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Jon_Pineda_1180's avatar
Jon_Pineda_1180
Icon for Nimbostratus rankNimbostratus
Mar 21, 2013

BigIP Marking Down a Site after a HTTP Health Check

Hi Guys,

 

On Local Traffic >> Monitors >> monitor_http

 

I have the following properties entered.

 

Interval: 5s

 

Timeout: 16s

 

Send String: GET /index.php HTTP/1.1\r\nHost: www.mywebsite.com\r\n\r\n

 

Receive String: 200 OK

 

Receive Disable String:

 

User Name:

 

Password:

 

Reverse: No

 

Transparent: No

 

 

This setting works fine for monitoring the http health check of www.mywebsite.com. However, BigIp sometimes marks this down...When I tried to review the log file the only dominant messages that i got before the error occurs is this.

 

12:40:04.000 AM [Wed Mar 13 00:40:04 2013] [error] [client 10.105.253.70] ModSecurity: Warning. Match of "rx ^OPTIONS$" against "REQUEST_METHOD" required. [file "/sites/www.mywebsite.com/conf/modsecurity.d/modsecurity_crs_21_protocol_anomalies.conf"] [line "36"] [id "960015"] [msg "Request Missing an Accept Header"] [severity "CRITICAL"] [hostname "www.mywebsite.com"] [uri "/index.php"] [unique_id "UUADJAppXKIAADKQhpUAAAAF"]

 

After reading BigIPs community forum with regards http health check. I am now contemplating of changing my configurations with this setting:

 

 

Send String: GET /index.php HTTP/1.1\r\nHost: www.mywebsite.com\r\nConnection: close\r\n

 

Receive String: 200\sOK or 200|OK

 

Will this settings do any good as opposed to the previous one that I had?

 

Thank you Admins.....

 

config
design

1 Reply

  • nitass's avatar
    nitass
    Icon for Employee rankEmployee
    Mar 21, 2013
    Send String: GET /index.php HTTP/1.1\r\nHost: www.mywebsite.com\r\nConnection: close\r\n

     

    Receive String: 200\sOK or 200|OKthere is change in send string syntax between each version.

     

     

    sol2167: Constructing HTTP requests for use with the HTTP or HTTPS application health monitor

     

    http://support.f5.com/kb/en-us/solutions/public/2000/100/sol2167.html

     

     

    for recv string, i think the previous one is also okay. by the way, have you tried to troubleshoot when problem was happening? Aaron has written excellent article about it as following.

     

     

    Troubleshooting Ltm Monitors by Aaron

     

    https://devcentral.f5.com/wiki/advdesignconfig.TroubleshootingLtmMonitors.ashx

     

     

    hope this helps.