Number of active tasks is controlled by concurrent_compactors yaml setting.
Recommendation is set to number of cpu cores you have.
Number of pending tasks is an estimate generated by Cassandra to achieve a
completely compacted state (i.e, there are no more possible compactions).
How this is estimated depends on the compaction strategies in use.
If you increase the compaction throughput it simply increases the rate at
which C* will compact, allocating more resources to reading/writing from
disk.
On 26 September 2017 at 08:20, Anshu Vajpayee
wrote:
> Hello -
>
> Ihave very generic question regarding compaction. How does cassandra
> internally generate the number of comapction tasks? How does it get
> affected with compaction throughput ?
>
> If we increase the number of compaction throughput, will the per second
> compaction task increase for same kind of write load ?
>
> Finally whats your recommendation for compaction throughput for SSDs?
>
> --
> *C*heers,*
> *Anshu *
>
>
>