Globus C Web Services Core for Developers

Globus C Web Services Corefor Developers

Bill Allcock, ANL

Joe Bester, ANL

GlobusWORLD / GridWORLD

Sep 2006

Sep 2006 GlobusWORLD / GridWORLD 2

Features

Hosting web services written in C and C++ Implementation of WSRF concepts and port

types Type, client, and service bindings generator

from WSDL and XML schemas to C Client APIs and programs


Service Engine/Container

API (globus_service_engine) for processing WS requests within an application Uses HTTP processor in XIO SOAP serializer/deserializer Service loading and invocation

Program for hosting services globus-wsc-container


Service Engine Usage

globus_service_engine_init()

To manage connection usage: globus_service_engine_register_session(),

globus_service_engine_register_process()

For simplicity globus_service_engine_register_start(),

globus_service_engine_register_stop()


WS-Resources

Resource management API create/find/destroy resource

property management

lifetime management

globus_wsrf_core_tools.h includes function

to find resource from EPR used in the

current message


WS-Resource Properties

Property values associated with a type_info for serialization information

Property values may be dynamic callbacks for attempts to get or set the value

Apps can be notified when properties

change Call globus_resource_property_changed() for

dynamic values


Operation Providers

Reuse a port type implementation Resource Properties

Operations

Examples: wsrp:GetResourceProperty

GetResourceProperty operation

wsrl:ScheduledResourceTermination SetTerminationTime operation

CurrentTime, TerminationTime properties


Notification Consumer

Callback-driven notification User has to deal with XML wildcard

messages

Usage: Create Engine (don't forget to start it!) Create Consumer

Returns EPR of Notification Consumer Service

Subscribe via client stubs May be different for some services


Notification Producer

wsnt:NotificationProducer provider Creates notification-related properties

Handles Subscribe/GetCurrentMessage

operations

Creates Topics for Resource Properties

Notification Producer API Create/destroy topics

Change topics

Also: manage producer, subscriptions, etc but provider handles these for you


Service Groups

wssg:ServiceGroup, wssg:ServiceGroupRegistration providers creates wssg-related properties (Entry,

MembershipContentRule)

implements Add operation

service_group API to manage entries add/remove entries

enumerate entries

also: create/destroy service group provider handles these for you


Handler Chains

Handle specific message elements

Called when matching header element is

found

Examples: WS-Addressing

Set attributes when addressing values encountered

Verify all required addressing elements are present

WS-SecureMessage Add attributes for elements to be signed

Add message signatures

Sep 2006 GlobusWORLD / GridWORLD

SOAP Messaging

XML Serialization Handles to/from file, memory, libxml DOM, HTTP

Options to control (de)serialization default NS

xsi:type attribute

c14n

…


Message Attributes

Key-Value pairs When value is set, optional copy and destroy

functions for memory management Default attributes set at engine initialization

(service) or on a client stub Additional attributes used to pass info from

message handlers Example: wsa:To value set by WS-Addressing

handler


Message Attributes (2)

Authentication Options TLS / WS-SecureMessage Credentials to use Message protection Peer subject name

Also: Message timeouts, persistent connections


Bindings Generator globus-wsrf-cgen program

Uses JavaScript-based template language Generates type bindings

Data structures, allocators, deallocators, serializers, etc

Type information for wildcard handling

Generates service module to call service implementation

Generates client stub functions to invoke (remote) operations

Generates Packaging/Makefiles


Resource Property Element<element name="CounterRP">

<complexType>

<sequence>

<element ref="tns:Value"/>

<element maxOccurs="unbounded" ref="rpns0:Topic"/>

<element maxOccurs="unbounded"

ref="rpns0:TopicExpressionDialects"/>

<element ref="rpns1:TerminationTime"/>

<element ref="rpns1:CurrentTime"/>

<element ref="rpns0:FixedTopicSet"/>

</sequence>

</complexType>

</element>


Example Counter Service

<element name="createCounter">

<complexType/>

</element>

<element name="createCounterResponse">

<complexType>

<sequence>

<element ref="wsa:EndpointReference"/>

</sequence>

</complexType>

</element>


Message Definition

<message name="CreateCounterRequest">

<part name="request"

element="tns:createCounter"/>

</message>

<message name="CreateCounterResponse">

<part name="response"

element="tns:createCounterResponse"/>

</message>


Port Type Definition<portType name="CounterPortType"

wsrp:ResourceProperties="tns:CounterRP">

<operation name="createCounter">

<input

message="tns:CreateCounterRequest"/>

<output

message="tns:CreateCounterResponse"/>

</operation>

...

</portType>


C Type Bindingtypedef struct createCounterResponseType_s

{

wsa_EndpointReferenceType EndpointReference;

} createCounterResponseType;

typedef struct createCounterResponseType_array_s

{

struct createCounterResponseType_s *

elements;

int length;

globus_xsd_type_info_t type_info;

} createCounterType_array;


C Type Bindings Functionsglobus_result_t

createCounterResponseType_init(

createCounterResponseType ** inst);

void

createCounterResponseType_destroy(

createCounterResponseType * inst);

struct createCounterType_s *

createCounterResponseType_array_push(

createCounterResponseType_array * array);


C Type Serializer

globus_result_t

createCounterResponseType_serialize(

const xsd_QName * element_name,

const createCounterResponseType * val,

globus_soap_message_handle_t message_handle,

globus_xsd_element_options_t options);

also deserialize, copy, array, contents-only versions.


XML Wildcards (1)

struct globus_xsd_type_info_s

{

xsd_QName * type;

globus_xsd_serialize_func_t serialize;

globus_xsd_deserialize_func_t deserialize;

globus_xsd_init_func_t initialize;

globus_xsd_destroy_func_t destroy;

globus_xsd_copy_func_t copy;

...};


XML Wildcards (2)

typedef struct xsd_any_s

{

globus_xsd_type_registry_t registry;

globus_xsd_type_info_t any_info;

xsd_QName * element;

void * value;

xsd_string_array namespaces;

} xsd_any;


Client Stub Bindingglobus_result_t

CounterPortType_createCounter(

CounterService_client_handle_t handle,

const char * service_endpoint,

const createCounterType * createCounter,

createCounterResponseType **

createCounterResponse,

CounterPortType_createCounter_fault_t *

fault_type,

xsd_any ** fault);

Also with EPR in place of service_endpointAlso non-blocking functionsRequest and response versions


Client Example (1)createCounterType createCounter;

createCounterResponseType *createCounterResponse=NULL;

createCounterType_init_contents(&createCounter);

globus_soap_message_attr_init(&attrs);

globus_soap_message_attr_set(

attrs,

GLOBUS_SOAP_MESSAGE_AUTHENTICATION_METHOD_KEY,

NULL, NULL,

GLOBUS_SOAP_MESSAGE_AUTH_SECURE_MESSAGE);

CounterService_client_init(

&client_handle, attrs, NULL);


Client Example (2)

result = CounterPortType_createCounter(

client_handle,

counter_service_contact,

&createCounter,

&createCounterResponse,

&fault_type,

&fault);

if (result != GLOBUS_SUCCESS) ...

globus_wsrf_core_export_endpoint_reference(

&createCounterResponse->EndpointReference,

"counter.epr",

&wsa_EndpointReference_qname)l


Service Initialization

globus_result_t

CounterService_init(

globus_service_descriptor_t * service_desc)

{

globus_module_activate(

GLOBUS_WSRF_RESOURCE_MODULE);

...

}


Operation Implementation

globus_result_t

CounterPortType_createCounter_impl(

globus_service_engine_t engine,

globus_soap_message_handle_t message,

globus_service_descriptor_t * service,

createCounterType * createCounter,

createCounterResponseType *

createCounterResponse,

const char ** fault_name,

void ** fault)


Service EPR Constructionglobus_service_engine_get_contact(

engine, &endpoint);

epr->Address.base_value =

globus_common_create_string("%s/%s",

endpoint,COUNTERSERVICE_BASE_PATH);

counter_key = xsd_any_array_push(

epr->ReferenceProperties->any);

counter_key->any_info = &xsd_string_info;

counter_key->element = &CounterKey_qname;

counter_key->value = &resource_id;


add operation

globus_result_t

CounterPortType_add_impl(

globus_service_engine_t engine,

globus_soap_message_handle_t message,

globus_service_descriptor_t * service,

xsd_int * add,

xsd_int * addResponse,

const char ** fault_name,

void ** fault)


add implementation

globus_wsrf_core_get_resource(

message, service, &resource);

globus_resource_get_property(resource,

&CounterPortType_Value_rp_qname,

(void **)&counter_value, NULL);

*counter_value += *add

*addResponse = *counter_value;

globus_resource_property_changed(resource, &CounterPortType_Value_rp_qname);

globus_resource_finish(resource);


Generating WSRF Faults

time_t timestamp = time(NULL);

wsrp_ResourceUnknownFaultType_init(fault);

globus_libc_gmtime_r(&timestamp,

&(*fault)->Timestamp);

*fault_name="ResourceUnknownFault";


Performance Snapshot (GT 4.0.1)

No Security X.509 Signature HTTPS0

20

40

60

80

100

120

140

160

180

200

10.05

181.96

11.462.34

14.8

2.85

25.57

140.5149.67

17.1

0

55.6

8.23

81.39

12.91

Get Resource Property (LAN)

GT4-Java

GT4 - C

pyGridWare

WSRF::Lite

WSRF.NETTim

e (

ms)


Use Case: globusrun-ws Command-line client to submit and monitor WS-GRAM

jobs Interacts with WS-Delegation, WS-GRAM, and

(indirectly) RFT Includes a service engine to handle notification

messages from WS-GRAM On the order of 20x faster than the Java client program

Largely due to the JVM startup costs


Use Case: RFT Client Command-line client to RFT service

RFT performs reliable 3rd-party transfers using GridFTP

Create a transfer, start & monitor it Monitoring via WS-Notification Adds features, improves performance over previous

java client

Meet Ravi:

9/14 11:30 AM "Globus RFT for Developers"


Use Case: GridFTP Resource Properties

Experimental GridFTP feature Server exposes state via resource

properties Server load Connection limits

Acts as WS-MDS provider


Use Case: Container on an ARM processor

Prototype for ocean floor sensor platform for the LOOKING project

Port of C WS Core to proprietary embedded operating system Development board with 4MB Flash, 16MB

RAM NET+OS

C Container statically linked with OS and services


Use Case: Core Command-Line tools Substitute for Java CLI tools in 4.1, 4.2 Clients work with any service implementing

the related port types WS-ResourceProperties

globus-wsrf-query globus-wsrf-get-property globus-wsrf-get-properties globus-wsrf-insert-property globus-wsrf-update-property globus-wsrf-delete-property


Use Case: Core Command-Line tools

WS-ResourceLifetime globus-wsrf-destroy globus-wsrf-set-termination-time

WS-BaseNotification globus-wsn-get-current-message globus-wsn-pause-subscription globus-wsn-resume-subscription globus-wsn-subscribe


Project Web Page / Contributions http://dev.globus.org/wiki/C_WS_Core Globus is largely following the Apache project

model at this point. We would welcome contributors.

Long term, high quality contributors can be voted in as committers.

An alternative would be to start a new, independent project that utilized C WS Core, on which you could be a committer at the start.


Getting help / more information Email lists

cwscore-[dev|user|announce]@globus.org

Documentation http://www.globus.org/toolkit/docs

Bugzilla http://bugzilla.globus.org/bugzilla Product is C WS Core

HPDC Paper http://www.globus.org/alliance/publications/papers/

WSRFComparison2005-3.pdf Comparison of five different WSRF implementations


Futures

More clients (delegation, ...) Improved container

More core services (registry, secure conversation, …)

More flexible container configuration

Authorization Improvements Persistent services Update to newer web standards Your C based Web service or client?


Meet the Developers Session at Globus Alliance Booth (152A-P7)

September 12

8:00am - 9:00am "Java WS Core and Security (C, Java)" -- Olle Mulmo, Jarek Gawor, Rachana Anantakrishnan

11:30am -12:30pm "RLS" -- Rob Schuler, Ann Chervenak12:30pm -1:30pm "MDS" -- Mike D'arcy, Laura Pearlman3:00pm - 4:00pm ”Resource Management (GRAM, Virtual Workspaces and Dynamic Accounts)" – Stu Martin, Peter Lane, Tim Freeman, Kate Keahey6:00pm - 7:00pm "C WS Core" -- Joe Bester7:00pm - 8:00pm "Python WS Core" -- Joshua Boverhof

September 13

8:00am - 9:00am "GridShib" -- Von Welch, Ton Scavo, Tim Freeman

11:30am - 12:30pm "GT Installation and Administration" -- Charles Bacon12:30pm - 1:30pm "MyProxy" -- Jim Basney3:00pm - 4:00pm "GridFTP, XIO, RFT" -- John Bresnahan, Ravi Madduri


Say YES to Great Career OpportunitiesSOFTWARE ENGINEER/ARCHITECTMathematics and Computer Science Division, Argonne National LaboratoryThe Grid is one of today's hottest technologies, and our team in the Distributed Systems Laboratory (www.mcs.anl.gov/dsl) is at the heart of it. Send us a resume through the Argonne site (www.anl.gov/Careers/), requisition number MCS-310886.

SOFTWARE DEVELOPERS

Computation Institute, University of Chicago Join a world-class team developing pioneering eScience technologies and applications. Apply using the University's online employment application (http://jobs.uchicago.edu/, click "Job Opportunities" and search for requisition numbers 072817 and 072442).See our Posting on the GlobusWorld Job Board or Talk to Any of our Globus Folks.

Question: Do you see a Fun & Exciting

Career in my future?

Magic 8 Ball: All Signs Point to YES

Globus C Web Services Core for Developers

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