How to remotely check if Apache server responds?

Question

I have 2 servers. One of them often crashes. I want to send a SMS to my phone when it crashes.

I wrote this simple bash script in another server and put it in crontab to run every 10 minutes.

wget --spider http://mywebsite.com || php sendsms.php

Is this the right way? Sometimes I get SMS, but I see that server is running without any problem.

Answer 1

You should be able to see from the output of wget --spider ... why wget has failed. That information is emailed to the user running the script or, if you use

[email protected]

you can redirect it to your email account for review.

If there are spurious network or DNS errors you can do a double check to see if unavailability was temporary, and thereby reducing the number of false positives:

wget --spider -a /var/tmp/wget_test.log http://mywebsite.com || (sleep 10; wget --spider http://mywebsite.com ) || php sendsms.php

Note that I have made the first try, append output to a log file (instead of printing to stderr). This way you don't get an email every 10 minutes if things run fine.

Every wget run first prints a date-timestamp and url when it tries that url. You will be able to review all runs that fail the first wget and pass the second by matching the date-timestamp from the emailed output of the second wget to that from the log file.