HTTPMonitor_cURL_ProbeTimeout

The Adv Design & Config "ExternalMonitor" wiki page (Click here) has the implementation details you're looking for.

 

 

/deb

The directions say to put it in /config/eav but the F5 insists it be in /usr/bin/monitors

 

Once I put the script there

 

I added the following name/value variables in the GUI

 

CAUCHOPORT=4000

 

POOL=cwmp.stage.443

 

URI=/caucho-status

 

P_TIMEOUT=5

 

and the following argument

 

curl -fNs -m ${P_TIMEOUT} http://w50-$i.c50.2wire.com

 

 

I set the alias service port to 4000

 

 

I changed the script to match the F5 example here

 

then

 

echo "UP"

 

else

 

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

 

fi

 

but it makes no difference

 

The members are shown as red and down

 

Not sure what I am dong wrong

 

OK, wiki page is updated to indicate the correct directory, sorry for the confusion there.

 

 

Now as far as your variables are concerned, you need either set them in the monitor definition as name/value pairs OR set them within the script. If you do both, your monitor settings will be ignored and the script values will be used for every instance of the script. In this case, since they are the same, that isn't the problem. (Also, if your pool members are defined on port 4000 already, you don't need to specify that as a variable value in either place.)

 

 

I'm not sure I understand your intention regarding the argument you've specified, but since your script doesn't look for any arguments (passed as $3 or greater), eliminate all arguments from the monitor definition.

 

 

LTM by default isn't configured for name resolution, and even if it were, resolving a name within a monitor is not recommended since the induced latency will most likely result in intermittent false down's.

 

 

You also have not included the required LTMv9 IP address parsing line. (This is the most likely reason your monitor is failing -- no valid destination address. I bet if you looked at a trace, you'd see no monitor traffic.)

 

 

I didn't notice reading your script before, but it seems to be using a for loop to check both pool members, and the loop is terminated in the wrong place for proper pidfile management. You are also using a bigpipe command to manipulate the node status. Neither approach represents how LTM monitors are intended to work, and both of them will interfere with the normal operation of the monitor.

 

 

Hold on & I'll post a script that will work and the monitor definition to deploy it...

 

 

/deb

OK...

Assuming your pool members are listening for monitor traffic on the same port as load balanced traffic, use this script:

 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 ${P_TIMEOUT} http://${IP}:${PORT}${URI} | grep -i "${RECV}" 2>&1 > /dev/null
 let bigd mark node UP if expected response was received
 otherwise force the node DOWN immediately
if [ $? -eq 0 ]
then
    echo "UP"
else
    /bin/bigpipe pool ${POOL} member ${IP}:${PORT} down 2>&1 > /dev/null
fi
rm -f $PIDFILE
exit

And configure your monitor with these variables:

RECV=w50-[12].c50.domain.com:6802 .ok.
POOL=cwmp.stage.443
URI=/caucho-status
P_TIMEOUT=5

HTH

/deb

The script above did not work

 

I added CAUCHOPORT=4000 to the GUI template

 

and added

 

curl -fNs -m ${P_TIMEOUT} http://${IP}:${CAUCHOPORT}${URI} | grep -i "${RECV}" 2>&1 > /dev/null

 

but it still did not work

 

the reason being is that I need the F5 to check the resin status page at port 4000.

 

Resin handles the db connections on the back end.

 

Each app server hosts a page called resin status page (this page is only for monitoring)

 

This is located at IPADDRESS:4000/caucho-status

 

I need to grep each app servers resin status page for w50-1.c50.domain.com:6802 (ok) for app server 1

 

I need to grep the applicable page for w50-2c50.domain.com:6802 (ok) for app server 2

 

the pool cwmp.stage.443 actually sends traffic to port 5004 not 4000

 

but it still did not work

 

 

 

 

the pool cwmp.stage.443 actually sends to 5004

 

so when it downs the member traffice should not go to this port

Then you would want to use the supplied script and define the monitor template with the alias port of 4000, and it will pass it to the monitor as $2 / $PORT, rather than adding yet another variable with the same value.

 

 

/deb

 

Whether I put the 4000 in the GUI template or the script it still marks all servers as down.

 

I am not sure why

 

the script in my original post should work fine if the monitor can detect the UP per member

 

Your original script might work fine as a standalone, but if you are going to run it as a monitor, there are some special considerations you must take into account when coding. Review my first response for details.

 

 

If you could please post the bigip.conf sections for the virtual server, the pool, and the monitor definitions, I may be able to help further.

 

 

/deb

Attached is the monitor pool and virtual server configs

 

It does not matter if the monitor is applied to the pool cwmp.stage.443 or cwmp.stage.80

 

10.50.1.3 w50-3 and 10.50.1.4 w50-4 are offline for other reasons

 

}

 

monitor curlcaucho {

 

defaults from external

 

dest *:4000

 

POOL "cwmp.stage.443"

 

P_TIMEOUT "5"

 

RECV "w50-[12].c50.domain.com:6802 .ok."

 

run "curlcaucho"

 

URI "/caucho-status"

 

}

 

 

virtual cwmp.stage.443 {

 

destination 216.52.22.101:https

 

ip protocol tcp

 

profile cwmp.stage tcp

 

pool cwmp.stage.80

 

}

 

 

pool cwmp.stage.443 {

 

lb method member least conn

 

monitor all http and curlcaucho

 

member 10.50.1.1:5004

 

member 10.50.1.2:5004

 

member 10.50.1.3:5004

 

member 10.50.1.4:5004

 

}

 

 

 

 

sample html resin-status page to be parsed

 

 

resin-status

 

 

 

Server: w50-1.c50.domain.com

 

Config: /var/cms/conf/resin.conf

 

Server Start: Wed, 12 Dec 2007 14:28:23 -0800 (PST)

 

Server Reload: Wed, 12 Dec 2007 14:28:23 -0800 (PST)

 

Total Memory: 769.26Meg

 

Free Memory: 32.08Meg

 

 

TCP ports

 

 

Current Threads Config

 

Protocolort Active Keepalive Total thread-max keepalive-max request-timeout

 

srun:6802 1 0 6 200 100 65

 

http:8080 1 0 3 200 100 65

 

 

Srun Servers

 

 

 

Host Active Count live-time dead-time request-timeout

 

1. w50-1.c50.domain.com:6802 (ok) 0 15 15 30

 

2. w50-2.c50.domain.com:6802 (ok) 0 15 15 30

 

The script and monitor definition look fine, unless your servers are expecting an HTTPS request.

 

 

I see you have 2 monitors applied - the external monitor we've been discusssing + the default http monitor. I'd start by removing the default http monitor until I got the other working, then decide if it's even necessary.

 

 

If the external monitor by itself is still is marking the pool members down, you'll need to capture a packet trace from the server vlan, filtering on the LTM non-floating self-IP and port 4000, and look for monitor traffic from LTM to the servers & back.

 

 

HTH

 

/deb