perfsonar development work

[Danijel Matek <>]

Giovanni Cesaroni wrote:
> Hi,
> in the case of GARR,
> we have one loopback IP address per router (it is not necessarily so for 
> others).
> We use the DNS name in the "nmwgt:hostName" of the RRDMA XML
> and the loopback IP in the configuration of the SSH/telnet.

Yes, I'm aware of this. But if I can query DNS for the IP address of the 
hostName in RRD MA it really doesn't mater.

If we make a rule that if loopback host name is available then write 
host name first and if it's not write an IP address and apply that rule 
to every service that deals with loopback info then there will be no 
mismatch.

This rule will save as only one DNS query, so the question is does it 
worth the overhead of writing and forcing the rule?.


> We could also change the the loopback with the DNS in the SSH/telnet 
> configuration.
>
> So everything mentioned in this mail thread is possible, but the problem 
> is that, even if the SSH/telnet service has much improved, is not in our 
> opinion so mature to interact with the production routers.
>
> Cheers,
> Giovanni
>
> Danijel Matek wrote:
> > Nicolas Simar wrote:
> > > Hi Danijel,
> > >
> > > this is much better :-)
> > >
> > > 1) Reading you, do I understand that the RRD MA already provides the 
> > > "nmwgt:hostName" when you request the data about the utilisation?
> >
> > Yes it does as you can see from the part of MA configuration 
> > specification document I've sent you.
> >
> > I've seen querying the different MAes that everybody filled the 
> > "hostName" in their configuration files. Try clicking on "show on map" 
> > link or on router icon in VisualPerfSONAR after you started the survey 
> > and you'll see the host name info.
> >
> > As I sad before the problem is that the hostname field in 
> > configuration specification is optional when it suould be mandatory. 
> > To make it mandatory there is a need for slight modification in NMWG 
> > schema so that when you try to validate the configuration file it 
> > informs you that you have to fill the hostname filed. We also need to 
> > extend the description of the field so that IP address can be entered 
> > also if the host name of the loopback isn't available. This is all 
> > explained in this demo specification.
> >
> >
> > > 2) Forgive my ignorance, but what is "URL property in the SSH/Telent 
> > > MP"? Does it has the same value as "nmwgt:hostName"?
> >
> > The URL property is in fact the loopback address of the device(router).
> > There is a great possibility that they'll match. The only case when 
> > they will not match is if in MA configuration hostname property is the 
> > name of the host loopback and URL property IP address of the loopback. 
> > But this can be easily solved querying the DNS. So this is no problem 
> > at all.
> >
> > > 3) If I read you properly, there are no modification required on the 
> > > web-service code. We only need (i) some information ("nmwgt:hostName" 
> > > and URL property from the Telnet/SSH MP to be configured with the 
> > > same entries by the web-services deployers and (ii) all those 
> > > services registering to the same LS. Have I understood you properly?
> > > If this is the case, I am terribly thrilled by what you said!
> >
> > You are absolutely write. But before we start the dance of joy it is 
> > better to ask the service developers for confirmation.
> >
> > > 4) To test the feature, you would need one network having fulfilled 3
> >
> > Yes. If Stijn has deploy RRD MA where he's collecting data from the 
> > router he has in his SSH/Telnet MP we can do this NOW.
> >
> >
> >
> > IMPORTANT: By applying these simple rules:
> >     1. hostname to be mandatory instead of optional in RRD MA
> >     2. in hostname field you should be able to enter IP address also 
> > (this is just a change in description)
> >     3. change this in all services dealing with loopback info.
> > --------------------------------------------------------------------------- 
> >
> > This will greatly improve correlation abilities between different 
> > services for no cost at all.
> >
> >
> >
> >
> >
> > > Thanks a lot.
> > >
> > > Cheers,
> > > Nicolas
> > >
> > >
> > >
> > > Danijel Matek wrote:
> > > [snip]
> > > > Hi,
> > > >
> > > > Ok, here it goes....
> > > >
> > > >
> > > > Running Show Commands On Routers Along The Traceroute Path
> > > > ==========================================================
> > > >
> > > > We want to initiate a set of requests based on traceroute output to 
> > > > get the link utilization, interface drops and interface errors for 
> > > > all the hops along the traceroute path. Further more we want to be 
> > > > able to identify the routers hosting the interfaces so that we can 
> > > > run some show commands through the SSH/Telenet MP on the identified 
> > > > routers.
> > > >
> > > >
> > > > So, how do we do this???
> > > > ------------------------
> > > >
> > > > We want to map "nmwgt:hostName" from the RRD MA with the URL 
> > > > property in the SSH/Telent MP.
> > > >
> > > > Let's take a look at RRD MA service configuration specification.
> > > > This is the part of the "Metadata_Configuration_specification.doc" 
> > > > for the RRD MA:
> > > >
> > > > "Element-Name: nmwgt:hostName
> > > > Mandatory: NO
> > > > Description: Network element (router, switch) hostname. Should be a 
> > > > loopback interface host name."
> > > >
> > > > This shows that we already have a means to get the router loopback 
> > > > hostname.
> > > >
> > > > Problem 1: nmwgt:hostName is not Mandatory
> > > > Suggestion: make it mandatory
> > > >
> > > > Problem 2: some routers don't have loopback interface host name, but 
> > > > only IP address of the lo interface
> > > > Suggestion: the description should say: "Network element (router, 
> > > > switch) hostname or IP. Should be a loopback interface host name or 
> > > > IP.".
> > > >
> > > >
> > > > At this point we can assume that when we get the info form the RRD 
> > > > MA about the traceroute output given interface we'll get the 
> > > > hostname of the router. (You can actually see this in 
> > > > VisualPerfSonar when you click on a router icon in a google map or 
> > > > "show on map" link)
> > > >
> > > > In order for this demo to work we need to be sure that the 
> > > > "nmwgt:hostName" is exactly the same as the URL property in the 
> > > > SSH/Telent MP.
> > > >
> > > > This is the part of the "Service.Properties Configuration Files For 
> > > > SSH/Telnet 1.0.doc":
> > > > "URL property
> > > > Name: service.r.mp.<device>.url
> > > > <device> is the symbolic name specified in the device property.
> > > > Mandatory: Mandatory
> > > > Description: Represents the IP or Hostname of the device to be 
> > > > contacted"
> > > >
> > > >
> > > > Suggestion( IMPORTANT !!! ): We have to make a rule that if there is 
> > > > a hostname we'll use hostname in nmwgt:hostName and in URL property 
> > > > and if we only have an IP address of a loopback interface will use 
> > > > the IP address. This rule should be extended to all services that 
> > > > has loopback hostname or IP address mentioned in its configuration. 
> > > > Why??? If we do this well be able to correlate more services 
> > > > together in a very clear, intuitive and simple way. By adding this 
> > > > simple rule we will automatically extend perfsonar functionality.
> > > >
> > > > Note: This should not be for demo and testing purposes only!!!
> > > >
> > > >
> > > > Client action:
> > > > --------------
> > > >
> > > > 1. Client will take the addresses from the traceroute output and try 
> > > > to contact the lookup service to ask for the RRD MA services that 
> > > > holds the information about the addresses involved.
> > > >
> > > > 2. Connect to the given MA service get the bandwidth utilization 
> > > > data, interface errors, interface drops and get the nmwgt:hostName.
> > > >
> > > > 3. Ask LS about SSH/Telnet MP for a given nmwgt:hostName.(See note)
> > > >
> > > > 4. Query the SSH/Telenet MP and run some show commands
> > > >
> > > > 5. Show the data in client
> > > >
> > > > Note: RRD MA is registering it's configuration to the LS and there 
> > > > for the hostname element name. And even if it's not registering the 
> > > > hostname, when the client is getting the info about the given 
> > > > interface it gets the hostname. Based on the wiki SSH/Telnet MP is 
> > > > still not registering to the LS so we can't ask LS for the location 
> > > > of SSH/Telnet MP. For this case we can use some service discovery 
> > > > methods we were using before the LS was created.
> > > >
> > > >
> > > > Assumption: If Stajn has deployed SSH/Telnet MP with a router that 
> > > > has its interfaces configured in Stajns RRD MA there is a great 
> > > > possibility that we'll be able to run this demo right now.
> > > >
> > > >
> > > > P.S.
> > > > Please send me a note if you need me to elaborate something in more 
> > > > detail or if something is not clear. And If you like this you can 
> > > > buy me a beer on the next meeting. :-)
> > > >
> > > >
> > > > Danijel