100% CPU Usage

#1
Recently my webserver hanged few times in a week. After login into server to troubleshoot, found out the two lshttpd processes was 100% CPU utilised (refer attachment). Checked the access.log and error.log but seems like nothing unusual. After i excecute ./lswctrl stop and start again, it's seems like back to normal. Any advise?

I'm using Litespeed Web Server Enterprise v4.0.13 on CentOS, running HTTP and HTTPS with Tomcat and PHP and equipped with 2Mbps dedicated international bandwidth.
 

Attachments

NiteWave

Administrator
#2
when lshttpd reach 100%, can you capture a few seconds what it's doing?

#strace -p <pid-of-lshttpd>

also, output of "pstree -p", lshttpd subtree may give some clue.
 
Last edited:
#4
It's happens again right now.. one of lshttpd is now 100%, tried to run "strace -p <pid>" but it seems like no output (refer Clipboard02.jpg) and please refer tree.txt for the "pstree -p" output.


I also found out that I can't access my Litespeed Admin xxx.xxx.xxx.xxx:7080

Millions thanks.
 

Attachments

Last edited:

mistwang

LiteSpeed Staff
#7
to trouble shoot the 100% cpu issue, may need the debug build of lshttpd, and attach to the process with GDB.
Please contact bug@litespeedtech... for further assistance if need.
 
#8
After upgraded to 4.1RC2. The 100% cpu usage issue stil happend quite frequent, after that the webserver not responding.

Below is part of my litespeed setting:
Max Connections : 350
Connection Timeout (secs) : 100.
Max Keep-Alive Requests : 150.
Smart Keep-Alive : Yes
Keep-Alive Timeout (secs) : 10

The attached file was captured during the lshttpd 100% cpu usage.
#strace -p <pid-of-lshttpd>

Please advice.
 

Attachments

mistwang

LiteSpeed Staff
#9
strace does not tell us what code causes the infinity looping, can you please download a debug build of LSWS then use GDB to attach to it, then use command "bt" to get callback stack trace. Please contact bug@litespeedtech... for the debug build of LSWS.
 
#10
Hi, I'd tried to send email to bug@litespeedtech.com but the email was bounced back with the following message "550 This message was classified as SPAM with score 6.0 (state 18)"

Anyway, I've encounter one lshttpd 100% CPU usage at 6pm Malaysia time today and follow your instructions (please refer to my attachments).

Usually after one lshttpd process is 100% CPU usage, I'm no longer able to access the Litespeed's admin web control panel and after a while (few minutes? few hours?) the 2nd lshttpd process will also reached 100% CPU usage and caused the web server hanged.

From the gdb command, found this strange message "/home/gwang/release/httpd/httpd/extensions/jk/jconn.cpp: No such file or directory"

Please advice, thanks.
 

Attachments

Top