Issue with "HTTP Monitor cURL Probe Timeout" - and question about timeout options

Hello -

 

This is a 2-part question/issue regarding the "HTTP Monitor cURL Probe Timeout" monitor outline here: https://devcentral.f5.com/wiki/advd...meout.ashx

 

The first issue is that my nodes are always being marked up regardless of what I have defined in the "RECV" variable. As a test - I defined the variable with the text string "thisshouldfail" - and the nodes continue to stay online.

 

Second - I need to be able to specify the timeout value (P_TIMEOUT) in milliseconds - but the standard curl "-m" command will only accept seconds. Are there any modifications I can make to this method that would allow me to specify that value in milliseconds? Our application is extremely sensitive to timeouts - so I need to set that to something around 150-200 ms.

 

The actual configuration and "external monitor file" I'm using are below. Note that I had to modify the curl request from the original file to add the Host header value in order for the request to work with our servers (--header "Host:example.companyname.com"). I have also substituted some of the values in the URI string to protect company data.

 

Any advice or suggestions would be greatly appriciated! :-)

 

Thanks!

 

==================================================================

 

ltm monitor external /Common/AdServe_curl_timeout_v2 {

 

defaults-from /Common/external

 

destination *:*

 

interval 5

 

run /Common/http_probe_with_timeout

 

time-until-up 0

 

timeout 16

 

user-defined POOL server_pool1

 

user-defined P_TIMEOUT 2

 

user-defined RECV thisshouldfail

 

user-defined URI /hic/\?arg1=something&arg2=300&arg3=250&arg4=160&arg5=soemthingelse&arg6=string5&nb&passback&random

 

}

 

==================================================================

 

 

!/bin/sh

 

 

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users of the program, for instance in the event that we extend our services

 

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@() $Id: HTTPMonitor_cURL_ProbeTimeout,v 1.0 2007/09/20 13:09:07 deb Exp $

 

(based on sample_monitor,v 1.3 2005/02/04 18:47:17 saxon)

 

 

 

 

these arguments supplied automatically for all external monitors:

 

$1 = IP (nnn.nnn.nnn.nnn notation)

 

$2 = port (decimal, host byte order)

 

 

additional command line arguments ($3 and higher) may be specified in the monitor template

 

(This example does not expect any additional command line arguments)

 

 

Name/Value pairs may also be specified in the monitor template

 

This example expects the following Name/Vaule pairs:

 

P_TIMEOUT = the probe timeout value -- max time for app to respond to be marked UP

 

POOL = the name of the pool containing the members monitored by this monitor instance

 

URI = the URI to request from the server

 

RECV = the expected response (not case sensitive)

 

 

 

remove IPv6/IPv4 compatibility prefix (LTM passes addresses in IPv6 format)

 

IP=`echo ${1} | sed 's/::ffff://'`

 

PORT=${2}

 

 

PIDFILE="/var/run/`basename ${0}`.${IP}_${PORT}.pid"

 

kill of the last instance of this monitor if hung and log current pid

 

if [ -f $PIDFILE ]

 

then

 

kill -9 `cat $PIDFILE` > /dev/null 2>&1

 

fi

 

echo "$$" > $PIDFILE

 

 

send request & check for expected response

 

curl -fNs -m ${P_TIMEOUT} --header "Host:example.companyname.com" http://${IP}:${PORT}${URI} | grep -i "${RECV}" 2>&1 > /dev/null

 

 

if expected response was received, force the node UP if it was previously

 

FORCEDOWN, & output something to stdout so bigd continues to mark the node UP

 

if [ $? -eq 0 ]

 

then

 

/bin/bigpipe pool myPool member 10.10.10.100:8080 show | grep "forced down" 2>&1 > /dev/null

 

if [ $? -eq 0 ]

 

then

 

/bin/bigpipe pool ${POOL} member ${IP}:${PORT} up 2>&1 > /dev/null

 

fi

 

rm -f $PIDFILE

 

echo "UP"

 

if expected response is not received in time, force the node DOWN immediately

 

else

 

/bin/bigpipe pool ${POOL} member ${IP}:${PORT} down 2>&1 > /dev/null

 

rm -f $PIDFILE

 

exit

 

fi