Send and Receive String Explanation in a Http Monitor

Question

Hello &nbsp;
1---&nbsp;
I see for a http monitor below is the Send String Configured but at Receive String field nothing is  written/blank. &nbsp;
GET /index.html HTTP/1.1
Host: host.domain.com
Connection: Close

&nbsp;
My query is what is meant by Recieve String is being blank ?&nbsp;
2---&nbsp;
Also what is the technical difference if I do not put Index.html after the / Path  ?&nbsp;
GET /index.html HTTP/1.1
Host: host.domain.com
Connection: Close

GET / HTTP/1.1
Host: host.domain.com
Connection: Close

&nbsp;

dave_mccauley_3 · Answer

The receive string being blank means the big-ip won't look for any response. Basically as long as there's no TCP error, it should pass the check. Ideally you'd put something there such as "200 OK" or something that is in the page you're looking at.&nbsp;
If you don't put the index.html in the GET request, you're right, the pool member will probably respond with the index.html. Technically it will respond back with whatever the web server's configured default page is, such as in apache whatever the DirectoryIndex value is.&nbsp;
Health monitors will often work even though they're not configured properly, it's best to deliberately configure it rather than have it work and not know why. I'd recommend putting a file on the server and actually checking the content of the file. If it dynamically generates content such as pulling data from a database, a file that actually grabs something from the database would even be better!&nbsp;
I'm sure others will chime in with suggestions or other tips for health monitors.&nbsp;
HTH,&nbsp;
--D&nbsp;

rico · Answer

Subrun,&nbsp;

A blank receive string means that the HTTP monitor will mark its resource as UP if any response is received. A receive string is mainly used to parse the response and check that the proper resource is responding.&nbsp;

Changing the '/index.html' will change what resource that the request is looking for. A request with '/index.html' will attempt to return the contents of the 'index.html' file on the server the request was send to. If a GET request specified '/example.html' instead of '/index.html', it would attempt to return the contents of the 'example.html' file.&nbsp;

Here and here is some more documentation about HTTP monitors.&nbsp;

rico_368208 · Answer

Subrun,&nbsp;

A blank receive string means that the HTTP monitor will mark its resource as UP if any response is received. A receive string is mainly used to parse the response and check that the proper resource is responding.&nbsp;

Changing the '/index.html' will change what resource that the request is looking for. A request with '/index.html' will attempt to return the contents of the 'index.html' file on the server the request was send to. If a GET request specified '/example.html' instead of '/index.html', it would attempt to return the contents of the 'example.html' file.&nbsp;

Here and here is some more documentation about HTTP monitors.&nbsp;

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Send and Receive String Explanation in a Http Monitor

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