Hi Ja, How are the pending compactions distributed between the nodes? Run "nodetool compactionstats" on all of your nodes and check if the pendings tasks are balanced or they are concentrated in only few nodes. You also can check the if the SSTable count is balanced running "nodetool cfstats" on your nodes.
Cheers, Roni Balthazar On 25 February 2015 at 13:29, Ja Sam <ptrstp...@gmail.com> wrote: > I do NOT have SSD. I have normal HDD group by JBOD. > My CF have SizeTieredCompactionStrategy > I am using local quorum for reads and writes. To be precise I have a lot of > writes and almost 0 reads. > I changed "cold_reads_to_omit" to 0.0 as someone suggest me. I used set > compactionthrouput to 999. > > So if my disk are idle, my CPU is less then 40%, I have some free RAM - why > SSTables count is growing? How I can speed up compactions? > > On Wed, Feb 25, 2015 at 5:16 PM, Nate McCall <n...@thelastpickle.com> wrote: >> >> >>> >>> If You could be so kind and validate above and give me an answer is my >>> disk are real problems or not? And give me a tip what should I do with above >>> cluster? Maybe I have misconfiguration? >>> >>> >> >> You disks are effectively idle. What consistency level are you using for >> reads and writes? >> >> Actually, 'await' is sort of weirdly high for idle SSDs. Check your >> interrupt mappings (cat /proc/interrupts) and make sure the interrupts are >> not being stacked on a single CPU. >> >> >
