Shell bash代码无法运行且没有错误警告

Question

I write some shell bash to check if apache has wrong? I use curl my one page, if head return 200 ok , it seems apache run well, else, do service httpd restart , To monitor whether the script, i write some the run date and status into some log(1.txt).

apache.sh

#!/bin/bash
curl -I http://www.mydomain.com/check.php 2>/dev/null | head -1 | grep -q " 200 OK"
if [ $? -eq 0 ]; then echo "ok $(date)" >> 1.txt; else service httpd restart;echo "restart $(date)" >> 1.txt; fi

crontab

*/6 * * * * /bin/sh /home/username/apache.sh >/dev/null 2>&1

But yesterday, my apache still gone, (child process xxxx still did not exit, sending a SIGKILL).

I tried in ssh command line /bin/sh /home/username/apache.sh , no log has been writing(1.txt is empty) with no error warning.

Where is the problem? thanks.

Answer 1

You can try a simpler script like this:

rc=$(curl -Is -w '%{http_code}' -o /dev/null http://www.mydomain.com/check.php)
if [ $rc -eq 200 ]; then
    echo "ok $(date)" >> 1.txt
else
    service httpd restart
    echo "restart $(date)" >> 1.txt
fi

Answer 2

The service httpd restart will exit even when some of the child processes are still running - hence the msg child process xxxx still did not exit, sending a SIGKILL.
I have noticed this before, with db heavy websites (drupal, wordpress etc) and the solution is to stop apache, check if there are still child procs about and kill them, then restart apache.

service httpd stop
iter=0
# wait 30 seconds for any child procs to exit
while pgrep httpd
do
    iter=$(( iter + 1 ))
    if [ $iter -gt 6 ]
    then
         break
    fi
    sleep 5
done
# ok, I've finished waiting I'm going to kill 'em all
if pgrep httpd
then
    pkill -9 httpd
fi
service httpd start