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Stupid sound question - "DNS Error"

10 messages in this thread

list Gary Baluha · Wed, 5 Sep 2007 09:43:32 -0400 · 
It sounds like an obvious answer, but what does the http/https monitoring
error "DNS Error" mean, exactly?

Specifically, I have several https checks defined in Hobbit, and a good
number of them get the "DNS Error" message multiple times a day; roughly on
the order of every 1-3 hours.  I have manually verified that DNS is working
for these hosts.  It might help me troubleshoot this if I know exactly how
Hobbit comes to this determination, and if anything else other than DNS
could cause it to appear.
list Charles Goyard · Wed, 5 Sep 2007 15:52:45 +0200 ·
▸ quoted from Gary Baluha
Gary Baluha wrote :
It sounds like an obvious answer, but what does the http/https monitoring
error "DNS Error" mean, exactly?
I advise you to install a local DNS cache server: it makes things a lot
better, especially for http.


-- 
Charles Goyard - user-a6cdca7046e2@xymon.invalid - (+33) 1 45 38 01 31
Orange Business Services - online multimedia  // ingénierie
list Henrik Størner · Wed, 5 Sep 2007 17:11:52 +0200 ·
▸ quoted from Gary Baluha
On Wed, Sep 05, 2007 at 09:43:32AM -0400, Gary Baluha wrote:
It sounds like an obvious answer, but what does the http/https monitoring
error "DNS Error" mean, exactly?
It means Hobbit could not lookup the hostname in DNS.
▸ quoted from Gary Baluha
Specifically, I have several https checks defined in Hobbit, and a good
number of them get the "DNS Error" message multiple times a day; roughly on
the order of every 1-3 hours.  I have manually verified that DNS is working
for these hosts.  It might help me troubleshoot this if I know exactly how
Hobbit comes to this determination, and if anything else other than DNS
could cause it to appear.
A local caching DNS server is usually a good idea. Hobbit has been known
to knock out DNS servers, because it sends a lot of requests very
quickly.


Regards,
Henrik
list Gary Baluha · Wed, 5 Sep 2007 11:45:08 -0400 ·
▸ quoted from Henrik Størner
On 9/5/07, Henrik Stoerner <user-ce4a2c883f75@xymon.invalid> wrote:
On Wed, Sep 05, 2007 at 09:43:32AM -0400, Gary Baluha wrote:
It sounds like an obvious answer, but what does the http/https
monitoring
error "DNS Error" mean, exactly?
It means Hobbit could not lookup the hostname in DNS.

Okay, I thought it was pretty self explanatory, but a quick glance at the
code wasn't obvious to me.
▸ quoted from Henrik Størner
Specifically, I have several https checks defined in Hobbit, and a good
number of them get the "DNS Error" message multiple times a day; roughly
on
the order of every 1-3 hours.  I have manually verified that DNS is
working
for these hosts.  It might help me troubleshoot this if I know exactly
how
Hobbit comes to this determination, and if anything else other than DNS
could cause it to appear.
A local caching DNS server is usually a good idea. Hobbit has been known
to knock out DNS servers, because it sends a lot of requests very
quickly.

Well, two suggestions to have a local caching DNS must mean it's a pretty
good idea.  I set this up, and will see if that fixes the problem.
list Gary Baluha · Wed, 5 Sep 2007 13:15:50 -0400 · 
It seems adding a local caching DNS server did no fix this problem.  I'm
truely at a loss now, because nothing I test manually seems to indicate a
problem.  Also, when the hobbit alerts go red due to "DNS Error", as soon as
I go to check, it has cleared up already.
▸ quoted from Gary Baluha

On 9/5/07, Gary Baluha <user-ae3e15c22de1@xymon.invalid> wrote:
On 9/5/07, Henrik Stoerner <user-ce4a2c883f75@xymon.invalid> wrote:
On Wed, Sep 05, 2007 at 09:43:32AM -0400, Gary Baluha wrote:
It sounds like an obvious answer, but what does the http/https
monitoring
error "DNS Error" mean, exactly?
It means Hobbit could not lookup the hostname in DNS.

Okay, I thought it was pretty self explanatory, but a quick glance at the
code wasn't obvious to me.

Specifically, I have several https checks defined in Hobbit, and a good
number of them get the "DNS Error" message multiple times a day;
roughly on
the order of every 1-3 hours.  I have manually verified that DNS is
working
for these hosts.  It might help me troubleshoot this if I know exactly
how
Hobbit comes to this determination, and if anything else other than
DNS
could cause it to appear.
A local caching DNS server is usually a good idea. Hobbit has been known

to knock out DNS servers, because it sends a lot of requests very
quickly.

Well, two suggestions to have a local caching DNS must mean it's a pretty
good idea.  I set this up, and will see if that fixes the problem.
list Henrik Størner · Wed, 5 Sep 2007 22:47:26 +0200 · 
Try increasing the timeout setting on the network tests - add a
"--timeout=30" option to the bbtest-net command in hobbitlaunch.cfg .

Regards,
Henrik
▸ quoted from Gary Baluha

On Wed, Sep 05, 2007 at 01:15:50PM -0400, Gary Baluha wrote:
It seems adding a local caching DNS server did no fix this problem.  I'm
truely at a loss now, because nothing I test manually seems to indicate a
problem.  Also, when the hobbit alerts go red due to "DNS Error", as soon as
I go to check, it has cleared up already.

On 9/5/07, Gary Baluha <user-ae3e15c22de1@xymon.invalid> wrote:
On 9/5/07, Henrik Stoerner <user-ce4a2c883f75@xymon.invalid> wrote:
On Wed, Sep 05, 2007 at 09:43:32AM -0400, Gary Baluha wrote:
It sounds like an obvious answer, but what does the http/https
monitoring
error "DNS Error" mean, exactly?
It means Hobbit could not lookup the hostname in DNS.

Okay, I thought it was pretty self explanatory, but a quick glance at the
code wasn't obvious to me.

Specifically, I have several https checks defined in Hobbit, and a good
number of them get the "DNS Error" message multiple times a day;
roughly on
the order of every 1-3 hours.  I have manually verified that DNS is
working
for these hosts.  It might help me troubleshoot this if I know exactly
how
Hobbit comes to this determination, and if anything else other than
DNS
could cause it to appear.
A local caching DNS server is usually a good idea. Hobbit has been known

to knock out DNS servers, because it sends a lot of requests very
quickly.

Well, two suggestions to have a local caching DNS must mean it's a pretty
good idea.  I set this up, and will see if that fixes the problem.


-- 

Henrik Storner
list Frank Flynn · Wed, 5 Sep 2007 16:01:48 -0700 · 
I have a simple shell script which I want to use as a client plugin.   In the script I create the STATUS and some other messages that I want  to use and assemble them into a CMD.

But bb will not accept this from the script - but the command is  perfect - I can say that because to debug I echo the command and if I  copy and paste it works.  But if have the script run the $CMD it fails.

In the script:
MYCMD="$BB $BBDISP \"status $MACHINE.BWEB $STATUS `date` WEB OK\""

echo $MYCMD

$MYCMD

I run it from inside of bbcmd and I get:

sh-3.1$ ext/webCheck.sh
/home/hobbit/client/bin/bb 10.1.90.21 "status  web2,sc1,boredat,net.BWEB green Wed Sep 5 14:55:08 PDT 2007 WEB OK"
Hobbit version 4.2.0
Usage: /home/hobbit/client/bin/bb [--debug] [--proxy=http:// ip.of.the.proxy:port/] RECIPIENT DATA
   RECIPIENT: IP-address, hostname or URL
   DATA: Message to send, or "-" to read from stdin
sh-3.1$

And if I copy and paste the first line - it works, the server sees it  and everything is fine.
list Frank Flynn · Wed, 5 Sep 2007 17:15:39 -0700 · 
OK well I found a work around,

If I break it into two in the script and pass the data to bb through  stdin this will work
----
MYCMD="$BB $BBDISP -"

echo "status $MACHINE.Bd@ $STATUS `date` local web check" | $MYCMD
----

This works for me - but is there a better way?

Thanks,
Frank
▸ quoted from Frank Flynn

On Sep 5, 2007, at 4:01 PM, Frank Flynn wrote:

I have a simple shell script which I want to use as a client  plugin.  In the script I create the STATUS and some other messages  that I want to use and assemble them into a CMD.

But bb will not accept this from the script - but the command is  perfect - I can say that because to debug I echo the command and if  I copy and paste it works.  But if have the script run the $CMD it  fails.

In the script:
MYCMD="$BB $BBDISP \"status $MACHINE.BWEB $STATUS `date` WEB OK\""

echo $MYCMD

$MYCMD

I run it from inside of bbcmd and I get:

sh-3.1$ ext/webCheck.sh
/home/hobbit/client/bin/bb 10.1.90.21 "status  web2,sc1,boredat,net.BWEB green Wed Sep 5 14:55:08 PDT 2007 WEB OK"
Hobbit version 4.2.0
Usage: /home/hobbit/client/bin/bb [--debug] [--proxy=http:// ip.of.the.proxy:port/] RECIPIENT DATA
  RECIPIENT: IP-address, hostname or URL
  DATA: Message to send, or "-" to read from stdin
sh-3.1$

And if I copy and paste the first line - it works, the server sees  it and everything is fine.
list Ralph Mitchell · Wed, 5 Sep 2007 22:30:49 -0500 ·
▸ quoted from Frank Flynn
On 9/5/07, Frank Flynn <user-32aefea160e6@xymon.invalid> wrote:
OK well I found a work around,

If I break it into two in the script and pass the data to bb through
stdin this will work
----
MYCMD="$BB $BBDISP -"

echo "status $MACHINE.Bd@ $STATUS `date` local web check" | $MYCMD
----

This works for me - but is there a better way?
Why not something like this:

     MESSAGE="status $MACHINE.Bd@ $STATUS `date` local web check"
     $BB $BBDISP "$MESSAGE"

Ralph Mitchell
list Gary Baluha · Thu, 6 Sep 2007 09:54:10 -0400 · 
Actually, it seems I just didn't allow enough time for the caching DNS
server to actually cache...
That does seem to have fixed the "DNS Error" problem.  But I will keep your
suggestion in mind in case it comes back.

Thanks for the suggestions everyone.
▸ quoted from Henrik Størner

On 9/5/07, Henrik Stoerner <user-ce4a2c883f75@xymon.invalid> wrote:
Try increasing the timeout setting on the network tests - add a
"--timeout=30" option to the bbtest-net command in hobbitlaunch.cfg .

Regards,
Henrik

On Wed, Sep 05, 2007 at 01:15:50PM -0400, Gary Baluha wrote:
It seems adding a local caching DNS server did no fix this problem.  I'm
truely at a loss now, because nothing I test manually seems to indicate
a
problem.  Also, when the hobbit alerts go red due to "DNS Error", as
soon as
I go to check, it has cleared up already.

On 9/5/07, Gary Baluha <user-ae3e15c22de1@xymon.invalid> wrote:
On 9/5/07, Henrik Stoerner <user-ce4a2c883f75@xymon.invalid> wrote:
On Wed, Sep 05, 2007 at 09:43:32AM -0400, Gary Baluha wrote:
It sounds like an obvious answer, but what does the http/https
monitoring
error "DNS Error" mean, exactly?
It means Hobbit could not lookup the hostname in DNS.

Okay, I thought it was pretty self explanatory, but a quick glance at
the
code wasn't obvious to me.

Specifically, I have several https checks defined in Hobbit, and a
good
number of them get the "DNS Error" message multiple times a day;
roughly on
the order of every 1-3 hours.  I have manually verified that DNS
is
working
for these hosts.  It might help me troubleshoot this if I know
exactly
how
Hobbit comes to this determination, and if anything else other
than
DNS
could cause it to appear.
A local caching DNS server is usually a good idea. Hobbit has been
known

to knock out DNS servers, because it sends a lot of requests very
quickly.

Well, two suggestions to have a local caching DNS must mean it's a
pretty
good idea.  I set this up, and will see if that fixes the problem.


--
Henrik Storner