HTTP monitor recv string

I'd guess there is an inferred case insensitivity flag added to the evaluation of the receive string against the response content. SOL4186 gives details on the escape sequences which can be used in a monitor send or receive string:

 

 

SOL4186: Entering escape sequences in an ECV health monitor's send and receive strings

 

https://support.f5.com/kb/en-us/solutions/public/4000/100/sol4186.html

 

 

Maybe you could enter the escape sequences for the characters in uppercase (using the hex values for the characters in this format: \xHH)? Else is there another string that you can match on that appears only in a successful response?

 

 

Aaron

Nice reference, thanks. I was thinking I saw somewhere we could use hex codes, but I couldn't find the doc in a pinch. Given the way our application infrastructure is designed, there is no other string we can look for. In the end, we tried a simple regular expression that worked fortunately. After having a bit more time I found this:

 

 

SOL5917 - Using regular expressions in a health monitor receive string

 

https://support.f5.com/kb/en-us/solutions/public/5000/900/sol5917.html

 

 

It just seems like a simple question like "are recv strings case sensitive?", or "what types of strings can be used in a monitor recv string?" are either very difficult to find, or is not addressed at all in the doc. And that is the type of thing that is really frustrating as a customer. I don't know, maybe my problem is with the search feature of ask.f5.com and not the doc...

 

 

Thanks Hoolio.

Another fine reference Hoolio - what would the community be without you?

 

 

I posted my feedback there. That type of forum was a very smart idea.

Hi,

 

 

I have a small question regarding the receive string as well.

 

I'm trying to setup a http monitor at a F5 GTM 9.4.8 HF4, which should detect the following string:

 

"running (lb)"

 

I tried different strings in the receive string field, but none worked:

 

"running \(lb\)" - escaping the brakets

 

"running (lb) - without escaping the brakets

 

The only receive string that worked is "running" but this is not sufficient, because I need to catch the "(lb)" part as well.

 

 

If I test the string "running (lb)" against the regex "running \(lb\)" at http://www.sweeting.org/mark/html/revalid.php I get a match, but the LTM marks the server as down.

 

 

BR

 

Jens

Hi Jens,

 

 

Can you try using \x_28 and \x_29 without the underscores:

 

 

running \x_28lb\x_29

 

 

SOL4186: Entering escape sequences in an ECV health monitor's send and receive strings

 

https://support.f5.com/kb/en-us/solutions/public/4000/100/sol4186.html

 

 

Aaron