the lack of >> more CPU cycles a problem in this case? >> >> Robin >> >> 2012/1/5 R. Verlangen <[email protected]> >> >> CPU is idle (< 10% usage). Disk reads occasionally blocks over 32/64K. >>> Writes around 0-5MB per second. Network traffic 0.1 / 0.1 MB/s (in / out). >>> Paging 0. System int ~ 1300, csw ~ 2500. >>> >>> >>> 2012/1/5 Philippe <[email protected]> >>> >>>> What can you see in vmstat/dstat ? >>>> Le 5 janv. 2012 11:58, "R. Verlangen" <[email protected]> a écrit : >>>> >>>> Hi there, >>>>> >>>>> I'm running a cassandra 0.8.6 cluster with 2 nodes (in 2 DC's), RF = >>>>> 2. Actual data on the nodes is only 1GB. Disk latency < 1ms. Disk >>>>> throughput ~ 0.4MB/s. OS load always below 1 (on a 8 core machine with >>>>> 16GB >>>>> ram). >>>>> >>>>> When I'm running my writes against the cluster with cl = ONE all reads >>>>> appear to be faster then the writes. >>>>> >>>>> Average write speed = 1600us/operation >>>>> Average read speed = 200us/operation >>>>> >>>>> I'm really wondering why this is the case. Anyone got a clue? >>>>> >>>>> With kind regards, >>>>> Robin >>>>> >>>> >>> >> >
