incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From ruslan usifov <ruslan.usi...@gmail.com>
Subject Re: performance reaching plateau while the hardware is still idle
Date Thu, 15 Dec 2011 11:13:30 GMT
Use parallel test:-)))

2011/12/15 Kent Tong <freemant2000@yahoo.com>

> Hi,
>
> I am running a performance test for Cassandra 1.0.5. It can perform about
> 1500 business operation (one read+one write to the same row) per second.
> However, the CPU is still 85% idle (as shown by vmstat) and the IO
> utilization is less than a few percent (as shown by iostat). "nodetool
> tpstats" shows basically no active and pending threads. I can run several
> such test clients concurrently, achieving the same operations per second
> without increasing the hardware utilization. So, why the performance has
> reached a plateau while there is still idle hardware resources?
>
>
> Thanks in advance for any idea!
>

Mime
View raw message