Globus Computing Infrustructure
Software
Globus Toolkit
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Grid computer software infrastructure
• Primary objective: to makes a seamless
environment for users to access distributed
resources.
• Key aspects:
– Secure envelope – over all transactions
– Single sign-on – being able to access all available
resources after providing credentials ONCE
– Data Management
– Information services - providing characteristics of
resources and their status (including dynamic load)
– APIs and services that enable applications themselves
to take advantage of Grid platform
– Convenient User Interfaces
(??)
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Globus Project
• Open source software toolkit developed for Grid
computing.
• Roots in I-way experiment – led by Ian Foster
• Work started in 1996.
• Now up to Version 5
• Reference implementations of Grid computing
standards.
• Defacto standard for Grid computing and one of
the most influential projects
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Globus Toolkit
• “Toolkit” of services and packages for
creating basic grid computing
infrastructure. One may use parts of the
toolkit as needed.
• Five major parts:
– Common run time - Libraries and services
– Security - Components to provide secure access
– Execution management - Executing, monitoring and
management of jobs
– Data Management - Discovery access and transfer of data
– Information - Discovery and monitoring of resources and
services
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Globus Toolkit Version
• Version 1 essentially a research prototype not widely used
• Version 2 widely used - not web-service based
• Version 3 web service based but not widely accepted because
of the way services were implemented and non-robustness
• Version 4 is web-service based. Some non-web services code
exists from earlier versions (legacy) or where not appropriate
to change to web-service based (for efficiency, etc.).
• Version 5 returned to non-web service approach of version 2.
• We are using Globus Version 4.0 as it is mature, widely used,
and we did not want to incur new software problems in class.
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Timeline of Globus Toolkit
Globus 5.0.4
Globus 5.0.0
2011
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Globus Open Source Grid Software Version 4
G
T
4
G
T
3
G
T
2
G
T
3
G
T
4
Community
Scheduler
Framework
[contribution]
Delegation
Service
Python WS Core
[contribution]
C WS Core
Community
Authorization
Service
OGSA-DAI
[Tech Preview]
WS
Authentication
Authorization
Reliable
File
Transfer
Grid
Resource
Allocation Mgmt
(WS GRAM)
Monitoring
& Discovery
System
(MDS4)
Java WS Core
GridFTP
Grid
Resource
Allocation Mgmt
(Pre-WS GRAM)
Monitoring
& Discovery
System
(MDS2)
C Common
Libraries
Pre-WS
Authentication
Authorization
Web
Services
Components
Non-WS
Components
Replica
Location
Service
XIO
Credential
Management
Security
Data
Management
Execution
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Management
Information
Services
Common
Runtime
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I Foster
Major Globus 5 changes over
version 4
“Most components of GT5 are incremental updates
(numerous bug fixes and new features) over their
GT4 counter-parts (e.g. GridFTP, RLS, MyProxy, GSIOpenSSH”
Some components taken out: GT4 Java Core, WSGRAM4, RFT, to be replaced.
GRAM implementation -- pre-WS GRAM2 code base
and GRAM2 compatibile.
NO WEB SERVICE COMPONENTS
http://www.globus.org/toolkit/docs/5.0/5.0.0/rn/
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Currently not showing information services in version 5.
New Globus crux project will address this.
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http://www.globus.org/toolkit/about.html
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Some basic Globus components
• GSI Grid Security Infrastructure
– Provides for security envelop around Grid resources
– Uses public key cryptography
• GRAM (Globus/Grid Resource Allocation
Management)
– Globus’ basic execution management component
– Used to issue and manage jobs
• GridFTP
– For transferring files between resources
• MDS (Monitoring and Discovery Service)
– To discover resources and1-2their status
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Security Issues
• Has to cross administrative domains.
• Need agreed mechanisms and
standards.
• Focus on Internet security
mechanisms, modified to handle the
special needs of Grid computing.
• Distributed resources must be
protected from unauthorized access.
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GSI (Grid Security Infrastructure)
Globus components for creating security envelop
• Requires each user to be authenticated (their
identity proved)
• Uses public key cryptography (basis of Internet
security)
• Each user must possess a (digital) certificate, signed
by a trusted certificate authority.
• Users will also need to be able to give their authority
to Grid components to act on their behalf – so-called
proxy certificates, see later.
• Users generally will also need accounts on resources
they intend to use (authorization).
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Resource Discovery
Globus MDS (Monitoring and
Discovery System)
• Still primitive and in research but
ideal is to be able to submit a job
and the system find the best grid
resources for that job across the
whole grid
• Users might access MDS to discover status of
compute resources. In practice, users often know
what resources are there but not dynamic load.
• MDS might be used by other Grid components such
as schedulers.
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Executing a Job
GRAM (Globus or Grid Resource Allocation
Management)
• Users typically want to submit jobs
for execution.
• Grid computing environments mostly
Linux-based and originally and still
commonly accessed through a
command line.
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Job submission command-line
interface
•Once you have established your security credentials,
to run a simple job you might issue GRAM command:
globusrun-ws -submit -c prog1
*
where prog1 is executable of job.
•Executable needs to be present on compute resource
that is to execute it.
•Above command does not specify compute resource
and hence computer executing globusrun-ws command
will execute prog1.
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* Globus 5 command is globusrun (not a web service)
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GridFTP command to transfer files
globus-url-copy \
gsiftp://www.coitgrid02.uncc.edu/~abw/prog1out \
file:///home/abw/
First argument -- source location
Second argument -- destination location.
In the above case, the file:
www.coit-grid02.uncc.edu/~abw/prog1out
transferred to
home/abw/prog1out
on the local computer.
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Scenario of User employing Globus
services and facilities
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Grid portals
• Command-line interface a very primitive way of
interacting with Grid resources.
• Portal offers a higher-level Web based interfaces to
accessing and controlling grid resources and to
communicate with other members of Virtual
Organization
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Gridsphere
• Gridsphere is a toolkit to build a portal
• We are starting with a portal. Next we will use
the command line
• Later we will have an assignment of building a
portal
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Proxies
• To use many services, you are required to have a
proxy certificate (a proxy), derived from your user
certificate.
• Proxies enables resources to be accessed on user’s
behalf.
• Proxies are part of Grid security infrastructure,
discussed later in course.
• A credential management service called myProxy is
used to hold proxies
• Usually, Gridsphere automatically obtains a proxy
from the myProxy server for you when you log in.
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Proxy management tab
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Questions
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Quiz
Question: What is meant by "single sign-on"?
(a) Allowing only one person to sign onto a
computer
(b) Not allowing a person to log onto a computer
more than once in any one period
(c) A mechanism in which a user does not need to
sign again to acquire additional resources.
(b) None of the other answers
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Question: What is authentication and
what is authorization? What’s the
difference?
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Question: What does GRAM do?
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Question: What does MDS do?
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Question: What compoent in the Globus
toolkit provides the means to transfer
files?
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Discussion Question
Is it possible to use the tradition security
method of username/password on a grid?
What problems exist for this method?
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