perfSONAR_PS::Client::LS::Remote - A module that provides a client API for an LS

perfSONAR_PS-Client-LS-Remote documentation  | view source Contained in the perfSONAR_PS-Client-LS-Remote distribution.

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NAME

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perfSONAR_PS::Client::LS::Remote - A module that provides a client API for an LS

DESCRIPTION

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This module aims to offer simple methods for dealing with requests for information, and the related tasks of interacting with backend storage.

SYNOPSIS

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    use perfSONAR_PS::Client::LS::Remote;

    my %conf = ();
    $conf{"SERVICE_ACCESSPOINT"} = "http://someorganization.org:8080/perfSONAR_PS/services/service";
    $conf{"SERVICE_NAME"} = "Some Organization's Service MA"
    $conf{"SERVICE_TYPE"} = "MA"
    $conf{"SERVICE_DESCRIPTION"} = "Service MA"

    my $ls = "http://someorganization.org:8080/perfSONAR_PS/services/LS";

    my $ls_client = perfSONAR_PS::Client::LS::Remote->new($ls, \%conf, \%ns);

    # or
    # $ls_client = perfSONAR_PS::Client::LS::Remote->new;
    # $ls_client->setURI($ls);
    # $ls_client->setConf(\%conf);
    # $ls_client->setNamespaces(\%ns);

    $ls_client->registerStatic(\@data);

    $ls_client->sendKeepalive($conf{"SERVICE_ACCESSPOINT"});

    $ls_client->sendDeregister($conf{"SERVICE_ACCESSPOINT"});

    my $ls2 = "http://otherorganization.org:8080/perfSONAR_PS/services/LS";

    my $ls_client2 = perfSONAR_PS::Client::LS::Remote->new($ls2);

    my %queries = ();

    $queries{"req1"} = "";
    $queries{"req1"} .= "declare namespace nmwg=\"http://ggf.org/ns/nmwg/base/2.0/\";\n";
    $queries{"req1"} .= "for \$data in /nmwg:store/nmwg:data\n";
    $queries{"req1"} .= "  let \$metadata_id := \$data/\@metadataIdRef\n";
    $queries{"req1"} .= "  where \$data//*:link[\@id=\"link1\"] and \$data//nmwg:eventType[text()=\"http://ggf.org/ns/nmwg/characteristic/link/status/20070809\"]\n";
    $queries{"req1"} .= " return /nmwg:store/nmwg:metadata[\@id=\$metadata_id]\n";

    $queries{"req2"} = "";
    $queries{"req2"} .= "declare namespace nmwg=\"http://ggf.org/ns/nmwg/base/2.0/\";\n";
    $queries{"req2"} .= "for \$data in /nmwg:store/nmwg:data\n";
    $queries{"req2"} .= "  let \$metadata_id := \$data/\@metadataIdRef\n";
    $queries{"req2"} .= "  where \$data//*:link[\@id=\"link2\"] and \$data//nmwg:eventType[text()=\"http://ggf.org/ns/nmwg/characteristic/link/status/20070809\"]\n";
    $queries{"req2"} .= " return /nmwg:store/nmwg:metadata[\@id=\$metadata_id]\n";

    my ($status, $res) = $ls_client2->query(\%queries);
    if ($status != 0 or not defined $res{"req1"} or not defined $res{"req2"}) {
      print "Error: querying $ls2 failed\n";
      exit(-1);
    }

    my ($query_status, $query_res);

    ($query_status, $query_res) = $res{"req1"};

    if ($query_status != 0) {
      print "Couldn't get information on query req1: ".$query_res."\n";
      exit(-1);
    } else {
      print "Results for res1: ".$query_res->toString()."\n";
    }

    ($query_status, $query_res) = $res{"req2"};

    if ($query_status != 0) {
      print "Couldn't get information on query req2: ".$query_res."\n";
      exit(-1);
    } else {
      print "Results for res1: ".$query_res->toString()."\n";
    }

API

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The offered API is simple, but offers the key functions we need in a measurement archive.

new ($package, $uri, \%conf)

The parameters are the URI of the Lookup Service, a %conf describing the service for registration purposes.

The %conf can have 4 keys in it:

SERVICE_NAME - The name of the service registering data SERVICE_ACCESSPOINT - The URL for the service registering data SERVICE_TYPE - The type (MA, LS, etc) of the service registering data SERVICE_DESCRIPTION - A description of the service registering data

setURI ($self, $uri) (Re-)Sets the value for the LS URI. =cut

sub setURI { my ($self, $uri) = @_; my $logger = get_logger("perfSONAR_PS::Client::LS::Remote");

    if(defined $uri and $uri ne "") {
        $self->{URI} = $uri;
    }
    else {
        $logger->error("Missing argument.");
    }
    return;

}

setConf ($self, \%conf) (Re-)Sets the value for the 'conf' hash. =cut sub setConf { my ($self, $conf) = @_; my $logger = get_logger("perfSONAR_PS::Client::LS::Remote");

    if(defined $conf and $conf ne "") {
        $self->{CONF} = \%{$conf};
    }
    else {
        $logger->error("Missing argument.");
    }
    return;
}

createKey ($self, $key) Creates a 'key' value that is used to access the LS. =cut sub createKey { my($self, $lsKey) = @_; my $key = " <nmwg:key id=\"key.".genuid()."\">\n"; $key = $key . " <nmwg:parameters id=\"parameters.".genuid()."\">\n"; if (defined $lsKey and $lsKey ne "") { $key = $key . " <nmwg:parameter name=\"lsKey\">".$lsKey."</nmwg:parameter>\n"; } else { $key = $key . " <nmwg:parameter name=\"lsKey\">".$self->{CONF}->{"SERVICE_ACCESSPOINT"}."</nmwg:parameter>\n"; } $key = $key . " </nmwg:parameters>\n"; $key = $key . " </nmwg:key>\n"; return $key; }

createService ($self) Creates the 'service' subject (description of the service) for LS registration. =cut sub createService { my($self) = @_; my $logger = get_logger("perfSONAR_PS::Client::LS::Remote"); my $service = " <perfsonar:subject xmlns:perfsonar=\"http://ggf.org/ns/nmwg/tools/org/perfsonar/1.0/\">\n"; $service = $service . " <psservice:service xmlns:psservice=\"http://ggf.org/ns/nmwg/tools/org/perfsonar/service/1.0/\">\n"; $service = $service . " <psservice:serviceName>".$self->{CONF}->{"SERVICE_NAME"}."</psservice:serviceName>\n" if (defined $self->{CONF}->{"SERVICE_NAME"}); $service = $service . " <psservice:accessPoint>".$self->{CONF}->{"SERVICE_ACCESSPOINT"}."</psservice:accessPoint>\n" if (defined $self->{CONF}->{"SERVICE_ACCESSPOINT"}); $service = $service . " <psservice:serviceType>".$self->{CONF}->{"SERVICE_TYPE"}."</psservice:serviceType>\n" if (defined $self->{CONF}->{"SERVICE_TYPE"}); $service = $service . " <psservice:serviceDescription>".$self->{CONF}->{"SERVICE_DESCRIPTION"}."</psservice:serviceDescription>\n" if (defined $self->{CONF}->{"SERVICE_DESCRIPTION"}); $service = $service . " </psservice:service>\n"; $service = $service . " </perfsonar:subject>\n"; return $service; }

callLS ($self, $sender, $message) Given a message and a sender, contact an LS and parse the results. =cut sub callLS { my($self, $sender, $message) = @_; my $logger = get_logger("perfSONAR_PS::Client::LS::Remote"); my $error; my $responseContent = $sender->sendReceive(makeEnvelope($message), "", \$error); if($error ne "") { $logger->error("sendReceive failed: $error"); return -1; } my $parser = XML::LibXML->new(); if(defined $responseContent and $responseContent ne "" and not ($responseContent =~ m/^\d+/x)) { my $doc = ""; eval { $doc = $parser->parse_string($responseContent); }; if($@) { $logger->error("Parser failed: ".$@); return -1; } else { my $msg = $doc->getDocumentElement->getElementsByTagNameNS("http://ggf.org/ns/nmwg/base/2.0/", "message")->get_node(1); if($msg) { my $eventType = findvalue($msg, "./nmwg:metadata/nmwg:eventType"); if(defined $eventType and $eventType =~ m/success/x) { return 0; } } } } return -1; }

sendDeregister ($self, $key) Deregisters the data with the specified key =cut sub sendDeregister { my ($self, $key) = @_;

    if (not defined $self->{URI}) {
        return -1;
    }

    my ($host, $port, $endpoint) = &perfSONAR_PS::Transport::splitURI($self->{URI});
    if (not defined $host and not defined $port and not defined $endpoint) {
        return -1;
    }

    my $sender = new perfSONAR_PS::Transport($host, $port, $endpoint);




    my $doc = perfSONAR_PS::XML::Document_string->new();
    startMessage($doc, "message.".genuid(), "", "LSDeregisterRequest", "", {perfsonar=>"http://ggf.org/ns/nmwg/tools/org/perfsonar/1.0/", psservice=>"http://ggf.org/ns/nmwg/tools/org/perfsonar/service/1.0/"});

    my $mdID = "metadata.".genuid();
    createMetadata($doc, $mdID, "", createKey($self, $key), undef);
    createData($doc, "data.".genuid(), $mdID, "", undef);
    endMessage($doc);

    return callLS($self, $sender, $doc->getValue());
}

sendKeepalive ($self, $key) Sends a keepalive message for the data with the specified key =cut sub sendKeepalive { my ($self, $key) = @_;

    if (not defined $self->{URI}) {
        return -1;
    }

    my ($host, $port, $endpoint) = &perfSONAR_PS::Transport::splitURI($self->{URI});
    if (not defined $host and not defined $port and not defined $endpoint) {
        return -1;
    }

    my $sender = new perfSONAR_PS::Transport($host, $port, $endpoint);




    my $doc = perfSONAR_PS::XML::Document_string->new();
    startMessage($doc, "message.".genuid(), "", "LSKeepaliveRequest", "", {perfsonar=>"http://ggf.org/ns/nmwg/tools/org/perfsonar/1.0/", psservice=>"http://ggf.org/ns/nmwg/tools/org/perfsonar/service/1.0/"});

    my $mdID = "metadata.".genuid();
    createMetadata($doc, $mdID, "", createKey($self, $key), undef);
    createData($doc, "data.".genuid(), $mdID, "", undef);
    endMessage($doc);

    return callLS($self, $sender, $doc->getValue());
}

registerStatic ($self, \@data_ref) Performs registration of 'static' data with an LS. Static in this sense indicates that the data in the underlying storage DOES NOT change. This function uses special messages that intend to simply keep the data alive, not worrying at all if something comes in that is new or goes away that is old. =cut sub registerStatic { my($self, $data_ref) = @_; my $logger = get_logger("perfSONAR_PS::Client::LS::Remote");

    if (not defined $self->{URI}) {
        return -1;
    }

    if(!$self->{ALIVE}) {
        my $echo_service = perfSONAR_PS::Client::Echo->new($self->{URI});
        my ($status, $res) = $echo_service->ping();
        if ($status == -1) {
            $logger->error("Ping to ".$self->{URI}." failed: $res");
            return -1;
        }
        $self->{ALIVE} = 1;
    }

    if($self->{FIRST}) {
        if ($self->sendDeregister($self->{CONF}->{"SERVICE_ACCESSPOINT"}) == 0) {
            $logger->debug("Nothing registered.");
        }
        else {
            $logger->debug("Removed old registration.");
        }

        my @resultsString = ();

        @resultsString = @{$data_ref};

        if($#resultsString != -1) {
            my ($status, $res) = $self->__register(createService($self), $data_ref);
            if ($status == -1) {
                $logger->error("Unable to register data with LS.");
                $self->{ALIVE} = 0;
            }
        }
    }
    else {
        if ($self->sendKeepalive() == -1) {
            my @resultsString = ();

            @resultsString = @{$data_ref};

            if($#resultsString != -1) {
                my ($status, $res) = $self->__register(createService($self), $data_ref);
                if ($status == -1) {
                    $logger->error("Unable to register data with LS.");
                    $self->{ALIVE} = 0;
                    return -1;
                }
            }
        }
    }

    $self->{FIRST} = 0 if $self->{FIRST};
    return 0;
}

__register ($self, $subject, $data_ref) Performs the actual data registration. Unlike the above registration functions, this function does not try to perform any of the keepalive/deregister registration tricks. It simply registers the specified data. As part of the registration, it splits the data into chunks and registers each independently. =cut sub __register { my ($self, $subject, $data_ref) = @_; my $logger = get_logger("perfSONAR_PS::Client::LS::Remote");

    if (not defined $self->{URI}) {
        return -1
    }

    my ($host, $port, $endpoint) = &perfSONAR_PS::Transport::splitURI($self->{URI});
    if (not defined $host and not defined $port and not defined $endpoint) {
        return -1
    }

    my $sender = new perfSONAR_PS::Transport($host, $port, $endpoint);

    my @data = @{ $data_ref };
    my $iterations = int((($#data+1)/$self->{CHUNK}));
    my $x = 0;

    for(my $y = 1; $y <= ($iterations+1); $y++) {
        my $doc = perfSONAR_PS::XML::Document_string->new();
        startMessage($doc, "message.".genuid(), "", "LSRegisterRequest", "", {perfsonar=>"http://ggf.org/ns/nmwg/tools/org/perfsonar/1.0/", psservice=>"http://ggf.org/ns/nmwg/tools/org/perfsonar/service/1.0/"});
        my $mdID = "metadata.".genuid();
        createMetadata($doc, $mdID, "", createService($self), undef);
        for(; $x < ($y*$self->{CHUNK}) and $x <= $#data; $x++) {
            createData($doc, "data.".genuid(), $mdID, $data[$x], undef);
        }
        endMessage($doc);
        unless(callLS($self, $sender, $doc->getValue()) == 0) {
            $logger->error("Unable to register data with LS.");
            return -1;
        }
    }

    return 0;
}

registerDynamic ($self, \@data_ref) Performs registration of 'dynamic' data with an LS. Dynamic in this sense indicates that the data in the underlying storage DOES change. This function uses special messages that will remove all old data and insert everything brand new with each registration. =cut sub registerDynamic { my($self, $data_ref) = @_; my $logger = get_logger("perfSONAR_PS::Client::LS::Remote");

    if (not defined $self->{URI}) {
        return -1;
    }

    if(!$self->{ALIVE}) {
        my $echo_service = perfSONAR_PS::Client::Echo->new($self->{URI});
        my ($status, $res) = $echo_service->ping();
        if ($status == -1) {
            $logger->error("Ping to ".$self->{URI}." failed: $res");
            return -1;
        }

        $self->{ALIVE} = 1;
    }

    if($self->{FIRST}) {
        if ($self->sendDeregister($self->{CONF}->{"SERVICE_ACCESSPOINT"}) == 0) {
            $logger->debug("Nothing registered.");
        }
        else {
            $logger->debug("Removed old registration.");
        }

        my @resultsString = @{$data_ref};

        if($#resultsString != -1) {
            if ($self->__register(createService($self), $data_ref) == -1) {
                $logger->error("Unable to register data with LS.");
                $self->{ALIVE} = 0;
            }
        }
    } else {
        my @resultsString = @{$data_ref};

        my $subject = "";
        if ($self->sendKeepalive() == -1) {
            $subject = createService($self);
        }
        else {
            $subject = createKey($self, $self->{CONF}->{SERVICE_ACCESSPOINT})."\n".createService($self);
        }

        if($#resultsString != -1) {
            if ($self->__register($subject, $data_ref) == -1) {
                $logger->error("Unable to register data with LS.");
                $self->{ALIVE} = 0;
                return -1;
            }
        }
    }

    $self->{FIRST} = 0 if ($self->{FIRST});

    return 0;
}

query ($self, \%queries) This function sends the specified queries to the LS and returns the results. The queries are given as a hash table with each key/value pair being an identifier/a query. Each query gets executed and the returned value is a hash containing the same identifiers as keys, but instead of pointing to queries, they point to an array containing a status and a result. The status is either 0 or -1. If it's 0, the result is a pointer to the data element. If it's -1, the result is the error message. =cut sub query { my ($self, $queries) = @_; my $logger = get_logger("perfSONAR_PS::Client::LS::Remote");

    if (not defined $self->{URI}) {
        return -1;
    }

    my ($host, $port, $endpoint) = &perfSONAR_PS::Transport::splitURI($self->{URI});
    if (not defined $host and not defined $port and not defined $endpoint) {
        return -1;
    }

    my $request = "";
    $request .= "<nmwg:message type=\"LSQueryRequest\" id=\"msg1\"\n";
    $request .= "     xmlns:nmwg=\"http://ggf.org/ns/nmwg/base/2.0/\"\n";
    $request .= "     xmlns:xquery=\"http://ggf.org/ns/nmwg/tools/org/perfsonar/service/lookup/xquery/1.0/\">\n";
    foreach my $query_id (keys %{ $queries }) {
        $request .= "  <nmwg:metadata id=\"perfsonar_ps.meta.$query_id\">\n";
        $request .= "    <xquery:subject id=\"sub1\">\n";
        $request .= $queries->{$query_id};
        $request .= "    </xquery:subject>\n";
        $request .= "    <nmwg:eventType>http://ggf.org/ns/nmwg/tools/org/perfsonar/service/lookup/xquery/1.0</nmwg:eventType>\n";
        $request .= "  <xquery:parameters id=\"params.1\">\n";
        $request .= "    <nmwg:parameter name=\"lsOutput\">native</nmwg:parameter>\n";
        $request .= "  </xquery:parameters>\n";
        $request .= "  </nmwg:metadata>\n";
        $request .= "  <nmwg:data metadataIdRef=\"perfsonar_ps.meta.$query_id\" id=\"data.$query_id\"/>\n";
    }
    $request .= "</nmwg:message>\n";

    my ($status, $res) = consultArchive($host, $port, $endpoint, $request);
    if ($status != 0) {
        my $msg = "Error consulting LS: $res";
        $logger->error($msg);
        return -1;
    }

    $logger->debug("Response: ".$res->toString);

    my %ret_structure = ();

    foreach my $d ($res->getChildrenByTagName("nmwg:data")) {
        foreach my $m ($res->getChildrenByTagName("nmwg:metadata")) {
            my $md_id = $m->getAttribute("id");
            my $md_idref = $m->getAttribute("metadataIdRef");
            my $d_idref = $d->getAttribute("metadataIdRef");

            if($md_id eq $d_idref) {
                my $query_id;
                my $eventType = findvalue($m, "nmwg:eventType");

                if (defined $md_idref and $md_idref =~ /perfsonar_ps\.meta\.(.*)/x) {
                    $query_id = $1;
                } elsif ($md_id =~ /perfsonar_ps\.meta\.(.*)/x) {
                    $query_id = $1;
                } else {
                    my $msg = "Received unknown response: $md_id/$md_idref";
                    $logger->error($msg);
                    next;
                }

                my @retval;
                if (defined $eventType and $eventType =~ /^error\./x) {
                    my $error_msg = findvalue($d, "./nmwgr:datum");
                    $error_msg = "Unknown error" if (not defined $error_msg or $error_msg eq "");
                    @retval = (-1, $error_msg);
                } else {
                    @retval = (0, $d);
                }

                $ret_structure{$query_id} = \@retval;
            }
        }
    }

    return (0, \%ret_structure);
}

1;

__END__

SEE ALSO

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Log::Log4perl, perfSONAR_PS::Common, perfSONAR_PS::Transport, perfSONAR_PS::Messages, perfSONAR_PS::Client::Echo

To join the 'perfSONAR-PS' mailing list, please visit:

  https://mail.internet2.edu/wws/info/i2-perfsonar

The perfSONAR-PS subversion repository is located at:

  https://svn.internet2.edu/svn/perfSONAR-PS

Questions and comments can be directed to the author, or the mailing list. Bugs, feature requests, and improvements can be directed here:

  https://bugs.internet2.edu/jira/browse/PSPS

VERSION

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$Id$

AUTHOR

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Aaron Brown, aaron@internet2.edu Jason Zurawski, zurawski@internet2.edu

LICENSE

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You should have received a copy of the Internet2 Intellectual Property Framework along with this software. If not, see <http://www.internet2.edu/membership/ip.html>

COPYRIGHT

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Copyright (c) 2004-2008, Internet2 and the University of Delaware

All rights reserved.

perfSONAR_PS-Client-LS-Remote documentation  | view source Contained in the perfSONAR_PS-Client-LS-Remote distribution.