Elegant way to run an aggregate ext test over multiple clients?
list Elizabeth Schwartz
Suppose I have a five-server cluster, and on each server there's a
calculated value, call it Q, and an ext test "qlength" that operates
on Q and returns a color and a message containing Q.
We want to make a server-side test that does some alerting based on
aggregate values of Q across all five servers in the cluster. Not a
combo test, we want to do math, like Sum (Q1...Qn) >Threshold.
*One* way to get Q for each server is to write a server-side ext test
that loops a wget over each host, something like:
wget /dev/null
http://xymon/xymon-cgi/svcstatus.sh\?HOST=myhost.example.com\&SERVICE=qlength
then parse each server's Q info out of the html and do my arithmetic,
but is there a more direct way?
thanks for any pointers clues or code snippets
Betsy
list Vernon Everett
That's probably how I would do it.
I have done something similar to this before, but I no longer have
access to the code.
You need to get all the values together in one script, and grabbing
the web page is a pretty quick and easy way to do so.
A command you may find useful, is this
sed -e :a -e 's/<[^>]*>//g;/</N;//ba'
It will strip most HTML tags, making parsing a lot easier.
However, if Q is being graphed, it will already be on a line by
itself, so you may be able to simply
grep "^Q=[1-9][0-9]*$"
or
grep "^Q:[1-9][0-9]*$"
Depending on how your scripts send the data.
Hope it works..
Vernon
On Wed, May 18, 2011 at 9:32 AM, Elizabeth Schwartz
▸
<user-c61747246f66@xymon.invalid> wrote:Suppose I have a five-server cluster, and on each server there's a calculated value, call it Q, and an ext test "qlength" that operates on Q and returns a color and a message containing Q. We want to make a server-side test that does some alerting based on aggregate values of Q across all five servers in the cluster. Not a combo test, we want to do math, like Sum (Q1...Qn) >Threshold. *One* way to get Q for each server is to write a server-side ext test that loops a wget over each host, something like: wget /dev/null http://xymon/xymon-cgi/svcstatus.sh\?HOST=myhost.example.com\&SERVICE=qlength then parse each server's Q info out of the html and do my arithmetic, but is there a more direct way? thanks for any pointers clues or code snippets Betsy
list Jason Kincl
Another option could be to send your Q message as a "data" message instead of a "status" message, then set up a xymon_channel on the server that listens for data messages and when you see your Q data message come along, to do the calculations and report a single status back to xymon. The webpage scraping is probably easier though, but I just thought of it and wanted to bounce the idea.
▸
On May 17, 2011, at 8:56 PM, Vernon Everett wrote:
That's probably how I would do it. I have done something similar to this before, but I no longer have access to the code. You need to get all the values together in one script, and grabbing the web page is a pretty quick and easy way to do so. A command you may find useful, is this sed -e :a -e 's/<[^>]*>//g;/</N;//ba' It will strip most HTML tags, making parsing a lot easier. However, if Q is being graphed, it will already be on a line by itself, so you may be able to simply grep "^Q=[1-9][0-9]*$" or grep "^Q:[1-9][0-9]*$" Depending on how your scripts send the data. Hope it works.. Vernon On Wed, May 18, 2011 at 9:32 AM, Elizabeth Schwartz <user-c61747246f66@xymon.invalid> wrote:Suppose I have a five-server cluster, and on each server there's a calculated value, call it Q, and an ext test "qlength" that operates on Q and returns a color and a message containing Q. We want to make a server-side test that does some alerting based on aggregate values of Q across all five servers in the cluster. Not a combo test, we want to do math, like Sum (Q1...Qn) >Threshold. *One* way to get Q for each server is to write a server-side ext test that loops a wget over each host, something like: wget /dev/null http://xymon/xymon-cgi/svcstatus.sh\?HOST=myhost.example.com\&SERVICE=qlength then parse each server's Q info out of the html and do my arithmetic, but is there a more direct way? thanks for any pointers clues or code snippets Betsy
Jason
list David W Gore
My solution, which I have implemented for quite a number of tests, is to
do something similar to what xymon already does which is to use the
xymon message client file.
For instance add a section to hobbitclient-sunos.sh, Solaris client used
as an example:
echo [Qdata]
cat my/q_file_results.txt # be careful what you do here if it is a
script or something that can potentially hang the client look at the
vmstat and iostat lines
From the server:
Using PERL as an example scripting language:
foreach my $host ( @hostList )
{
@qData = `path2/bin/xymon localhost "clientlog $host
section=Qdata"`;
}
Here is an example from the command line:
xymon at xymon1> ~/server/bin/xymon localhost "clientlog xymon1
section=who"
[xymon at xymon1 all]$ ~/server/bin/xymon localhost "clientlog xymon1
section=who"
[who]
xymon pts/0 May 18 22:48 (10.2.3.4)
Just make your own section on all the clients in the
hobbitclient-[OS].sh script.
~David
-----Original Message-----
From: xymon-bounces at xymon.com [mailto:xymon-bounces at xymon.com] On Behalf
Of Jason Kincl
Sent: Wednesday, May 18, 2011 12:46
To: Xymon
Subject: Re: [Xymon] Elegant way to run an aggregate ext test over
multipleclients?
▸
Another option could be to send your Q message as a "data" message
instead of a "status" message, then set up a xymon_channel on the server
that listens for data messages and when you see your Q data message come
along, to do the calculations and report a single status back to xymon.
The webpage scraping is probably easier though, but I just thought of it
and wanted to bounce the idea.
On May 17, 2011, at 8:56 PM, Vernon Everett wrote:
That's probably how I would do it. I have done something similar to this before, but I no longer have access to the code. You need to get all the values together in one script, and grabbing the web page is a pretty quick and easy way to do so. A command you may find useful, is this sed -e :a -e 's/<[^>]*>//g;/</N;//ba' It will strip most HTML tags, making parsing a lot easier. However, if Q is being graphed, it will already be on a line by itself, so you may be able to simply grep "^Q=[1-9][0-9]*$" or grep "^Q:[1-9][0-9]*$" Depending on how your scripts send the data. Hope it works.. Vernon On Wed, May 18, 2011 at 9:32 AM, Elizabeth Schwartz <user-c61747246f66@xymon.invalid> wrote:Suppose I have a five-server cluster, and on each server there's a calculated value, call it Q, and an ext test "qlength" that operates on Q and returns a color and a message containing Q. We want to make a server-side test that does some alerting based on aggregate values of Q across all five servers in the cluster. Not a combo test, we want to do math, like Sum (Q1...Qn) >Threshold. *One* way to get Q for each server is to write a server-side ext test that loops a wget over each host, something like: wget /dev/null
http://xymon/xymon-cgi/svcstatus.sh\?HOST=myhost.example.com\&SERVICE=ql ength
▸
then parse each server's Q info out of the html and do my arithmetic, but is there a more direct way? thanks for any pointers clues or code snippets Betsy
Jason