Difference between revisions of "Resource Monitoring Tools"
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Jump to navigationJump to search| Line 48: | Line 48: | ||
#keep track of time | #keep track of time | ||
| − | date >> /var/log/networkalerts/$LOGFILE | + | date >> /var/log/networkalerts/$LOGFILE |
| − | ping -c 6 $SERVERIP >> /var/log/networkalerts/$LOGFILE | + | ping -c 6 $SERVERIP >> /var/log/networkalerts/$LOGFILE |
#nothing after ping, as we need return value | #nothing after ping, as we need return value | ||
#if return val is error (see man on ping regarding count and deadline) | #if return val is error (see man on ping regarding count and deadline) | ||
# == or -eq can be used. == is intuitive, therefore better | # == or -eq can be used. == is intuitive, therefore better | ||
| − | if test $? == 1 | + | if test $? == 1 |
| − | then | + | then |
#if file empty | #if file empty | ||
#[ -s FILE ] True if FILE exists and has a size greater than zero. Thus, you get "empty.txt" if "diff.txt" is not e> | #[ -s FILE ] True if FILE exists and has a size greater than zero. Thus, you get "empty.txt" if "diff.txt" is not e> | ||
| Line 62: | Line 62: | ||
# must be space between [ and -s and also last bracket. test brackets are unintuitive so don't use them. | # must be space between [ and -s and also last bracket. test brackets are unintuitive so don't use them. | ||
# if [ -s /var/log/networkalerts/$HISTORYFILE ] | # if [ -s /var/log/networkalerts/$HISTORYFILE ] | ||
| − | + | if test -s /var/log/networkalerts/$HISTORYFILE | |
then | then | ||
exit 5 | exit 5 | ||
| Line 72: | Line 72: | ||
echo "alertsent" > /var/log/networkalerts/$HISTORYFILE | echo "alertsent" > /var/log/networkalerts/$HISTORYFILE | ||
fi | fi | ||
| − | fi | + | fi |
</pre> | </pre> | ||
Revision as of 04:05, 16 October 2020
There are programs available to watch various aspects of your system.
iftop
See active internet connections. e.g.
# iftop -i eth1
Will show you websites that don't close a connection, when the tab is left open. A privacy and security nightmare. This is a reason why Javascript is bad.
vmstat
See RAM usage. Can be watched, to monitor swapping. e.g.
$ vmstat 3
Leave it running. It will update every 3 seconds.
iotop
See HDD accesses. e.g.
# iotop --only # iotop -o
only flag will show active processes only
# iotop -d 0.01 or -d 0.1
delay flag can be set to be faster than 1 second. Some writes are missed otherwise.
Monitor Library Reads from PID
$ ltrace -p -pidhere-
See what a program is doing. (Note: not available on ARM deb repos)
Monitor IP address up/down via ping
#!/bin/bash
SERVERIP=$1
LOGFILE=$1_$(date +%A)_LOG
HISTORYFILE=$1_$(date +%A)_LOCKFILE
NOTIFYEMAIL=myemail@address.com
#setup this script in cron each minute, and also
#crontab requires historyfile / lockfile to be blanked (echo "" > file) each day or each hour, whatever you prefer.
#mkdir /var/log/networkalerts
#e.g. $ script.sh <ipaddress>
# in /etc/crontab
#*/3 * * * * root /root/email_alerts/test_up.sh 192.168.1.1 #tune this frequency based on your priority
#0 */2 * * * root rm /var/log/networkalerts/*LOCKFILE
#0 0 * * * root rm /var/log/networkalerts/*$(date +%A)*LOG
#keep track of time
date >> /var/log/networkalerts/$LOGFILE
ping -c 6 $SERVERIP >> /var/log/networkalerts/$LOGFILE
#nothing after ping, as we need return value
#if return val is error (see man on ping regarding count and deadline)
# == or -eq can be used. == is intuitive, therefore better
if test $? == 1
then
#if file empty
#[ -s FILE ] True if FILE exists and has a size greater than zero. Thus, you get "empty.txt" if "diff.txt" is not e>
#https://stackoverflow.com/questions/9964823/how-to-check-if-a-file-is-empty-in-bash
#https://mywiki.wooledge.org/BashGuide/TestsAndConditionals for all the other tests like -s
# [! -s file] to invert didn't work because of missing spaces (i think)
# must be space between [ and -s and also last bracket. test brackets are unintuitive so don't use them.
# if [ -s /var/log/networkalerts/$HISTORYFILE ]
if test -s /var/log/networkalerts/$HISTORYFILE
then
exit 5
else
# Use your favorite mailer here:
# wiki.zoneminder.com/Email
echo "alert" | mutt -s "Network Down" -- $NOTIFYEMAIL
#lock file / history file
echo "alertsent" > /var/log/networkalerts/$HISTORYFILE
fi
fi
