 SRB
 Older code base
 Widely accepted across multiple communities
 Core components are tightly integrated
 Globus
 Data transfer components stable
 Control, web service protocols are in flux
 Optional value-added components have varying levels of stability

 SRB
 Proprietary data and control protocol
 Limited documentation available
 Many language bindings
 Globus
 Standards based protocols
GGF
 Grid-ftp
 OGSI, WSRF
 Common underlying communications protocol
 Components are modular and can be mixed together in often arbitrary ways

 SRB
 GUI and command line clients available
 All developed clients must use provided tools
 Simplified central administration
 Globus
 Custom clients need to be designed.
 Multiple entry points, so clients need not be aware of complete system
 Each component has separate administration module

 SRB
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Free software
Easy setup for simple installations
High cost to extend core functionality
Ease of developing clients through multiple tools
Ease of user access through supplied tools
 Globus
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



Free software
Complex setup of multiple disjoint components
Easier to extend core functionality using standard protocols
Clients may be complex due to multiple components
User access is up to grid developer
 Custom portals, registry services

 SRB
 Data access, preservation, management groups
 Groups requiring ease of multiple datasets across administrative and technological boundaries
 Limited to no internal data transformation requirements
 Globus
 Computing and service based needs
 Data components designed to feed into other services and usually not directly accessible to end users
 Data exposed as a service

 SRB
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Single point of contact for support
Mailing lists, bug tracking, online manuals http://www.sdsc.edu/srb
Occasional tutorials at
SDSC
 Globus
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Multiple support groups depending on number of components used
From the Globus Alliance and the Globus community
Manuals, Mailing lists, online tutorials
Numerous seminars and tutorials around the world http://www.globus.org
Commercial support forthcoming (IBM, HP)

 SRB
 Clear text passwords,
GSI authentication
 Central authorization
 Complete separation between underlying operating system and
SRB
 Globus
 GSI authentication
 Authorization depends on local sites and individual components
 Commonly just map
GSI entities to local system users

 SRB
 Srbmasters provide srb specific data moving protocol
 MCAT tracks all available data holdings on srbmasters
 Tight coupling, all available data MUST be registered in MCAT
 Globus
 Gridftp provides extended ftp services
(striping, GSI authentication, etc)
 Data locating handled through RLS
 Not tightly coupled to gridftp

 SRB
 MCAT stores metadata system and descriptive centrally
 Can be queried using SQLlike syntax
 Database pass-throughs can be registered and directly queried with limited output transformation
 Globus
 MCS can track limited descriptive metadata
 OGSI-DAI can provide 3 rd party access to existing data sources
 Not tightly coupled to underlying data on ftp services
 Sepeaation between system and descriptive

 SRB
 Limited remote execution
 Must be registered in
MCAT and application installed on srbmaster
 Cannot execute arbitrary code
 Globus
 Easy to design add on services as web service
 Can tie into existing compute resources
 In hpc manner, many components can execute arbitrary jobs

 SRB
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
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The SRB can easily handle textual metadata.
Extended metadata support requires extensive code modification
SRB needs to be treated as an end to end data grid and not as individual components
 Globus
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Globus is flexible, but also complicated
Some Globus components are fragile (MCS, RFT) while others are very solid and reliable (GSI interfaces, GridFTP)
Globus is evolving and improving: the implementation was made much better with subsequent toolkit releases