HTTP/HTTPS Health Monitor
Default Send String:
GET /\r\n
This will use HTTP0.9 request. Some servers may not support this version.
Below example for how to use HTTP1.1
GET / HTTP/1.1\r\nHost: <example.com>\r\nConnection: Close\r\n\r\n
A client MUST include HOST header field. Otherwise the server will return http/1.1 400 Bad Request error:
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html lang="en" xml:lang="en">
<head>
<title>Bad request!</title>
<link rev="made" href="mailto:root@localhost" />
<style type="text/css"><!--/*--><![CDATA[/*><!--*/
body { color: #000000; background-color: #FFFFFF; }
a:link { color: #0000CC; }
p, address {margin-left: 3em;}
span {font-size: smaller;}
/*]]>*/--></style>
</head>
<body>
<h1>Bad request!</h1>
<p>
Your browser (or proxy) sent a request that
this server could not understand.
</p>
<p>
If you think this is a server error, please contact
the <a href="mailto:root@localhost">webmaster</a>.
</p>
<h2>Error 400</h2>
<address>
<a href="/"> </a><br />
<span>Tue Jun 5 14:24:08 2018<br />
Apache</span>
</address>
[removed]if (top.pageUtilities) { top.pageUtilities.addFrameDocument(document); }[removed][removed]if (top.pageUtilities) { top.pageUtilities.addFrameDocument(document); }[removed]</body>
</html>
Receive string should match a key word in the reply from the server.
Example how to use OR to match either of the results:
Found|302|200
NOTE. Receive string will match first occurrence in the reply.
Before configuring Send and Receive strings we can simulate them in advance on LTM/GTM as a client and real destination HTTP/HTTPS server.
Use CLI to login onto LTM/GTM and get into advanced shell by typing:
bash
Monitor HTTP:
(echo -ne "Monitor String"; cat) | nc 'Pool Member IP' 'Pool member port'
Monitor HTTPS:
(echo -ne "Monitor String"; cat) | openssl s_client -connect 'Pool Member IP':'Pool member port' -quiet
Example:
(echo -ne "GET / HTTP/1.1\r\nHost: www.company.com\r\nConnection: Close\r\n\r\n"; cat) | nc 1.2.3.4 80
(echo -ne "GET / HTTP/1.1\r\nHost: www.company.com\r\nConnection: Close\r\n\r\n"; cat) | openssl s_client -connect 1.2.3.4:443 -quiet
Example of a reply:
HTTP/1.1 302 Found
Date: Tue, 05 Jun 2018 04:21:07 GMT
Server: Apache
X-Frame-Options: SAMEORIGIN
Set-Cookie:
Location:
Vary: Accept-Encoding
Connection: close
Transfer-Encoding: chunked
Content-Type: text/html; charset=iso-8859-1
298
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>302 Found</title>
</head><body>
<h1>Found</h1>
<p>The document has moved <a href="">here</a>.</p>
[removed]if (top.pageUtilities) { top.pageUtilities.addFrameDocument(document); }[removed]</body></html>
