perfsonar client construction
DESCRIPTION
February 11 th 2010, APAN 29 – perfSONAR Workshop Jeff Boote, Assistant Director R&D. perfSONAR Client Construction. Outline. Motivation Types of Client Interaction Echo MA MetadataKeyRequest SetupDataRequest LS XQuery Discovery API Tour. Motivation. - PowerPoint PPT PresentationTRANSCRIPT
perfSONAR Client ConstructionperfSONAR Client Construction
February 11th 2010, APAN 29 – perfSONAR WorkshopJeff Boote, Assistant Director R&D
• Motivation• Types of Client Interaction
– Echo– MA
• MetadataKeyRequest• SetupDataRequest
– LS• XQuery• Discovery
• API Tour
2 – 04/21/23, © 2009 Internet2
Outline
• Development of client applications is crucial to the success of perfSONAR– External applications will consume the measurement data– Researchers will find new users for performance measurements
through client applications• Client development requires knowledge of:
– Service operation– Framework interaction– Available APIs– Data formats
3 – 04/21/23, © 2009 Internet2
Motivation
• There are different types of client interaction– Echo Request
• Check the ‘liveness’ of a service
– MA Specific Messages• MetadataKeyRequest
– Request a replayable ‘key’ to get measurement data
• SetupDataRequest– Request measurement data
– LS Specific Messages• Xquery
– Raw interface to LS databaes – using the XQuery interface
• Discovery– Structured discovery queries
4 – 04/21/23, © 2009 Internet2
Types of Client Interaction
• The Echo request is a simple message that checks to be sure a service is ‘alive’.
5 – 04/21/23, © 2009 Internet2
Echo Request
• Client must be prepared to:– Communicate with services using SOAP over HTTP– Send a request message to a given service URL– Parse the XML response from the service– Record the results of the Echo
• Success in the form of an EchoResponse• Failure in the form of an EchoResponse• Service timeout• Alternate response (anything but an EchoResponse message should
be viewed as a failure)
6 – 04/21/23, © 2009 Internet2
Echo Request
7 – 04/21/23, © 2009 Internet2
Echo Request
8 – 04/21/23, © 2009 Internet2
Echo Request
• The MA derived services have two messages that are interest to client applications:– MetadataKeyRequest
• Given a (partial) metadata description, the service will check if this exists in the database
• If it does exist, return a replayable ‘key’ to have a fast access to measurement data
– SetupDataRequest• Given a (partial) metadata description, the service will check if this
exists in the database• If it does exist, return measurement data
9 – 04/21/23, © 2009 Internet2
Measurement Archive
10 – 04/21/23, © 2009 Internet2
MetadataKeyRequest
11 – 04/21/23, © 2009 Internet2
MetadataKeyRequest
12 – 04/21/23, © 2009 Internet2
MetadataKeyRequest
13 – 04/21/23, © 2009 Internet2
MetadataKeyRequest
14 – 04/21/23, © 2009 Internet2
MetadataKeyRequest
15 – 04/21/23, © 2009 Internet2
SetupDataRequest
16 – 04/21/23, © 2009 Internet2
SetupDataRequest
17 – 04/21/23, © 2009 Internet2
SetupDataRequest
18 – 04/21/23, © 2009 Internet2
SetupDataRequest
19 – 04/21/23, © 2009 Internet2
SetupDataRequest
20 – 04/21/23, © 2009 Internet2
SetupDataRequest
21 – 04/21/23, © 2009 Internet2
SetupDataRequest
• Each message has the ability to apply what is called a ‘filter’. • Filters are a way to limit the returned data set:
– By Time– By Type (e.g. in the case of RRD data select which ‘consolidation
function’ is applied)• Filters are applied to a metadata in the message by using the ID
fields
22 – 04/21/23, © 2009 Internet2
Measurement Archive
23 – 04/21/23, © 2009 Internet2
Measurement Archive - Filtering
• Different measurement archives will have different metadata formats– SNMP MA
• Layer 3 Interface description– perfSONAR BUOY
• Endpoint pair (2 Layer 4 hosts)– PingER
• Endpoint pair (2 Layer 4 hosts)– Status MA
• Layer 3 or Layer 2 Interface description
• Consult the protocol and service documentation for specific formats
• Your client should be prepared to parse the XML to find useful information
24 – 04/21/23, © 2009 Internet2
Measurement Archive
• Client must be prepared to:– Communicate with services using SOAP over HTTP– Send a request message to a given service URL– Parse the XML response from the service
• Be prepared to deal with key elements• Understand the data format of the returned measurement data
– In the event of an error:• Interpret a result code from the service• Fail gracefully
25 – 04/21/23, © 2009 Internet2
Measurement Archive Requests
• The gLS and hLS have two messages that are interest to client applications:– LSQueryRequest (XQuery Based)
• The metadata subject will contain an XQuery statement• The XQuery will be applied to the Lookup database. • The success or failure will be passed back
– LSQueryRequest (Discovery Based)• A well formed metadata block will contain items to search for
– Domains– Keywords– IP Ranges– Data Types
• The summary database will be consulted• A list of services to consult further (either hLSs or services depending
if you asked at the gLS or hLS layer) will be returned
26 – 04/21/23, © 2009 Internet2
Lookup Service
27 – 04/21/23, © 2009 Internet2
Lookup Service
28 – 04/21/23, © 2009 Internet2
Lookup Service
29 – 04/21/23, © 2009 Internet2
Lookup Service
30 – 04/21/23, © 2009 Internet2
Lookup Service
31 – 04/21/23, © 2009 Internet2
Lookup Service
32 – 04/21/23, © 2009 Internet2
Lookup Service
33 – 04/21/23, © 2009 Internet2
Lookup Service
34 – 04/21/23, © 2009 Internet2
Lookup Service
• There are several client APIs available in the perfSONAR-PS packages:– perfSONAR_PS::Client::Echo
• Package for performing echo tests against services
– perfSONAR_PS::Client::MA• Package for contacting any MA using general calls
– perfSONAR_PS::Client::PingER• Package for interacting with PingER servers
– perfSONAR_PS::Client::LS• Package for contacting the LS infrastructure, could be used for hLS or
gLS
– perfSONAR_PS::Client::gLS• Package for contacting the gLS infrastructure, could also be used to
contact hLS instances
35 – 04/21/23, © 2009 Internet2
API Tour
perfSONAR Client ConstructionperfSONAR Client ConstructionFebruary 11th 2010, APAN 29 – perfSONAR WorkshopJeff Boote, Assistant Director R&D
For more information, visit psps.perfsonar.net
36 – 04/21/23, © 2009 Internet2
• Module designed to send a simple EchoRequest to a given service
• Object Oriented• Built in use of:
– SOAP over HTTP transport– XML Parsing– Evaluation of result codes for success or failure
• More information available via perldoc
37 – 04/21/23, © 2009 Internet2
perfSONAR_PS::Client::Echo
38 – 04/21/23, © 2009 Internet2
perfSONAR_PS::Client::Echo
• Module designed to send a generic MetadataKey/SetupData requests to services
• Object Oriented• Built in use of:
– SOAP over HTTP transport– XML Parsing– Support for error codes
• General construction accepts XML for subjects– Requires that clients have knowledge of the service they are
contacting• Returns XML (metadata and data) in perl objects
– Requires clients to parse out much of the meaning• More information available via perldoc
39 – 04/21/23, © 2009 Internet2
perfSONAR_PS::Client::MA
40 – 04/21/23, © 2009 Internet2
perfSONAR_PS::Client::MA
• Module designed to send queries to PingER services• Object Oriented• Built in use of:
– SOAP over HTTP transport– XML Parsing– Support for error codes
• General construction accepts XML for subjects• Returns structured objects that contain data• Used in several GUI applications• More information available via perldoc
41 – 04/21/23, © 2009 Internet2
perfSONAR_PS::Client::PingER
42 – 04/21/23, © 2009 Internet2
perfSONAR_PS::Client::PingER
• Module designed to query (and perform other operations) on LS type services– Works with gLSs and hLSs
• Object Oriented• Built in use of:
– SOAP over HTTP transport– XML Parsing– Support for error codes
• Main query mechanism is to support arbitrary XQuery statements– Requires knowledge of XQuery to be effective
43 – 04/21/23, © 2009 Internet2
perfSONAR_PS::Client::LS
44 – 04/21/23, © 2009 Internet2
perfSONAR_PS::Client::LS
• Module designed to query gLSs, namely the discovery component– Will work on the summary set of an hLS also
• Object Oriented• Built in use of:
– SOAP over HTTP transport– XML Parsing– Support for error codes
• Supports both raw (XQuery type) operation as well as discovery queries:– IP Addresses– Domains– Data Types– Keywords
45 – 04/21/23, © 2009 Internet2
perfSONAR_PS::Client::gLS
46 – 04/21/23, © 2009 Internet2
perfSONAR_PS::Client::gLS
47 – 04/21/23, © 2009 Internet2
perfSONAR_PS::Client::gLS – cont.
perfSONAR Client ConstructionperfSONAR Client ConstructionFebruary 11th 2010, APAN 29 – perfSONAR WorkshopJeff Boote, Assistant Director R&D
For more information, visit psps.perfsonar.net
48 – 04/21/23, © 2009 Internet2