Basic Monitoring

Default Monitors

You will be setting up a default monitor to test any node created. You can also choose to use custom monitors and monitor on a per node basis.

Go to Local Traffic > Nodes, note the status nodes.

As you can see the nodes in this table, even though they were never specifically configured in the Node portion of the GUI. Each time a unique IP address is placed in a pool a corresponding node entry is added and assigned the default monitor, if configured.

Also note, the node status is currently a blue square (Unchecked).

Q1. What would happen if a node failed?

Select the Default Monitors tab.

Notice you have several options, for nodes you want a generic monitor, so we will choose icmp.

Select icmp from Available and place it in Active.

Select Node List or Statistics from the top tab.

Q2. What are your node statuses?

Select Statistics > Module Statistics > Local Traffic

Q3. What are the statuses of your nodes, pool and virtual server?

Content Monitors

The default monitor simply tells us the IP address is accessible, but we really don’t know the status of the particular application the node supports. We are now going to create a monitor to specifically test the application we are interested in. We are going to check our web site and its basic authentication capabilities.

Browse to http://10.1.10.100 virtual server and select the Basic Authentication link under Authentication Examples. Log on with the credentials user.1/password.

Hint

You may have to scroll down the page to find the link.

You could use text from this page or text within the source code to test for availability. You could also use HTTP statuses or header information. You will be looking for the HTTP status 200 OK as the receive string to determine availability.

Note the URI is /basic/. You will need this for your monitor.

Select Local Traffic > Monitor on the side-bar and create and new HTTP monitor called www_test.

Name	www_test
Type	http
Send String	GET /basic/ \r\n
Receive String	200 OK
User Name	user.1
Password	password

Note

In case you were wondering, the receive string is NOT case sensitive.

By default, in v11.x (which you are being tested on) the default HTTP monitor uses HTTP v1.0. If you application required HTTP 1.1 you would require a different send string, something like GET /basic/ HTTP/1.1 \r\n Host: <host name>\r\n\r\n.

An excellent reference for crafting HTTP monitors can be found on ASK F5 at https://support.f5.com/csp/article/K2167.

Click Finish and you will be taken back to Local Traffic > Monitors

Do you see your new Monitor?

Hint

Check the lower right hand corner of the Monitors list, here you can go to the next page or view all Monitors. You can change the number of records displayed per page in System > Preferences.

Go to www_pool and replace the default http monitor with your www_test monitor.

Q1. What is the status of the pool and its members?

Q2. Go to Virtual Servers or Network Map , what is the status of your virtual server?

Just for fun Reverse the monitor. Now when 200 OK is returned it indicates the server is not responding successfully.

Q3. What is status of your pool and virtual server now?

You can see where this would be useful if you were looking for a 404 (bad page) or 50x (server error) response and pulling the failed member out of the pool.

Warning

Be sure to un-reverse your monitor before continuing.