I'm puzzled by this problem I'm having on Ubuntu 20.04 where cron is able to run a bash script but the overall outcome is different then when using the shell command.
I've look through all questions I could in here and on Google but couldn't find anyone that had the same problem.
Background:
I'm using Pushgateway to store metrics I'm generating through a bash script, and afterwards it's being imported automatically to Prometheus.
The end goal is to export a list of running processes, their CPU%, Mem% etc, similar to top command.
This is the bash script:
#!/bin/bash
z=$(top -n 1 -bi)
while read -r z
do
var=$var$(awk 'FNR>7{print "cpu_usage{process=\""$12"\", pid=\""$1"\"}", $9z} FNR>7{print "memory_usage{process=\""$12"\", pid=\""$1"\"}", $10z}')
done <<< "$z"
curl -X POST -H "Content-Type: text/plain" --data "$var
" http://localhost:9091/metrics/job/top/instance/machine
I used to have a version that used ps aux but then I found out that it only shows the average CPU% per process.
As you can see, the command I'm running is top -n 1 -bi which gives me a snapshot of active processes and their metrcis.
I'm using awk to format the data, and FNR>7 because I need to ignore the first 7 lines which is the summery presented by top.
The bash scrip is registered on /bin, /usr/bin and /usr/local/bin.
When checking http://localhost:9091/metrics, which is supposed to show me the information gathered, I'm getting this some of information when running the scrip using shell:
cpu_usage{instance="machine",job="top",pid="114468",process="php-fpm74"} 17.6
cpu_usage{instance="machine",job="top",pid="114483",process="php-fpm74"} 11.8
cpu_usage{instance="machine",job="top",pid="126305",process="ffmpeg"} 64.7
And this is the same information when cron is running the same script:
cpu_usage{instance="machine",job="top",pid="114483",process="php-fpm+"} 5
cpu_usage{instance="machine",job="top",pid="126305",process="ffmpeg"} 60
cpu_usage{instance="machine",job="top",pid="128777",process="php"} 15
So, for some reason, when I run it from cron it cuts the process name after 7 places.
I initially though it was related to the FNR>7 but even after changing it to 8 or 9 (and using exec bash to re-register the command) it gives the same results, also when I run it manually it works just fine.
Any help would be appreciated!!
Related
I have some checks that I do every 2 hours to monitor the status of servers like
iostat -ch, df -h /DATA, free -mh, ps -aux | grep kafka and other commands and some shell scripts.
How can I group them in one or two scripts to execute them automatically without doing the same check manually every time?
So if I understand correctly you want to execute a bunch of commands as one script executed it automatically every two hours?
Start by writing a shell script:
#!/bin/sh
iostat -ch
df -h /DATA
free -mh
ps -aux | grep kafka
and then add it as a cron job (see cron)
I have 2 scripts that I'm testing to automate starting services on my server however they behave weirdly.
The first script is
#!/bin/sh
screen -dmS Test_Screen
sleep 1
sudo sh cd.sh
echo "finished"
Which runs perfectly however the script it runs does not and is as follows
#!/bin/sh
screen -S Test_Screen -X stuff "cd /home/Test"
sleep 1
screen -S Test_Screen -X eval "stuff \015"
sleep 1
echo "Complete"
The second script will run perfect if I run it from command line and will CD into the directory within the screen. However, if it runs from the first script it Will Not CD into the correct directory within the screen, but it will still print "Complete".
I'm Using CENTOS 6.7 and the latest version of GNU screen
Any Ideas?
This seems to be a problem with session nesting.
In your first script you create a session named Test_Screen.
In your second script the -S parameter tells screen to create a session of the same name. This might cause screen to exit and not cd into the correct directory.
You could move the cd command in front of the sudo sh cd.sh and remove those screen calls from the second script leaving only
stuff \015
echo "Complete"
Using the correct screenflags should also work.
#!/bin/sh
screen -dr Test_Screen -X stuff "cd /home/Test"
sleep 1
screen -dr Test_Screen -X eval "stuff \015"
sleep 1
echo "Complete"
For a more modern alternative to screen, have a look at tmux.
Ok so this turned out really weird. After posting i tried a couple of things on a centos 6.7 hyper V test environment and got the exact same issue. However, later in the day we ended up changing service provider and upgrading to centos 7 in the process. I am not sure why but since the update the script now runs perfectly and i was able to actually merge the two scripts into one in order to make it more efficient. If anyone knows why the update fixed it feel free to let me know.
I've a number of accounts running cron-started php jobs hourly.
The generic structure of the command is this:
wget -q -O - http://some.site.com/cron.php
Now, this used to be running just fine.
Lately, though, on a number of accounts it has started playing up - but only on this one server. Once or twice a day the php file is not run.
The access log is missing the relevant entry.
While the cron log shows that the job was run.
We've added a bit to the command to log things out (-o /tmp/logfile) but it shows nothing.
I'm at a loss, really. I'm looking for ideas what can be wrong, or how to sidestep this issue as it has started taking up way too much of my time.
Has anyone seen anything remotely like this?
Thanks in advance!
Try this command
wget -d -a /tmp/logfile -O - http://some.site.com/cron.php
With -q you turn off wget's output. With -d you turn on debug output (maybe -v for verbose output is already enough). With -a you append logging messages to /tmp/logfile instead of always creating a new file.
You can also use curl:
curl http://some.site.com/cron.php
On my private network I have a backup server, which runs a bacula backup every night. To save energy I use a cron job to wake the server, but I haven't found out, how to properly shut it down after the backup is done.
By the means of the bacula-director configuration I can call a script during the processing of the last backup job (i.e. the backup of the file catalog). I tried to use this script:
#!/bin/bash
# shutdown server in 10 minutes
#
# ps, 17.11.2013
bash -c "nohup /sbin/shutdown -h 10" &
exit 0
The script shuts down the server - but apparently it returns just during the shutdown,
and as a consequence that last backup job hangs just until the shutdown. How can I make the script to file the shutdown and return immediately?
Update: After an extensive search I came up with a (albeit pretty ugly) solution:
The script run by bacula looks like this:
#!/bin/bash
at -f /root/scripts/shutdown_now.sh now + 10 minutes
And the second script (shutdown_now.sh) looks like this:
#!/bin/bash
shutdown -h now
Actually I found no obvious method to add the required parameters of shutdown in the syntax of the 'at' command. Maybe someone can give me some advice here.
Depending on your backup server’s OS, the implementation of shutdown might behave differently. I have tested the following two solutions on Ubuntu 12.04 and they both worked for me:
As the root user I have created a shell script with the following content and called it in a bash shell:
shutdown -h 10 &
exit 0
The exit code of the script in the shell was correct (tested with echo $?). The shutdown was still in progress (tested with shutdown -c).
This bash function call in a second shell script worked equally well:
my_shutdown() {
shutdown -h 10
}
my_shutdown &
exit 0
No need to create a second BASH script to run the shutdown command. Just replace the following line in your backup script:
bash -c "nohup /sbin/shutdown -h 10" &
with this:
echo "/sbin/poweroff" | /usr/bin/at now + 10 min >/dev/null 2>&1
Feel free to adjust the time interval to suit your preference.
If you can become root: either log in as, or sudo -i this works (tested on ubuntu 14.04):
# shutdown -h 20:00 & //halts the machine at 8pm
No shell script needed. I can then log out, and log back in, and the process is still there. Interestingly, if I tried this with sudo in the command line, then when I log out, the process does go away!
BTW, just to note, that I also use this command to do occasional reboots after everyone has gone home.
# shutdown -r 20:00 & //re-boots the machine at 8pm
I have a basic script that outputs various status messages. e.g.
~$ ./myscript.sh
0 of 100
1 of 100
2 of 100
...
I wanted to wrap this in a parent script, in order to run a sequence of child-scripts and send an email upon overall completion, e.g. topscript.sh
#!/bin/bash
START=$(date +%s)
/usr/local/bin/myscript.sh
/usr/local/bin/otherscript.sh
/usr/local/bin/anotherscript.sh
RET=$?
END=$(date +%s)
echo -e "Subject:Task Complete\nBegan on $START and finished at $END and exited with status $RET.\n" | sendmail -v group#mydomain.com
I'm running this like:
~$ topscript.sh >/var/log/topscript.log 2>&1
However, when I run tail -f /var/log/topscript.log to inspect the log I see nothing, even though running top shows myscript.sh is currently being executed, and therefore, presumably outputting status messages.
Why isn't the stdout/stderr from the child scripts being captured in the parent's log? How do I fix this?
EDIT: I'm also running these on a remote machine, connected via ssh using pseudo-tty allocation, e.g. ssh -t user#host. Could the pseudo-tty be interfering?
I just tried your the following: I have three files t1.sh, t2.sh, and t3.sh all with the following content:
#!/bin/bash
for((i=0;i<10;i++)) ; do
echo $i of 9
sleep 1
done
And a script called myscript.sh with the following content:
#!/bin/bash
./t1.sh
./t2.sh
./t3.sh
echo "All Done"
When I run ./myscript.sh > topscript.log 2>&1 and then in another terminal run tail -f topscript.log I see the lines being output just fine in the log file.
Perhaps the things being run in your subscripts use a large output buffer? I know when I've run python scripts before, it has a pretty big output buffer so you don't see any output for a while. Do you actually see the entire output in the email that gets sent out at the end of topscript.sh? Is it just that while the processes run you're not seeing the output?
try
unbuffer topscript.sh >/var/log/topscript.log 2>&1
Note that unbuffer is not always available as a std binary in old-style Unix platforms and may require a search and installation for a package to support it.
I hope this helps.