SCI-BUS is supported by the FP7 Capacities Programme under contract nr RI gUSE Services Remote API, DCI Bridge, Data Bridge, Robot Certificate Zoltán Farkas, Péter Kacsuk, Gábor Herman, István Márton, Tibor Gottdank, Ákos Balaskó MTA SZTAKI LPDS

Outline Remote API DCI Bridge Data Bridge Robot Certificate

REMOTE API

Goals - Solutions Submitting a WS-PGRADE/gUSE workflow using an HTTP client without the web interface of WS-PGRADE Solution: The Remote API web service extension of gUSE will be used as application layer in order to communicate with the backend (gUSE) instead of WS- PGRADE portlets The workflows to be submit should be available at the caller – As WS-PGRADE workflow definitions contain own set of input files, reference to input files must be changed, but the files of job executable, and the command line parameters can be changed as well Solution: Manual change of files to be replaced and the creation of new association table (coded in the „portmapping.txt” file). The main workflow descriptor file.xml should be modified only in the case when command line parameters belonging to the individual nodes (jobs) of the workflow must be modified On completion of a workflow submission session the common resources should be cleared Solution: The servers side data belonging to the workflow (submission) will be cleared upon the successful execution of the „Get output” command of the client

Typical workflow development scenario in case of remote call WS PGRADE SERVER 1 Portal gUSE DCI Bridge.xml.zip portmapping.txt HTTP Client Copy (modify) Upd. user files Copy and rename Eventual update Set of computational resources WS PGRADE SERVER 2 Portal gUSE Remote API Serv. DCI Bridge Browser GRAPH Ed Orig user files 1.Create and submit original workflow.zip.xml tree of files 2. Download tested workflow 3. Reengineering of wf definition 4. Submit the modified workflow Client side Server side

Summary of workflow development and remote submission process 1.Download the original workflow from WS-PGRADE 2.Do some reengineering: separate the structure description from the other parts explore the user defined (not channel) input files connected to the numbered ports of the named jobs and the files of executable of the named jobs Pack the needed files together and create a text file which describes the association of the files and the named jobs and ports 3.Create the needed script files needed to habitual submission process (call, observe, download (delete)) 4.Execute the scripts on the client machine

Basic assumptions of remote call setup There is a working gUSE set of services where the Remote API Servlet extension has been installed There is a client machine containing the description (structure, input files) of a workflow The client can reach the server by the HTTP protocol There is a server-created password known by the client(s) The client has the necessary proxy certificate file if the submissions involved in the workflow are directed to such resources which need certificate bound authorization *(see installation file and documentation on Sourceforge for version : Code: /remote-3.4.tgz/download remote-3.4.tgz/download Documentation: /Documentation/RemoteAPI_Install_Manual.pdf/do wnload Documentation/RemoteAPI_Install_Manual.pdf/do wnload )

DCI Bridge

What is DCI Bridge - 1 A web service based application that provides standard access to various distributed computing infrastructures (DCIs), such as: grids, desktop grids, clusters, clouds and service based computational resources (connecting through its DCI plugins to the external DCI resources). Supported DCIs

When a user submits a workflow, its job components can be submitted transparently into the various DCI systems using the OGSA Basic Execution Service 1.0 (BES) interface. As a result, the access protocol and all the technical details of the various DCI systems are totally hidden behind the BES interface. The standardized job description language of BES is JSDL. What is DCI Bridge - 2 Generic View From gUSE or independently (from other workflow systems) can also use DCI Bridge for job submission

Administration Interface – 1 A sample view of Middleware settings page.

Submenu nameFunctionality Add newA new resource reference can be named and added to the group EditAn existing resource can be selected and its access attributes can be modified MonitorObservation of jobs belonging to the given resource group Middleware settingsSet of generic parameters common in the given middleware Log entriesOpens the history log where the main user activities of the Administrator can be traced. Submenu nameFunctionality ManagerThe general flow of jobs can be enabled or disabled in the Manager submenu. SettingsIt contains properties for generic settings. Log entriesOpens the history log where the main user activities of the Administrator can be traced. Base Menus Middleware Menus Administration Interface – 2

The job flow in the DCI Bridge and between the components. WFI generates and submits the jobs' JSDL to the DCI-BRIDGE. plugins Plugins Architecture

DCI Bridge Admin Interface (JSP pages) Semi-autogenerated Eventhandlers BES Middleware Brokering and Management Layer (Plugin Manager) Unicore gLite GT2 GT4 CB PBS Local... GT5 Middleware Class local dci-bridge host(64bit) 0 JSDL Processing DCI Bridge accepts standardized JSDL job description documents. These documents are based on a well-defined XML scheme containing information about the job inputs, binaries, runtime settings and output locations. DCI Bridge WS-PGRADEWFI JSDL

WFI Job Processing DCI BRIDGE DCI WFS Storage PLUGIN WFI requests configuration data for job submission from WFS. From response WFI creates a JSDL 1 JSDL WFI sends JSDL to DCI Bridge 2 DCI Bridge gets inputs from Storage 3 PLUGIN submits the job together with inputs to a DCI, monitors the job status and gets the outputs. 4 DCI Bridge sends outputs to the Storage 5 DCI Bridge sends back job status to WFI. 6

Steps of Plugin Creation Developing middleware specific parts Implementing of 4 methods: submit (invoked on job submission; performs job submission getStatus (invoked when job status need to be queried; queries job status and sets job status accordingly abort (invoked when the job need to be aborted; aborts the execution of the job) getOutputs(invoked when the outputs of the job need to be downloaded; downloads the outputs to a local folder)

Steps of Plugin Creation – 2 2.Developing configuration interface on DCI Bridge 2.1 Adding new middleware name in mb_scheduling_description_language.xsd (other fields relevant for resource (VO, DCI) selection are generic) ….. New Mid dleware

Steps of Plugin Creation Extending existing classes that process tab/menu selection logic 2.4 Creating JSPs 2.2 Extending configuration schema with middleware-specific configuration possibilities in dci-bridge_configuration_schema_2012.xsd

Steps of Plugin Creation - 4 New middleware WS-PGRADE Creating new class (JobConfigUI_newm id) Implementing the getJsp and the getJobParameters methods. Modification in WFI: Modify the JobConfig class: Adding the new middlewares name in mbsdlMiddleware() method (it maps the job's configuration to the middlewares configured in DCI-Bridge). 3.Developing WS-PGRADE and WFI specific parts

DATA BRIDGE

Outline Problem statement Data Bridge as independent DCI service: – Data Bridge concept – Use-cases – Data Bridge architecture WS-PGRADE integration – Data browsing portlet gUSE integration

Problem statement Scientific applications: – Individual jobs or workflows – Access data from diverse sources – Science Gateways can hide the details, but… Data sources: – Diverse types: HTTP, FTP, GridFTP, SRM, iRODS, … – Thus, different APIs are needed to access these One possible solution is to use a service that can be used to access the sources through a unified interface

Data Bridge Offers a simple service that provides a generic interface above different DCI's storage services to handle the data stored The service in different use cases offers a way to browse, upload and download data, and with the help of multiple server instances it enables inter- DCI data transfer as well

Use cases Use case 1: Browse a single DCI data storage from WS-PGRADE, upload data Use case 2: Transfer data files between different DCIs Use case 3: Fetch input data on a DCI worker node from an other DCI Use case 4: Cloud storage usage

Use case 1: Storage browsing and data upload WS-PGRADE Storage Browsing Portlet Data Bridge Adaptor Interface Storage Adaptor Storage Browse and upload

Use case 2: Data Transfer – Using multi- level Data Bridge Data Bridge Adaptor Interface Storage 1 Storage 2 Data Bridge Adaptor Client: Storage Browsing Portlet Custom application … Data Bridge Adaptor Interface Storage Adaptor 2 Storage Adaptor 1

Use case 3: Fetch data on a DCI’s worker node from a „foreign” DCI’s storage Data Bridge Adaptor Interface Storage Adaptor Storage DCI Worker node Wrapper Pre-process Executable Post-process Data bridge usage guidelines: – First try to fetch the data using native tools – Only if this fails, use the Data Bridge

Use case 4: Cloud Storage access from WS-PGRADE/gUSE Currently, no S3 support in WS-PGRADE An S3 Data Bridge adaptor would fix this WS-PGRADE/gUSE DCI Worker node Amazon S3 Data Bridge Job

Data Bridge Architecture Public Interface Adaptor Manager Worker Pool Thread 1 Thread 2 Thread n Adaptor Interface DCI Adaptor 1 DCI Adaptor 2 DCI Adaptor 3 DCI Adaptor m jSAGA Temporary URL queue HTTP servlet URI

Data Bridge components Interfaces: – Public Interface – Adaptor Interface Adaptor Manager Worker Threads DCI Adaptors

Data Bridge components- Interfaces Public Interface: – Provides the public interface for external components (Portlets, gUSE, …) – Web Service interface Adaptor Interface: – A Java interface that hides the details of the different adaptors

Data Bridge Public Interface Operations: – List – Mkdir – Delete – Get – Put – Copy – Move Entities: – URI (either a path, an URL or some specific class) Error reports: – Common exceptions

Data Bridge Public Interface - URI Represents an element with a given URI (a directory, a file, metadata attributes, …) Also needs to carry security credentials (if needed) Attributes: – Nothing special in the base class – For gLite, e.g: Path: the full path Type: directory or file Size: length of the entity (0 for directories) Attributes: optional, contains information as returned by the Adaptor Interface's Stat function

Data Bridge Public Interface – Get and Put Two-phase up- and download with the temporary URL queue: First, the web service interface is invoked to register the transfer request Next, a simple HTTP client may use HTTP GET or POST/PUT to down- or upload the data This way, web service invocation („heavyweight” SOAP) is separated from data transfer („lightweight” HTTP) Public Interface Adaptor Manager Worker Pool Thread 1 Thread 2 Thread n Adaptor Interface DCI Adaptor 1 DCI Adaptor 2 DCI Adaptor 3 DCI Adaptor m Temporary URL queue HTTP servlet URI

Adaptor Manager and Worker threads Provided by JAX-WS web service API Tasks: – Manage incoming requests – Initialize worker threads to perform the requested operation – With the help of different adaptors

DCI Adaptors Implement: Adaptor Interface Tasks: – Perform operations requested by the Worker Threads, that is operations invoked through the web service Types: – gLite (using jSAGA) – GridFTP (using jSAGA) – FTP (using jSAGA) – … – Data Bridge: special adaptor to forward requests to other Data Bridges

Data Bridge clients Web Service clients: – Create your own based on the WSDL (or REST) Java API: – Provides a convenient tool to use Data Bridge Public Interface functions – Data transfer functions should accept InputStream and OutputStream objects as their arguments

WS-PGRADE integration A Data Browsing portlet that eases storage management

WS-PGRADE Workflow I/O configuration During a workflow node's IO configuration the user should be able to select files from storages The provided interface should be the same as the selected storage's Storage Browsing portlet (only with one panel)

Current status, future work Core Data Bridge (available as a web service) ready, working with most major protocols (FTP, GridFTP, SRM) User Interface development has been started, first version will be available as part of WS- PGRADE/gUSE shortly

ROBOT CERTIFICATE

The concept of robot certificates The normal certificate is used to identify users The robot certificate is used to identify applications As a consequence the application should be trusted When the CA provides the certificate for the application, the certificate contains the identifier of the person or organization that validated the application and takes the responsibility for it It is the policy of the user community and the CA to decide whose name should be in the certificate 42

EGI VO Portal Policy I. ● The Portal, the VO to which the Portal is associated, the Portal manager are all individually and collectively responsible and accountable for all interactions with the Grid, unless a credential of a Strongly Identified Web User is used to interact with the Grid ● The Portal must be capable of limiting the job submission rate ● The Portal must keep audit logs for all interactions with the Grid (

EGI VO Portal Policy II. ● Portal classes (in fact, these are working mode classes, i.e. the same portal can be in parameter mode from the point of view of a certain user and in the same time can be in job management mode from the point of view of another user): SZTAKI gUSE

EGI VO Portal Policy III. ● Robot certificates can be used only for the first 3 working modes of the portal ● Job management mode portals/applications must not use robot certificates

SCI-BUS portals and EGI According to the EGI classification : – WS-PGRADE/gUSE is a portal that can be used in 1,2,3,4 modes – The community portals could also work in any of the 4 modes depending of the needs of the corresponding user community – Robot certificates are needed only for the 1,2,3 modes 46

Relationship between robot certificates and WF applications in WS-PGRADE/gUSE The WF applications can have different robot certificates Even the jobs within a workflow can have different robot certificates (this enables that different jobs of a WF can be executed in different DCIs requiring different robot certificates) This robot certificate contains the name of the community who set up the gateway Example: – Autodock gateway set up by SZTAKI and UoW – The robot certificate will contain the name: SCI-BUS 47

WS-PGRADE/gUSE extensions to support robot certificates The robot certificates should be hidden for the end-users but manageable for the portal developer/administrator The WF applications with robot certificates will be stored in the internal repository of gUSE Consequences: – The internal repository should be extended to be able to store the identification of the robot certificates for every node – The portal developer/administrator (with a new privileged role to be introduced besides the power and end-user roles) should be able to assign the robot certificates for the WF nodes 48

Suggested process to assign robot certificates to WF nodes When a WF is tested and ready to use in the community portal the next step is to assign robot certificates to the nodes of the WF This will happen in the following way: 1.Portal developer imports the WF from the internal repository 2.Use the WF configuration facility of WS-PGRADE (this will be extended to enable the definition of robot certificates, see next slide) 3.Test the workflow with the assigned robot certificates 4.Export the WF with assigned robot certificates into the internal repository Notice that some nodes of the WF can work with robot certificates while other nodes require user certificate. Therefore even during the execution of a WF the portal can change among working modes. 49

UI extension to assign robot certificates to WF nodes 50 + line (robot cert opt) + checkbox + auto ModWin

Usable Certificate types X509 and Myproxy: A: B: DN and HOST cert Unicore : A: B: User’s own assertion CloudBroker Platform: A: B: User’s own user/pass PBS or LSF cluster: A: Generating new key B: User’s own key *

Storing the robot certificate for a given job When the portal developer saves the WF that contains Job A with robot certificate the following happens: – The portal stores Job A with the required robot certificate at a secure position. This stored job bundle will get a job bundle identifier – In the configuration of Job A this identifier will be add the original configuration information – When the workflow is saved to the repository this new extended configuration field (containing the Job A bundle identifier) will be saved 52

Job Bundle structure Binary (executable) Robot certificate parameters (depending on the middleware type). This could be: – Login/password (e.g. PBS, cloud) – Certificate access information (e.g. gLite, GTx) 53

Execution of a WF with robot certificates When the WFI interprets Job A with the robot certificate it will place into the JSDL the Job A Bundle identifier, too When the DCI Bridge receives a job with a bundle identifier, it: – Goes to the Bundle service and asks all the information related to this bundle – If the security information is a certificate access, then goes to the credential provider service (in WS-PGRADE) by passing the certificate access information as input and gets back a certificate proxy 54

Further requirements for gUSE to provide Suitable log to identify the person who submitted a WF with robot certificate Restriction of the number of jobs submitted to a certain VO during a certain time period 55

Suitable log to identify the person who submitted a WF Each logged event must contain: – A timestamp – The portal user’s ID – The portal user’s IP Job submit event should contain: – WF’s name – Job’s name – Job’s PID (in case of parametric jobs) – Job’s DCI Bridge ID – Credential used (proxy DN, username, …) – Input file list with sizes – Grid ID in case of successful submission – Error message in case of job submission failure These are already stored in DCI Bridge (see next slide)

Suitable log to identify the person who submitted a WF Job status change events should contain: – The job’s DCI Bridge ID – The job’s new status – Optionally: the job’s old status Terminal job status events should contain: – Outcome (success, failure, with exit code) – List and size of output files transferred

Log information in DCI Bridge After completing a job a zip file is created identified by the job identifier and containing all the information of the previous slide. This contains 3 files: – DCI Bridge log – JSDL – Log created in the DCI resource We will store these zip files in a temporary storage area but archiving them will be the responsibility of the portal admin 58

Restriction of the number of jobs submitted to a certain VO This information will be stored in the DCI Bridge This is a parameter configurable by the portal admin for each DCI VO This information should be given when the robot certificate is assigned to a certain a job 59