Getting HTML Page Title for iRule

Hello, I believe this might be done much easier by implementing a HTTP monitor on pool members, where you can check HTTP response content.

Monitor will automatically mark the node offline if anything but expected content is seen.

To achieve redirect, you can use something like the following iRule

when CLIENT_ACCEPTED {
  if { [active_members http_pool] = 0 } {
    pool redirect_pool
  }
}

 ,

Thanks for you response, I have already tried health monitor but it does not fulfill the requirement.

Whenever the issue happens on Server in Pool-A it is still responding with 200 OK(desired received string) so F5 does not mark it down.

That's why I have come across with solution HTMP page title but now I am not sure how to fetch it from HTTP Response Header.

Also I am open to any other suggestions.

The title of the HTML page isn't part of any HTTP header. It's part of the document that's being returned by the webserver. So you'll need to enable the STREAM profile and use it to parse the response. The iRule below shows how to extract the title.

when HTTP_REQUEST {
    # Disable the stream filter by default   
    STREAM::disable 
 
    # LTM does not uncompress response content, so if the server has compression enabled
    # and it cannot be disabled on the server, we can prevent the server from
    # sending a compressed response by removing the compression offerings from the client
    HTTP::header remove "Accept-Encoding"
}
 
 
when HTTP_RESPONSE {
  # Check if response type is text
  if {[HTTP::header value Content-Type] starts_with "text"} {
 
    # match <title>...</title>
    STREAM::expression {=<title>[A-Za-z0-9\.\-]+==}
 
    # Enable the stream filter for this response only
    STREAM::enable
  }
}
 
when STREAM_MATCHED {
 
  # extract the title
  set title [string range [STREAM::match] 7 end]
 
  log local0.info "Title: $title"
}