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Daniel_55334's avatar
Daniel_55334
Icon for Altostratus rankAltostratus
Jun 16, 2011

URL monitoring problem

2 different web servers have to be monitored by LTM with version 10.2.0.

 

1 is 10.10.1.32 with monitoring URL http://10.10.1.32/Web/status.htm. It returns "Running" and I turn on debug with following messages.

 

 

 

2011-06-16 17:01:09.458329: ID 23 :(_send_active_service_ping): writing [ addr=::ffff:10.10.1.32:80 srcaddr=::ffff:10.10.1.7:54665 ] send=GET /Web/status.htm HTTP/1.1\x0d\x0aHost: 10.10.1.32\x0d\x0aConnection: Close\x0d\x0a\x0d\x0a

 

2011-06-16 17:01:09.458436: ID 23 :(_send_active_service_ping): sent ping [ addr=::ffff:10.10.1.32:80 srcaddr=::ffff:10.10.1.7:54665 ]

 

2011-06-16 17:01:09.458527: ID global:(_main_loop): about to select for 0.100000s

 

2011-06-16 17:01:09.458986: ID 23 :(_main_loop): rfd selected [ addr=::ffff:10.10.1.32:80 srcaddr=::ffff:10.10.1.7:54665 fd=9 pend=0 ]

 

2011-06-16 17:01:09.459065: ID 23 :(_recv_active_service_ping): reading [ addr=::ffff:10.10.1.32:80 srcaddr=::ffff:10.10.1.7:54665 ]

 

2011-06-16 17:01:09.459163: ID 23 :(_recv_active_service_ping): rcvd 304 bytes: -->HTTP/1.1 200 OK\x0d\x0aContent-Type: text/html\x0d\x0aLast-Modified: Tue, 14 Jun 2011 08:06:52 GMT\x0d\x0aAccept-Ranges: bytes\x0d\x0aETag: "036a946a2acc1:0"\x0d\x0aServer: Microsoft-IIS/7.5\x0d\x0aX-Powered-By: ASP.NET\x0d\x0aDate: Thu, 16 Jun 2011 09:06:15 GMT\x0d\x0aConnection: close\x0d\x0aContent-Length: 41\x0d\x0a\x0d\x0a\x0d\x0a\x0d\x0aRunning\x0d\x0a\x0d\x0a<-- [ addr=::ffff:10.10.1.32:80 srcaddr=::ffff:10.10.1.7:54665 ]

 

2011-06-16 17:01:09.459257: ID 23 :(_recv_active_service_ping): Response matched regex [ addr=::ffff:10.10.1.32:80 srcaddr=::ffff:10.10.1.7:54665 ] send=GET /Web/status.htm HTTP/1.1\x0d\x0aHost: 10.10.1.32\x0d\x0aConnection: Close\x0d\x0a\x0d\x0a

 

recv=Running

 

disable=

 

 

 

monitor configuration:

 

monitor monitor_10.10.1.32_1 {

 

defaults from http

 

recv "Running"

 

send "GET /Web/status.htm HTTP/1.1\r\nHost: 10.10.1.32\r\nConnection: Cl

 

ose\r\n\r\n"

 

}

 

 

 

 

Actually this monitor works find.

 

 

 

However I have another similar monitor which does not work properly. 10.10.1.12 with monitoring URL http://10.10.1.12/health/health.aspx. It returns "OK" and my monitor is configured to match "OK". When the server returns "NOTOK" on purpose, the monitor still deem the response as matched, with following debug message.

 

 

 

2011-06-16 17:01:07.455238: ID 11 :(_send_active_service_ping): writing [ addr=::ffff:10.10.1.12:80 srcaddr=::ffff:10.10.1.7:34974 ] send=GET /health/health.aspx HTTP/1.1\x0d\x0aHost: 10.10.1.12\x0d\x0aConnection: Close\x0d\x0a\x0d\x0a

 

2011-06-16 17:01:07.455344: ID 11 :(_send_active_service_ping): sent ping [ addr=::ffff:10.10.1.12:80 srcaddr=::ffff:10.10.1.7:34974 ]

 

2011-06-16 17:01:07.455465: ID global:(_main_loop): about to select for 0.100000s

 

2011-06-16 17:01:07.457013: ID 11 :(_main_loop): rfd selected [ addr=::ffff:10.10.1.12:80 srcaddr=::ffff:10.10.1.7:34974 fd=9 pend=0 ]

 

2011-06-16 17:01:07.457131: ID 11 :(_recv_active_service_ping): reading [ addr=::ffff:10.10.1.12:80 srcaddr=::ffff:10.10.1.7:34974 ]

 

2011-06-16 17:01:07.457223: ID 11 :(_recv_active_service_ping): rcvd 277 bytes: -->HTTP/1.1 200 OK\x0d\x0aCache-Control: private\x0d\x0aContent-Type: text/html; charset=utf-8\x0d\x0aServer: Microsoft-IIS/7.5\x0d\x0aX-AspNet-Version: 2.0.50727\x0d\x0aX-Powered-By: ASP.NET\x0d\x0aDate: Thu, 16 Jun 2011 09:06:14 GMT\x0d\x0aConnection: close\x0d\x0aContent-Length: 39\x0d\x0a\x0d\x0a\x0d\x0a\x0d\x0aNOTOK\x0d\x0a\x0d\x0a<-- [ addr=::ffff:10.10.1.12:80 srcaddr=::ffff:10.10.1.7:34974 ]

 

2011-06-16 17:01:07.457316: ID 11 :(_recv_active_service_ping): Response matched regex [ addr=::ffff:10.10.1.12:80 srcaddr=::ffff:10.10.1.7:34974 ] send=GET /health/health.aspx HTTP/1.1\x0d\x0aHost: 10.10.1.12\x0d\x0aConnection: Close\x0d\x0a\x0d\x0a

 

recv=OK

 

disable=

 

 

 

monitor configuration:

 

monitor monitor_10.10.1.12_1 {

 

defaults from http

 

recv "OK"

 

send "GET /health/health.aspx HTTP/1.1\r\nHost: 10.10.1.12\r\nConnection: Clo

 

se\r\n\r\n"

 

}

 

 

 

 

 

 

Could someone shield some light on this? Many thanks!

 

 

 

Daniel

 

management
monitoring

12 Replies

  • hoolio's avatar
    hoolio
    Icon for Cirrostratus rankCirrostratus
    Jun 16, 2011
    Hi Daniel,

     

     

    The problem is that the receive string of OK is being matched even when the server returns NOTOK. Can you try this regex in the receive field (removing all of the spaces)?

     

     

    ( ? < ! N O T ) O K

     

     

    It should match OK only if it's not preceded by NOT.

     

     

    $ cat test.html

     

    this line only contains OK so it should match

     

    this line contains NOTOK so it should not match

     

     

    $ grep -P '( ? < ! N O T ) O K' test.html

     

    this line only contains OK so it should match

     

     

    Aaron

     

     

  • Daniel_55334's avatar
    Daniel_55334
    Icon for Altostratus rankAltostratus
    Jun 16, 2011
    Thanks for your prompt reply. However I got this error message during configuration (I removed all spaces)

     

     

    01070753:3: Monitor monitor_10.51.1.12_1 recv parameter contains an invalid regular expression (Invalid preceding regular expression).

     

     

    I am sorry that I don't know much about regular expression.
  • Daniel_55334's avatar
    Daniel_55334
    Icon for Altostratus rankAltostratus
    Jun 16, 2011
    Hi hoolio,

     

     

    From your reply I think what I need is a regex of matching only the "OK" string. I will try to figure it out. Many thanks!
  • hoolio's avatar
    hoolio
    Icon for Cirrostratus rankCirrostratus
    Jun 16, 2011
    Actually, it looks like you can't use a negative lookbehind in a monitor receive string. There are a few other options:

     

     

    use a receive string of \r\nOK

     

    change the app to return a unique string like DOWN instead of NOTOK

     

     

    Aaron
  • Daniel_55334's avatar
    Daniel_55334
    Icon for Altostratus rankAltostratus
    Jun 16, 2011
    Hi hoolio,

     

     

    I tried "^OK$" which I assume is the exact match of the string "OK". But then the member is marked down. Is the regex wrong?
  • Daniel_55334's avatar
    Daniel_55334
    Icon for Altostratus rankAltostratus
    Jun 16, 2011
    Hi nitass,

     

     

    Your suggestion works for all string that starts with "OK", e.g. OKOK

     

    How can I make it only to match "OK"?
  • hoolio's avatar
    hoolio
    Icon for Cirrostratus rankCirrostratus
    Jun 16, 2011
    Were you able to try a receive string of:

     

     

    \r\nOK

     

     

    If that doesn't work, can you try:

     

     

    \x0d\x0aOK

     

     

    sol4186: Entering escape sequences in an ECV health monitor's send and receive strings

     

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

     

     

    Aaron
  • Daniel_55334's avatar
    Daniel_55334
    Icon for Altostratus rankAltostratus
    Jun 16, 2011
    Hi Aaron,

     

     

    Both of them do not work. The member is marked as down. However as I am at home now so I can only test it with VE which is 10.1.0. Not sure if that matters.
  • nitass's avatar
    nitass
    Icon for Employee rankEmployee
    Jun 18, 2011
    i think i know what is wrong. ok is also in http header i.e. http status code

     

     

    curl -i http://10.10.70.110/monitor1.html

     

    HTTP/1.1 200 OK

     

    Date: Fri, 17 Jun 2011 19:29:21 GMT

     

    Server: Apache/2.0.59 (rPath)

     

    Last-Modified: Fri, 17 Jun 2011 19:21:47 GMT

     

    ETag: "6696-4-4bf4a8c0"

     

    Accept-Ranges: bytes

     

    Content-Length: 4

     

    Vary: Accept-Encoding

     

    Content-Type: text/html; charset=UTF-8

     

     

    ABC

     

     

    curl -i http://10.10.70.110/monitor2.html

     

    HTTP/1.1 200 OK

     

    Date: Fri, 17 Jun 2011 19:29:32 GMT

     

    Server: Apache/2.0.59 (rPath)

     

    Last-Modified: Fri, 17 Jun 2011 19:22:41 GMT

     

    ETag: "6693-7-4f2ca240"

     

    Accept-Ranges: bytes

     

    Content-Length: 7

     

    Vary: Accept-Encoding

     

    Content-Type: text/html; charset=UTF-8

     

     

    NOTABC

     

     

    curl -i http://10.10.70.110/monitor3.html

     

    HTTP/1.1 200 OK

     

    Date: Fri, 17 Jun 2011 19:29:47 GMT

     

    Server: Apache/2.0.59 (rPath)

     

    Last-Modified: Fri, 17 Jun 2011 19:22:51 GMT

     

    ETag: "65bb-7-4fc538c0"

     

    Accept-Ranges: bytes

     

    Content-Length: 7

     

    Vary: Accept-Encoding

     

    Content-Type: text/html; charset=UTF-8

     

     

    ABCABC

     

     

    [root@tulip:Active] config b monitor myhttp list

     

    monitor myhttp {

     

    defaults from http

     

    interval 2

     

    timeout 7

     

    recv "(.*)^abc\n"

     

    send "GET /monitor1.html HTTP/1.1\r\nHost: \r\nConnection: Close\r\n\r\n"

     

    }

     

    [root@tulip:Active] config b pool pooh list

     

    pool pooh {

     

    monitor all myhttp

     

    members 10.10.70.110:http {}

     

    }

     

    [root@tulip:Active] config b pool pooh

     

    POOL pooh LB METHOD round robin MIN/CUR ACTIVE MEMBERS 0/1

     

    | (cur, max, limit, tot) = (0, 0, 0, 0)

     

    | (pkts,bits) in = (0, 0), out = (0, 0)

     

    +-> POOL MEMBER pooh/10.10.70.110:http active,up

     

    | session enabled priority 0 ratio 1

     

    | (cur, max, limit, tot) = (0, 0, 0, 0)

     

    | (pkts,bits) in = (0, 0), out = (0, 0)

     

    | requests (total) = 0

     

     

    [root@tulip:Active] config b monitor myhttp list

     

    monitor myhttp {

     

    defaults from http

     

    interval 2

     

    timeout 7

     

    recv "(.*)^abc\n"

     

    send "GET /monitor2.html HTTP/1.1\r\nHost: \r\nConnection: Close\r\n\r\n"

     

    }

     

    [root@tulip:Active] config b pool pooh

     

    POOL pooh LB METHOD round robin MIN/CUR ACTIVE MEMBERS 0/0

     

    | (cur, max, limit, tot) = (0, 0, 0, 0)

     

    | (pkts,bits) in = (0, 0), out = (0, 0)

     

    +-> POOL MEMBER pooh/10.10.70.110:http inactive,down

     

    | session enabled priority 0 ratio 1

     

    | (cur, max, limit, tot) = (0, 0, 0, 0)

     

    | (pkts,bits) in = (0, 0), out = (0, 0)

     

    | requests (total) = 0

     

     

    [root@tulip:Active] config b monitor myhttp list

     

    monitor myhttp {

     

    defaults from http

     

    interval 2

     

    timeout 7

     

    recv "(.*)^abc\n"

     

    send "GET /monitor3.html HTTP/1.1\r\nHost: \r\nConnection: Close\r\n\r\n"

     

    }

     

    [root@tulip:Active] config b pool pooh

     

    POOL pooh LB METHOD round robin MIN/CUR ACTIVE MEMBERS 0/0

     

    | (cur, max, limit, tot) = (0, 0, 0, 0)

     

    | (pkts,bits) in = (0, 0), out = (0, 0)

     

    +-> POOL MEMBER pooh/10.10.70.110:http inactive,down

     

    | session enabled priority 0 ratio 1

     

    | (cur, max, limit, tot) = (0, 0, 0, 0)

     

    | (pkts,bits) in = (0, 0), out = (0, 0)

     

    | requests (total) = 0