Re: [Ganglia-developers] Thoughts on host spoofing
>>> On 2/5/2009 at 11:36 PM, in message , Spike Spiegel wrote: > Hi, > > thanks for the clarification, > > On Thu, Feb 5, 2009 at 11:44 PM, Brad Nicholes wrote: > >> Anything else the spoofing module needs to do beyond this >> it completely up to the module developer. Any or all of what you >> described below should just be module implementation details. > > Ok, so given that's the way forward as far as coding something goes, > how does upstream folks feel about a patch to all the C modules to use > spoofing based on a config parameter? Because that's what I need in > order to solve my PTR problems and I wouldn't want to have to redo all > of them in python, but on the other side if a patch wouldn't be The main problem with doing what you described above isn't with creating the spoofing metric definition. That part would be easy. The real problem is with gathering the metric data. Gathering CPU utilization metrics from a local box, for example, is completely different than gather the cpu_util from a remote box and even different than gathering it from a virtual machine. That is the main reason why special spoofing modules are necessary rather than simply tweaking the modules that we have already. > accepted I might consider it. On a side note, has anybody done an > estimation of the performance hit between a python and C module? > I have done a little testing in this area. Since gather metrics is on the order of seconds, speed performance between a C module and a python module isn't an issue. Memory footprint is really the main difference between the two. Obviously loading mod_python and running python modules is going to increase the memory footprint of gmond. If I run gmond with just the C modules installed, the memory footprint of gmond is somewhere under 1 mb. If I load mod_python and start to run some of the python metric modules, the memory footprint jumps between 1.5 and 3 mb. Obviously the more metric modules you run, whether they are C or python, is going to increase the memory footprint also. Brad -- Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM) software. With Adobe AIR, Ajax developers can use existing skills and code to build responsive, highly engaging applications that combine the power of local resources and data with the reach of the web. Download the Adobe AIR SDK and Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com ___ Ganglia-developers mailing list Ganglia-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ganglia-developers
Re: [Ganglia-developers] Thoughts on host spoofing
>>> On 2/5/2009 at 11:52 PM, in message , >>> Rick Cobb wrote: > I'm finding this discussion a bit ironic; in my environment, we're strongly > considering pulling all of the naming out of gmond & gmetad, and only doing > the hostname lookups in the PHP front-end. That way there's no need to deal > with DNS or host naming issues in most of the cluster(s) we monitor at all. > I suppose there's some risk in situations where the same virtual IP is bound > on many machines, but mcast_if should take care of that. My thought is that > the fewer underlying services a monitoring system needs to work, the more > likely it is to work. > This sounds like an interesting idea. It would be very easy to set a configuration flag for gmond to just turn off all DNS look ups. The lookups could then happen in either gmetad or the front end. Brad -- Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM) software. With Adobe AIR, Ajax developers can use existing skills and code to build responsive, highly engaging applications that combine the power of local resources and data with the reach of the web. Download the Adobe AIR SDK and Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com ___ Ganglia-developers mailing list Ganglia-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ganglia-developers
Re: [Ganglia-developers] Thoughts on host spoofing
On Fri, Feb 6, 2009 at 2:52 PM, Rick Cobb wrote: > My thought > is that the fewer underlying services a monitoring system needs to work, the > more likely it is to work. Absolutely, but dns itself is actually a good example of how introducing a dependency was necessary to make "a service" usable. The problem here is that if you don't have context most information are meaningless or possibly misleading and an ip imho doesn't qualify as context. When you do the lookup from the frontend the ip might have moved and this is actually not so far off depending on your infrastructure and the timeline you retain data for. Obviously if you maintain these associations elsewhere you're good, but otherwise being able to store "webXX" is pretty useful (and the reason I want more control over it). -- "Behind every great man there's a great backpack" - B. -- Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM) software. With Adobe AIR, Ajax developers can use existing skills and code to build responsive, highly engaging applications that combine the power of local resources and data with the reach of the web. Download the Adobe AIR SDK and Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com ___ Ganglia-developers mailing list Ganglia-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ganglia-developers
Re: [Ganglia-developers] Thoughts on host spoofing
I'm finding this discussion a bit ironic; in my environment, we're strongly considering pulling all of the naming out of gmond & gmetad, and only doing the hostname lookups in the PHP front-end. That way there's no need to deal with DNS or host naming issues in most of the cluster(s) we monitor at all. I suppose there's some risk in situations where the same virtual IP is bound on many machines, but mcast_if should take care of that. My thought is that the fewer underlying services a monitoring system needs to work, the more likely it is to work. -- ReC On 2/5/09 10:36 PM, "Spike Spiegel" wrote: Hi, thanks for the clarification, On Thu, Feb 5, 2009 at 11:44 PM, Brad Nicholes wrote: > Anything else the spoofing module needs to do beyond this > it completely up to the module developer. Any or all of what you > described below should just be module implementation details. Ok, so given that's the way forward as far as coding something goes, how does upstream folks feel about a patch to all the C modules to use spoofing based on a config parameter? Because that's what I need in order to solve my PTR problems and I wouldn't want to have to redo all of them in python, but on the other side if a patch wouldn't be accepted I might consider it. On a side note, has anybody done an estimation of the performance hit between a python and C module? In practice I'm thinking of a new global parameter in gmond.conf called "use_local_hostname = yes/no" which would then trigger a call to gethostname() etc... and then add the SPOOF extra data. You could also allow arbitrary strings but urm, might end up being too confusing and I'm not sure I see the use of it. -- "Behind every great man there's a great backpack" - B. -- Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM) software. With Adobe AIR, Ajax developers can use existing skills and code to build responsive, highly engaging applications that combine the power of local resources and data with the reach of the web. Download the Adobe AIR SDK and Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com ___ Ganglia-developers mailing list Ganglia-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ganglia-developers -- Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM) software. With Adobe AIR, Ajax developers can use existing skills and code to build responsive, highly engaging applications that combine the power of local resources and data with the reach of the web. Download the Adobe AIR SDK and Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com___ Ganglia-developers mailing list Ganglia-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ganglia-developers
Re: [Ganglia-developers] Thoughts on host spoofing
Hi, thanks for the clarification, On Thu, Feb 5, 2009 at 11:44 PM, Brad Nicholes wrote: > Anything else the spoofing module needs to do beyond this > it completely up to the module developer. Any or all of what you > described below should just be module implementation details. Ok, so given that's the way forward as far as coding something goes, how does upstream folks feel about a patch to all the C modules to use spoofing based on a config parameter? Because that's what I need in order to solve my PTR problems and I wouldn't want to have to redo all of them in python, but on the other side if a patch wouldn't be accepted I might consider it. On a side note, has anybody done an estimation of the performance hit between a python and C module? In practice I'm thinking of a new global parameter in gmond.conf called "use_local_hostname = yes/no" which would then trigger a call to gethostname() etc... and then add the SPOOF extra data. You could also allow arbitrary strings but urm, might end up being too confusing and I'm not sure I see the use of it. -- "Behind every great man there's a great backpack" - B. -- Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM) software. With Adobe AIR, Ajax developers can use existing skills and code to build responsive, highly engaging applications that combine the power of local resources and data with the reach of the web. Download the Adobe AIR SDK and Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com ___ Ganglia-developers mailing list Ganglia-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ganglia-developers
Re: [Ganglia-developers] Thoughts on host spoofing
A couple of clarifications.
1). Spoofing is achieved by creating a spoofing module and having that module
discover the hosts that should be spoofed, in any way the module wants. The
discovery could be done by querying the network for a specific type of device
or appliance or by simply reading a .conf file that contains information about
a spoofed host similar to what you suggested below. Once the spoofing module
knows who it is spoofing for, it creates metric definitions which associate the
spoofed metric with the spoofed host. An example of how this is done as a
python module is in the spfexample.py module that is included in the python
modules source code. Basically the only requirement is that a metric
definition be returned to gmond that includes all of the basic metric
information along with the special tags SPOOF_HOST and SPOOF_NAME. Anything
else the spoofing module needs to do beyond this, it completely up to the
module developer. Any or all of what you described below should just be module
implementation details.
2). In reality there is only one module interface that gmond understands and
that is the C interface. The python module interface is nothing more than
implementing a C module (ie. mod_python.c) that is capable of acting as a proxy
between the C interface and the python interface. The bottom line is that
gmond can be expanded to understand any language interface by simply
implementing a C module that does the translation between the C interface and
the language interface. In fact if the community believes that the
current python module interface could be much more efficient or easier to use
if it did , is simply a matter of implementing an alternative to the current
mod_python.c that does and loading the alternative module as well. The
whole idea is that the C module interface was introduced as a way to extend
gmond. What that extension is, is completely up to the imaginations of the
Ganglia community. And since the C module interface is really the only module
interface that gmond knows about, anything that can be done with the python
interface has to be done through the C interface meaning that the C interface
has all of the same functionality and much more.
Brad
>>> On 2/4/2009 at 9:11 PM, in message
, Spike Spiegel
wrote:
> Hi,
>
> while looking at taking advantage of host spoofing a few things came
> up that I'd like to discuss. Assuming that host spoofing can be used
> for:
>
> a) overriding host names because using PTRs can be a PITA depending on
> the infrastructure (for example if you have tun/ethX prefixes)
> b) streamlining appliances into ganglia
>
> I see a problem of how to manage this "spoofed hosts collection" and
> would love to see some kind of standard emerging.
> /etc/ganglia/conf.d/spoofing.cfg could be added containing definitions
> like:
>
> spoofed_host {
>hostname = spf1.example.org
>ip = 10.0.0.0
>metrics = disk_spoof, cpu_spoof
> }
>
> At this point metrics should read that file and figure out if they
> should be doing any spoofing and if so for which hosts. Not sure about
> C, but with the current python setup each module should include some
> kind of lib to do that lookup, or maybe the approach should be changed
> entirely.
>
> One problem I see is with a) is treating every host as a spoofed host,
> which might end up being confusing. Furthermore it's arguable that the
> concept of spoofing isn't itself misleading, take this example:
> - an host named myhost with a public and private interface
> - the public one resolves to task.domain.tld while the internal to
> int.task.domain.tld
> - monitoring traffic is kept on the internal network
> - as a result data is recorded and shows up as int.host.domain.tld
>
> What I'm arguing here is that "int." could be considered spoofed since
> the one the user is going to be thinking of is "task" and not int.task
> or even that both are spoofed since the real host name is myhost. You
> could blame it on poor naming and DNS practices, but I believe there
> are legit examples where simply using the PTR to save data doesn't cut
> it or whose result can be confusing. Imho much better would be to
> allow the user to specify an arbitrary name, just use what hostname
> unix command returns, and/or fallback on PTR.
>
> So I guess what I'm asking here is: should this be accomplished with
> host spoofing, maybe allowing a hostname = something in gmond.conf and
> hiding it from the user or do people feel that PTR is The Way and if
> you want otherwise you deal with it yourself using spoofing.cfg or
> something like that?
>
> On a related note, initially I believed the spoofing functionality to
> be tied to the python modules, but then I noticed this in the STATUS
> file:
>
> * Allow both a C and python module to create a metric that will spoof a
> specific host. This provides the same spoofing functionality as gmetric
> but through a metric module. It
[Ganglia-developers] Thoughts on host spoofing
Hi,
while looking at taking advantage of host spoofing a few things came
up that I'd like to discuss. Assuming that host spoofing can be used
for:
a) overriding host names because using PTRs can be a PITA depending on
the infrastructure (for example if you have tun/ethX prefixes)
b) streamlining appliances into ganglia
I see a problem of how to manage this "spoofed hosts collection" and
would love to see some kind of standard emerging.
/etc/ganglia/conf.d/spoofing.cfg could be added containing definitions
like:
spoofed_host {
hostname = spf1.example.org
ip = 10.0.0.0
metrics = disk_spoof, cpu_spoof
}
At this point metrics should read that file and figure out if they
should be doing any spoofing and if so for which hosts. Not sure about
C, but with the current python setup each module should include some
kind of lib to do that lookup, or maybe the approach should be changed
entirely.
One problem I see is with a) is treating every host as a spoofed host,
which might end up being confusing. Furthermore it's arguable that the
concept of spoofing isn't itself misleading, take this example:
- an host named myhost with a public and private interface
- the public one resolves to task.domain.tld while the internal to
int.task.domain.tld
- monitoring traffic is kept on the internal network
- as a result data is recorded and shows up as int.host.domain.tld
What I'm arguing here is that "int." could be considered spoofed since
the one the user is going to be thinking of is "task" and not int.task
or even that both are spoofed since the real host name is myhost. You
could blame it on poor naming and DNS practices, but I believe there
are legit examples where simply using the PTR to save data doesn't cut
it or whose result can be confusing. Imho much better would be to
allow the user to specify an arbitrary name, just use what hostname
unix command returns, and/or fallback on PTR.
So I guess what I'm asking here is: should this be accomplished with
host spoofing, maybe allowing a hostname = something in gmond.conf and
hiding it from the user or do people feel that PTR is The Way and if
you want otherwise you deal with it yourself using spoofing.cfg or
something like that?
On a related note, initially I believed the spoofing functionality to
be tied to the python modules, but then I noticed this in the STATUS
file:
* Allow both a C and python module to create a metric that will spoof a
specific host. This provides the same spoofing functionality as gmetric
but through a metric module. It is done by adding SPOOF_HOST and
SPOOF_NAME as extra metadata to the metric description
Based on that it should be possible to allow spoofing from the
standard C modules distributed with ganglia, correct? How would that
be done? I've looked at some of the existing metrics and noticed calls
to MMETRIC_ADD_METADATA, would that be it?
thanks
--
"Behind every great man there's a great backpack" - B.
--
Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM)
software. With Adobe AIR, Ajax developers can use existing skills and code to
build responsive, highly engaging applications that combine the power of local
resources and data with the reach of the web. Download the Adobe AIR SDK and
Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com
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