perfSONAR User Q&A and Other Discussion

[Andrew Lake <>]

Hi Weiping,

The first should work and is what you want. Which gLS did you send the 
request to? I sent the exact request to 
"http://ps4.es.net:9990/perfSONAR_PS/services/gLS"; and it worked.

Andy



On May 3, 2010, at 12:41 PM, Weiping Mandrawa wrote:

> Hi Andy,
> 
> I did try as you suggested
> 
> 
> my $xquery = "declare namespace 
> nmwg=\"http://ggf.org/ns/nmwg/base/2.0/\";\n";;
> $xquery .= 
> "/nmwg:store[\@type=\"LSStore\"]/nmwg:data/nmwg:metadata/summary:parameters/nmwg:parameter[\@name=\"keyword\"]";
> 
> my $gLSResult = $glsClient->queryRequestLS(
>        {   
>            query => $xquery, 
>            format => 1 #want response to be formated as XML
>        }
>    );
> 
> and it return nothing.
> 
> I tried to modify a code a little bit
> my $xquery = "declare namespace 
> nmwg=\"http://ggf.org/ns/nmwg/base/2.0/\";\n";;
> $xquery .= "for \$metadata in 
> /nmwg:store[\@type=\"LSStore\"]/nmwg:metadata\n";
> $xquery .= "    let \$metadata_id := 
> \$metadata/\@id
>   \n";
> $xquery .= "    let \$data := 
> /nmwg:store[\@type=\"LSStore\"]/nmwg:data/nmwg:metadata/summary:parameters/nmwg:parameter[\@name=\"keyword\"]\n";
> $xquery .= "    return 
> \$metadata/perfsonar:subject/psservice:service/psservice:accessPoint";
> 
> 
> # Send query to the global lookup service
> my $gLSResult = $glsClient->queryRequestLS(
>        {   
>            query => $xquery, 
>            format => 1 #want response to be formated as XML
>        }
>    );
> 
> and it returns something like this
> 
> GLS Response = <psservice:datum 
> xmlns:psservice="http://ggf.org/ns/nmwg/tools/org/perfsonar/service/1.0/";><psservice:accessPoint
>  
> xmlns:psservice="http://ggf.org/ns/nmwg/tools/org/perfsonar/service/1.0/";>http://129.82.183.103:8095/perfSONAR_PS/services/hLS</psservice:accessPoint><psservice:accessPoint
>  
> xmlns:psservice="http://ggf.org/ns/nmwg/tools/org/perfsonar/service/1.0/";>http://18.12.1.172:8095/perfSONAR_PS/services/hLS</psservice:accessPoint><psservice:accessPoint
>  
> xmlns:psservice="http://ggf.org/ns/nmwg/tools/org/perfsonar/service/1.0/";>http://ps-bw.es.net:8095/perfSONAR_PS/services/hLS</psservice:accessPoint>
> 
> 
> and based on result, I can't find any keyword related that have something 
> like project:ESnet
> 
> 
> Thank you
> 
> 
>>>> Andrew Lake 
>>>> <>
>>>>  4/30/2010 3:34 PM >>>
> Hi Weiping,
> 
> Send an XQuery like the following to one of the global Lookup Services 
> (gLS):
> 
> my $xquery = "declare namespace 
> nmwg=\"http://ggf.org/ns/nmwg/base/2.0/\";\n";;
> $xquery .= 
> "/nmwg:store[\@type=\"LSStore\"]/nmwg:data/nmwg:metadata/summary:parameters/nmwg:parameter[\@name=\"keyword\"]";
> 
> The "value" attribute in the returned elements will contain the keywords. 
> You'll have to sort out the unique ones. A list of global lookup services 
> where you can send the above query are listed here: 
> http://www.perfsonar.net/gls.root.hints. You only need to send the request 
> to one since they should all be synced. A few on the list occasionally have 
> problems so you may just want to stick to the es.net and internet2.edu 
> services. 
> 
> Also the checks are case sensitive. This is a feature of xquery. There are 
> some ways to make XQuery do a case insensitive search but none of them are 
> that straight-forward.
> 
> Let me know if you need any clarification on the info above.
> 
> Thanks!
> Andy
> 
> On Apr 30, 2010, at 2:01 PM, Weiping Mandrawa wrote:
> 
>> Andy,
>> 
>> Thank you for clarification and quick response.
>> 
>> I tested the code and it is working well.
>> 
>> 
>> I have another question, 
>> 
>> let say I want to filter my lookup search based on Project name (e.g 
>> ESnet) and 
>> in the example code (ls-ex3-bwctl.pl)
>> 
>> \$keyword=\"project:ESnet\" . Is this case sensitive ? 
>> and how do I get list of keyword "project"
>> e.g LBNL, Internet2 etc to be used with lookup service
>> 
>> 
>> Thank you
>> 
>> Kind Regards
>> 
>> Weiping
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>>>>> Andrew Lake 
>>>>> <>
>>>>>  04/30/10 1:28 PM >>>
>> Hi Weiping,
>> 
>> The html on the page was causing those lines to be displayed incorrectly. 
>> The </ in the regular expression was the source of the problem. I have now 
>> corrected the page. The correct code block looks like the following:
>> 
>> if( $hLSResult->{response} && $hLSResult->{response} =~ /^<./ ){
>>           # Print list of matching bwctl server addresses
>>           my $resParser = XML::LibXML->new();
>>           my $hLSDoc = $resParser->parse_string($hLSResult->{response});
>> 
>> Also, if it helps you may download the code examples on this page here: 
>> http://psps.perfsonar.net/ps-client-examples-v1.1.tar.gz. There is also a 
>> link to this file on the bottom of the page.
>> 
>> Thanks!
>> Andy
>> 
>> 
>> On Apr 30, 2010, at 1:09 PM, Jason Zurawski wrote:
>> 
>>> Hello,  I am trying to understand lookup service based on the address
>>> 
>>> http://psps.perfsonar.net/client-doc.html 
>>> 
>>> In the paragraph
>>> 
>>> The instance in the above example is the URL of an LS service to contact. 
>>> Examples
>>> 1. Find all SNMP Measurement Archives
>>> 
>>> 
>>> There are examples how to crate XQuery to be sent to home lookup services
>>> 
>>> In the example code (XQuery to be sent up to home lookup based on Find 
>>> all SNMP Measurement Archieves)
>>> 
>>> 
>>> (Line1) if($hLSResult->{response} && $hLSResult->{response} =~ /^new();
>>> (Line2)            my $hLSDoc = 
>>> $resParser->parse_string($hLSResult->{response});
>>> 
>>> 
>>> 
>>> For some reason, perl can't understand (Line1) to (Line2)
>>> 
>>> for example
>>> 
>>> in Line2 , it is using $resParser but $resParser is not declared anywhere 
>>> in the code
>>> and when I run the code, it complains about it
>>> 
>>> 
>>> 
>>> if I change $resParser to $parser, it complains that
>>> 
>>> Thread 65 terminated abnormally: Can't call method "parse_string" on 
>>> unblessed reference
>>> 
>>> 
>>> Thank you
>>> 
>> 
>> 
>