Re: [jetty-users] CPU spikes caused by Selector threads

[Kohei Nozaki <kohei.nozaki@xxxxxxxxxx>]

Hi Greg, thank you so much for your help.

On 5/30/16 8:33 PM, Greg Wilkins wrote:
> A 100% CPU spike might suggest a bug, but a 65% spike could just be busy
> IO or even a DOS attack.

I have observed that there are some samples which indicates 100% CPU 
(i.e. 0.0%id) during the spike as follows:

$ grep 0.0%id top_h.txt
Cpu(s): 21.3%us, 37.1%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.5%si, 
41.1%st
Cpu(s): 23.8%us, 34.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.5%si, 
41.7%st
Cpu(s): 25.1%us, 32.9%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.5%si, 
41.4%st
Cpu(s): 24.4%us, 33.9%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.3%si, 
41.5%st
Cpu(s): 21.4%us, 36.5%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.8%si, 
41.4%st

Do these samples might suggest a bug? do you think of any relevant bugs 
that have been fixed in the latest Jetty?

Thanks,
Kohei