I want to monitor the long running time cronjob.
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You could do:
#!/bin/bash
echo "Starting job blablabla" >>/tmp/job.log
date >>/tmp/duration.log
# THE REST OF THE CODE FOR SCRIPT blablabla
echo "End of job blablabla" >>/tmp/duration.log
date >>/tmp/duration.log
Every execution of the script will add entries with start and end time
Or directly in the cron:
* * * * * time -o /tmp/timing.txt blablabla.sh >/tmp/blablabla.out 2>/tmp/blablabla.out2
time -o shows the resource usage duration for the command.
The -o option specifies which file to send the results into.
The > and 2> redirections are to keep logs of the output and errors. But that is not related to time itself, just a good idea all around with cron jobs.
Related
I want to check if my scripts ran the last night(or last ran timestamp) on linux instance based on scripts crontab running time stamp.
So how to get scripts last ran time on linux instance?
I would suggest better record the start time during the start of the script and end time at the end of the Script.
# Start Time Entry
echo "Start : " $(date +%T) > exec.log
start=`date +%s`
CALL YOUR SCRIPT HERE
# End Time Entry
end=`date +%s`
echo "End : " $(date +%T) >> exec.log
# Get the Runtime
runtime=$((end-start))
echo "Runtime: $runtime" >> exec.log
If there is any better way, I am also curious to see and implement too.
grep cron from your "messages" or "syslog
grep -i cron /var/log/messages
or create a separate log file for cron from rsyslog, edit file /etc/rsyslog.conf and change #cron to cron. You will find logs in /var/log/cron
I got a simple cron job which simply prints the current date to a log file. For testing purposes, I've done this cron job to occur every minute.
crontab -u user01 -e
* * * * * echo "Date is $(date)" >> /home/user01/date.log
It was used to work before I created a logical volume, give ext4 format to this logical volume and mount it to /home/user01. After the mount operation, it doesn't do anything.
After this, I create a crontab with just (crontab -e), which means I dont give the username , and the crontab started to work again. But I want to know why my first crontab not working after mount.
Also, I know the /home/date.log will be deleted after mount operation but the crontab should write an output to date.log every minute .
For the record, there isn't any problem with mounting. I check /etc/fstab, and df -hT. The /home/user01 directory is mounted.
Also I have tried exact same cron job for another user(user02) in another directory, and it worked so there isn't any syntax or privilige issue.
Also when I check the /var/log/cron, below output come every minute
(user01) CMD (echo "Today is $(date)" >> /home/user01/date.log)
(user02) CMD (echo "Today is $(date)" >> /home/user02/date.log)
This output comes to log file every minute so that I guess the crontab is working but not giving the output for user01 or something.
Thank you for your help
You can login user01 to execute echo "Date is $(date)" >> /home/user01/date.log. success?
I need to run a curl request to locahost at least once in every 30 mins. So the command will be curl http://localhost:8080.
The catch here is, I want to select a time randomly between 5min - 30 min and then execute the curl command. The pseudo-code might look like this
while(true)
n = random number between 5-30
run curl http://localhost:8080 after 'n' minutes
A detailed answer would be nice since I don't have much knowledge about linux.
while true; do
sleep $(((RANDOM%25+5)*60))
curl http://localhost:8080
done
If you run above script, you must run as background process and make sure it will not be killed by something (OS, other users,...)
Another way is use cronjob to trigger automatically but the script is more complex.
Cronjob setting:
* * * * * bash test_curl.sh >> log_file.log
Shell script test_curl.sh:
#!/bin/bash
# Declare some variable
EXECUTE_TIME_FILE_PATH="./execute_time"
# load expected execute time
EXPECTED_EXECUTE_TIME=$(cat $EXECUTE_TIME_FILE_PATH)
echo "Start at $(date)"
# calculate current time and compare with expected execute time
CURRENT_MINUTE_OF_TIME=$(date +'%M')
if [[ "$EXPECTED_EXECUTE_TIME" == "$CURRENT_MINUTE_OF_TIME" ]];
then
curl http://localhost:8080
# Random new time from 5 -> 30
NEXT_RANDOM=$((RANDOM%25+5))
# Get current time
CURRENT_TIME=$(date +'%H:%M')
# Calculate next expected execute time = Current Time + Next Random
NEXT_EXPECTED_EXECUTE_TIME=$(date -d "$CURRENT_TIME $NEXT_RANDOM minutes" +'%M')
# Save to file
echo -n $NEXT_EXPECTED_EXECUTE_TIME > $EXECUTE_TIME_FILE_PATH
echo "Next Executed time is $(date -d "$CURRENT_TIME $NEXT_RANDOM minutes" +'%H:%M')"
else
echo "This $(date +'%H:%M') is not expected time to run test"
fi
echo "End at $(date)"
I commented out in line so you can read it easily.
**
Update: Importance: file execute_time must has initial value. For
example, the current minute of first time you execute.
**
Basic information about my system: I have a music system where people can schedule songs to start and end at a specific time.
OS: Arch linux
It sets two crons at the moment. One lets say at 1.50 (start time with a command like "play etc") and another set at 3.20 (end time with a command like "end etc").
My setup works perfectly and i can end delete schedules etc etc but i now noticed an issue! If i set the above times and turn the system off (My system is a raspberry pi) and turn back on at lets say 2.00 and i missed the 1.50 deadline, the music doesnt start (obviously) and i want to try make it so no matter what time i turn it on within a range lets say: 1.50 - 3.20 it will start the play command. But it will run the command once!
I looked around and the commands i got was like:
0 1.50-3.20/2 * * * your_command.sh
But thats to run every 2 hours. I want it to run once only between these times?
Thanks!
You could add an additional cron job which starts a script on every reboot. For instance, you could add a line like this to your crontab:
#reboot /home/pi/startplayback.sh
Your startplayback.sh script should check if current time is within the desired period and run the desired command if it is. For example the code below will print PLAY! if the script is run between 1:50 and 3:20. You could replace echo 'PLAY!' by run WHATEVER
#!/bin/bash
current=$(date '+%H%M')
(( current=(10#$current) ))
((current > 150 && current < 320 )) && echo 'PLAY!'
P.S. Don't forget to make your script executable sudo chmod +x startplayback.sh
You might want to look at the at command and its utilities.
SYNOPSIS
at [-q queue] [-f file] [-mldbv] time
at [-q queue] [-f file] [-mldbv] -t [[CC]YY]MMDDhhmm[.SS]
at -c job [job ...]
at -l [job ...]
at -l -q queue
at -r job [job ...]
atq [-q queue] [-v]
atrm job [job ...]
batch [-q queue] [-f file] [-mv] [time]
at is good for scheduling one time jobs to be run at some point in the future. It maintains a queue of these jobs, so you can use it to schedule things with a great variety of different time specifications.
Cron is in my opinion a scheduler for jobs that are to be repeated over and over.
So a quick and dirty example for you:
echo 'ls -lathF' | at now + 1 minute
As expected you will see a job to be run in one minute. Try atq to see the list of jobs.
When the job is done, output will be mailed to your user by default.
I solved the issue by creating a PHP file and load the page on reboot then do its work and redirect back to such and such.
I want to get the details of the last run cron job. If the job is interrupted due to some internal problems, I want to re-run the cron job.
Note: I don't have superuser privilege.
You can see the date, time, user and command of previously executed cron jobs using:
grep CRON /var/log/syslog
This will show all cron jobs. If you only wanted to see jobs run by a certain user, you would use something like this:
grep CRON.*\(root\) /var/log/syslog
Note that cron logs at the start of a job so you may want to have lengthy jobs keep their own completion logs; if the system went down halfway through a job, it would still be in the log!
Edit: If you don't have root access, you will have to keep your own job logs. This can be done simply by tacking the following onto the end of your job command:
&& date > /home/user/last_completed
The file /home/user/last_completed would always contain the last date and time the job completed. You would use >> instead of > if you wanted to append completion dates to the file.
You could also achieve the same by putting your command in a small bash or sh script and have cron execute that file.
#!/bin/bash
[command]
date > /home/user/last_completed
The crontab for this would be:
* * * * * bash /path/to/script.bash
/var/log/cron contains cron job logs. But you need a root privilege to see.
CentOs,
sudo grep CRON /var/log/cron