When a monitoring check reaches or passes a specific threshold or value, an alarm is triggered and you'll receive a Warning or Critical email notification for the monitored resource. This article describes some simple troubleshooting steps that can help you diagnose the problem.
Ping checks typically monitor a server. If your ping check alarm is triggered, you should immediately try to contact your server using the ping command.
Issue the following command from an OS X Terminal window, Windows Command Prompt, or a Linux shell:
ping <target_hostname or ip_address>
The following ehow article provides some helpful information about how to read the results of a ping test: How to Read Ping Test Results.
The HTTP check is used to check websites. If you receive a notification from an HTTP check, try the following preliminary troubleshooting steps:
- Open the website in a browser to verify that the website is actually responding.
- If you are checking for specific content with a body match, verify that the content of the body match actually exists on the page that you are viewing.
Your browser returns the page or it might return another error saying that the site was unreachable or an error code from the web server. Common error codes include the following ones:
- 404, which means that the page was not found.
- 503, which means that the web server is denying access to the content that you are trying to view.
Advanced Troubleshooting for HTTP Checks
Run cURL, a common command-line web page utility, against the website that you are checking. This returns the contents of the web page to your terminal or shell window. You can explore cURL's options to get more specific information, but a useful option is -I. This command returns the target web page's headers and the response code from the web server. For example, enter the following command in your terminal or shell window, replacing your_domain with your actual domain:
curl -I http://www.your_domain.com
The output should look something like this:
HTTP/1.1 200 OK
Content-Type: text/html; charset=UTF-8
Last-Modified: Tue, 04 Sep 2012 20:00:05 GMT
P3P: CP="ALL DSP COR CUR ADMo DEVo TAIo PSAo PSDo IVAo CONi OTPi OUR NOR UNI"
Server: Apache Date: Tue, 04 Sep 2012 20:33:51 GMT
Connection: keep-alive Set-Cookie: target=us; path=/; domain=.your_domain.com Expires: Tue, 04 Sep 2012 21:00:00 GMT
TCP checks monitor ports. If an alarm is triggered for a TCP check, try to use Telnetto communicate with the target or scan your target for the open port.
Note: Ensure that you are authorized to scan the target. Many network security groups view this type of san as an attack on the open port.
Alternatively, try to directly access the service that is running on that port. For example, if the service is an SSH server, try to open an ssh session to the target host. If the service is running MYSQL or Microsoft SQL Server, try to connect to the database. Following is an example of how to use Telenet to communicate with the default port (3306) for MySQL:
telnet mysql.myhost.com 3306
To exit telnet, type Ctrl ], press Enter, and then type quit.
Contacting Rackspace Technical Support
If you're unable to solve the problem using the steps outlined in this article, contact Rackspace Technical Support by using the Cloud Control Panel. Your options for contacting Rackspace are as follows:
- Open a Support Ticket
- Use Live Chat
- Call the toll free number for your area
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