Actually its 256 Native Transport threads, the number of concurrent threads on
each node is 32. My main concern is, What amount of CPU capacity should i keep
free for tasks other than write that includes compaction and read? Sent using
Zoho Mail ============ Forwarded message ============ From : Elliott Sims
<elli...@backblaze.com> To : <user@cassandra.apache.org> Date : Fri, 07 Sep
2018 08:05:27 +0430 Subject : Re: Cluster CPU usage limit ============
Forwarded message ============ It's interesting and a bit surprising that 256
write threads isn't enough. Even with a lot of cores, I'd expect you to be
able to saturate CPU with that many threads. I'd make sure you don't have
other bottlenecks, like GC, IOPs, network, or "microbursts" where your load is
actually fluctuating between 20-100% CPU. Admittedly, I actually did get best
results with 256 threads (and haven't tested higher, but lower is definitely
not enough), but every advice I've seen is for a lower write thread count being
optimal for most cases. On Thu, Sep 6, 2018 at 5:51 AM, onmstester onmstester
<onmstes...@zoho.com> wrote: IMHO, Cassandra write is more of a CPU bound task,
so while determining cluster write throughput, what CPU usage percent (avg
among all cluster nodes) should be determined as limit? Rephrase: what's the
normal CPU usage in Cassandra cluster (while no compaction, streaming or
heavy-read running) ? For a cluster with 10 nodes, i got 700K write per seconds
for my data model, average cpu load is about 40%, i'm going to increase number
of native threads (now is 256) and native queue (1024) to increase throughput
(and CPU usage subsequently). Sent using Zoho Mail
