Re: Service monitoring

> Here's a part of the output from "ps -ef" showing the
> three methods Piranha uses to check ports/services.

ps -ef won't show you the full command line, and that must be why your
following explanations are wrong ! Try pas auxww instead !

> The first is the explicit use of a shell script (such as one that
> telnets to the port),
> /usr/sbin/nanny -c -h 134.126.12.41 -p 23 -e
> /etc/sysconfig/ha/test_smtp.sh root

Right, despite the fact a few mandatory options are missing

> the second is a string of chars specified to be sent to the port
> (usually http only)
> /usr/sbin/nanny -c -h 134.126.12.41 -p 23 -e
> /etc/sysconfig/ha/test_smtp.sh root

Same comment. Plus : full text send/expect strings is not "reserved" to
http, it can be use for any text based protocal (POP, IMAP, SMTP, HTTP,
FTP, etc).

> and the third is the default if you do not specify any test method

So far, you're right

> then IPVSADM is used by Piranha:
> /usr/sbin/nanny -c -h 134.126.12.41 -p 443 -a 15 -I
> /sbin/ipvsadm -t 6

But this is your main mistake. Check nanny --help !
-I only specifies the location of ipvsadm, it does not and cannot
replace -e/-s/-x

In your example, you're just showing a nanny that doesn't either have a
send string not a send program. In this special case, nanny will just
try to connect to the appropriate port and disconnect if it succeed.
Health *checking* (the action of guessing if the RS is working or not)
has nothing to do with IPVS. But, once it's done, and depending on the
previous state of the tested RS, nanny can decide to alter the
shceduling table using ipvsadm. Hope it's clear :)

> You are best off doing a "man ipvsadm" to check out
> its options.

Nop ! man nanny !

> Right.  The default gateway on the real server SHOULD
> BE SET TO the NAT IP ADDRESS of the Piranha server.

No, he said he's using DR, so the DGW on RS is the usual DGW for the
network they belong to. If he wants to route back through the director,
he'll have to enable log_martians (AFAIR).

-- 
Sébastien Bonnet
  Centre de contacts - Experian France