Timing an http server response using bash simple tools - bash

Question

Is that written on the title
I need it to measure a server load time, and in case this value is higher than a threshold, I restart the web server automatically.
How to time an http server response using simple GNU bash?

Answer 1

You could script and action the output of ab or apache benchmark. Also ensure you have %D enabled as a logformat. So rather than scripting a test you could script to tail log files and if time taken above threshold to restart.
Here is a script:
#!/bin/bash
# alert threshold - amount of times to go over limit before capturing it as an issue;
ALERT_THRESHOLD=3
# alert time in seconds
# so this is the time it takes to load the page anything exceeding set seconds
ALERT_LIMIT=60;
ALERT_LIMIT_MILI=$(echo $ALERT_LIMIT|awk '{$3=$1*1000; print $3}')
TAIL_LIMIT=10;
LOG_FILE="/var/log/apache2/access.log"
RESULT=$(tail -n $TAIL_LIMIT $LOG_FILE|awk -v alimit=$ALERT_LIMIT_MILI -v athreshold=$ALERT_THRESHOLD 'BEGIN{QUERY=""; i=0; SENDALERT=0} {
if ($1 > alimit) {
i++; QUERY=QUERY" TIME_TAKEN:"($1/1000)"seconds,"$1"ms|DATE:"$5"|STATUS:"$10"|URL:"$12"\n";
if (i >= athreshold){
SENDALERT++;
};
}
} END { print "QUERY:"QUERY"\nSENDALERT:"SENDALERT; }')
SENDALERT=$(echo -e $RESULT|awk -F"SENDALERT:" '{print $2}')
echo $SENDALERT
if [[ $SENDALERT >=1 ]]; then
echo "restaring apache"
content=$(echo -e $RESULT|awk -F"QUERY:" '{print $2}')
(for lines in $(echo $content); do echo $lines; done;)
#(for lines in $(echo $content); do echo $lines; done;)| mail -s "REstarting apache $(date) " root#localhost
fi
The alert time in seconds was set to 0 for my tests, you will see alert level 8,there are 10 lines that have these time values, so once variable i hits limit which is 3, it starts to inrement sendalert variable, this is why it reports it as 8, since the first two were passed as part of threshold.
running it:
./script.sh
ALERT LEVEL: 8
restaring apache
TIME_TAKEN:0.108seconds,108ms|DATE:[07/Mar/2013:22:12:51|STATUS:304|URL:"http://localhost/"
TIME_TAKEN:0.299seconds,299ms|DATE:[07/Mar/2013:22:12:51|STATUS:304|URL:"http://localhost/"
TIME_TAKEN:3.432seconds,3432ms|DATE:[07/Mar/2013:22:12:58|STATUS:200|URL:"-"
TIME_TAKEN:0.217seconds,217ms|DATE:[07/Mar/2013:22:12:58|STATUS:304|URL:"http://localhost/"
TIME_TAKEN:0.117seconds,117ms|DATE:[07/Mar/2013:22:12:58|STATUS:304|URL:"http://localhost/"
TIME_TAKEN:0.101seconds,101ms|DATE:[07/Mar/2013:22:12:58|STATUS:304|URL:"http://localhost/"
TIME_TAKEN:3.255seconds,3255ms|DATE:[07/Mar/2013:22:13:03|STATUS:200|URL:"-"
TIME_TAKEN:0.351seconds,351ms|DATE:[07/Mar/2013:22:13:03|STATUS:304|URL:"http://localhost/"
TIME_TAKEN:0.242seconds,242ms|DATE:[07/Mar/2013:22:13:03|STATUS:304|URL:"http://localhost/"
TIME_TAKEN:0.112seconds,112ms|DATE:[07/Mar/2013:22:13:03|STATUS:304|URL:"http://localhost/"
SENDALERT:8
---- apache access log:
108 127.0.0.1 - - [07/Mar/2013:22:12:51 +0000] "GET /icons/folder.gif HTTP/1.1" 304 186 "http://localhost/" "Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:19.0) Gecko/20100101 Firefox/19.0"
299 127.0.0.1 - - [07/Mar/2013:22:12:51 +0000] "GET /icons/compressed.gif HTTP/1.1" 304 188 "http://localhost/" "Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:19.0) Gecko/20100101 Firefox/19.0"
3432 127.0.0.1 - - [07/Mar/2013:22:12:58 +0000] "GET / HTTP/1.1" 200 783 "-" "Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:19.0) Gecko/20100101 Firefox/19.0"
217 127.0.0.1 - - [07/Mar/2013:22:12:58 +0000] "GET /icons/blank.gif HTTP/1.1" 304 186 "http://localhost/" "Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:19.0) Gecko/20100101 Firefox/19.0"
117 127.0.0.1 - - [07/Mar/2013:22:12:58 +0000] "GET /icons/folder.gif HTTP/1.1" 304 186 "http://localhost/" "Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:19.0) Gecko/20100101 Firefox/19.0"
101 127.0.0.1 - - [07/Mar/2013:22:12:58 +0000] "GET /icons/compressed.gif HTTP/1.1" 304 187 "http://localhost/" "Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:19.0) Gecko/20100101 Firefox/19.0"
3255 127.0.0.1 - - [07/Mar/2013:22:13:03 +0000] "GET / HTTP/1.1" 200 782 "-" "Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:19.0) Gecko/20100101 Firefox/19.0"
351 127.0.0.1 - - [07/Mar/2013:22:13:03 +0000] "GET /icons/folder.gif HTTP/1.1" 304 187 "http://localhost/" "Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:19.0) Gecko/20100101 Firefox/19.0"
242 127.0.0.1 - - [07/Mar/2013:22:13:03 +0000] "GET /icons/compressed.gif HTTP/1.1" 304 188 "http://localhost/" "Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:19.0) Gecko/20100101 Firefox/19.0"
112 127.0.0.1 - - [07/Mar/2013:22:13:03 +0000] "GET /icons/blank.gif HTTP/1.1" 304 186 "http://localhost/" "Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:19.0) Gecko/20100101 Firefox/19.0"
where I have put %D as first column output and in the awk statement in the script I am comparing $1's value against limit.. The rest of the $10's etc are according to where things appear in my log..
You could then put it in some script folder, remove verbosity or pump outut to dev null and run it as part of cron every 10 minutes or something
enjoy

Answer 2

This is a one-liner that solves the issue
(time wget -p --no-cache --delete-after www.example.com -q) 2>&1 >/dev/null | grep real | awk -F"[m\t]" '{ printf "%s\n", $2*60+$3 }'
it returns the load time of a page load in seconds and fraction of a second using a dot separator
time(5)
wget
awk