High CPU usage by Jboss process with default setting
kyosuke Aug 8, 2005 6:31 AMHi,
I am using Jboss 3.0.1, however CPU usage by its process become high( about 8% ) once every minute, although any Web access is not done.
Does anyone know about this spike?
I investigated what system call is made by jboss process at the time of the spike with "tusc" command.
The following is the result of tusc.
# tusc -s open -i PID
npen("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
open("jboss-3.0.1/server/A/conf/log4j.xml", O_RDONLY|O_LARGEFILE, 0666) = 70
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
open("jboss-3.0.1/server/A/conf/log4j.xml", O_RDONLY|O_LARGEFILE, 0666) = 70
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
The output is done every 5 seconds, and in this case, only one line was output every output.
I confirmed the spike occurs whenever the return value of open() is changed 85 to 70.
So, the change of the return value is done once every minute.
However I couldn't figure out the reason of the spike.
Next, I tried to confirm how the latest version of Jboss behaves.
I installed jboss-4.0.2, started it up, and confirmed if spike happens.
(Any configuration to jboss was not done.)
As the result, I confirmed Jboss process's CPU usage become high up to about 16% once every minute.
Therefore I believe this spike is Jboss's default behavior.
Why does this happen and is there any workaround for this spike?
Any information is appreciated.
Thanks,
Kyosuke