1. Interface of “The Grid” to “The Fabric” Rich Baker Brookhaven National Lab

2. 10/1/2016 CHEP 03, California 2 Outline  Overview & Definitions  Fabric vs. Middleware?  Fabric vs. Grid?  Refocus the Debate?

3. 10/1/2016 CHEP 03, California 3 What are Middleware & Fabric? Applications High Level Grid Services Expose Abstract Services Middleware View (Multiple Implementations of) Concrete Services Fabric Administrative Domain – Security and Site Policy Operating Systems, Batch Queues, File Systems Physical Storage, CPU, Network, etc. Gray Area?

4. 10/1/2016 CHEP 03, California 4 Why Is There “Gray Area?”  Multiple Layers of Fabric  Chip Set, Physical Disks, Raw Hardware  Operating Systems, File Systems  Batch Queues  Site Administration Tools  Policy, Security  Multiple Layers of Middleware  Low Level Services Used by Higher Level Services  Some Push to Reimplement Fabric Services With Grid Aware Services – Is This Still Middleware?  How Low Can (Should) It Go?

5. 10/1/2016 CHEP 03, California 5 Can We Draw a Line Between Fabric and Middleware?  What is the Difference Between a High Level Fabric Service and a Low Level Middleware Service?  Site Boundary? But – Many Traditional Fabric Elements Cross Site Boundaries and Many Important Middleware Components Do Not  Maybe Everything is Middleware? Even an Operating System “Translates Concrete Services to Abstract Services”  “The Fabric” Cannot be Separated From Middleware  Not a Useful Distinction

6. 10/1/2016 CHEP 03, California 6 Can We Draw a Line Between Fabric and “The Grid?”  The Fabric is Part of the Grid  Site Boundary?  Many “Pure Grid” Components Reach Inside Sites  Grid Awareness?  Grid Aware “Batch Queues” or “File Systems” May Coexist With Non-Grid Implementations  Even Operating Systems Will Be Grid Aware

7. 10/1/2016 CHEP 03, California 7 Refocus the Debate?  Focus on Standard Interfaces/Protocols Between Layers?  Good Middleware Should Provide an Abstract Service With Defined Interfaces Without Dictating Specific Lower Level Concrete Implementations  Good Middleware Should Adapt to Multiple Lower Level Protocols  Focus on Who is Responsible for What?  Site Administrators Have Specific Contractual (or Legal) Obligations  Policy Enforcement and Security are Fundamental Site Functions  Site Administrators Should Have Choices in Implementation

8. 10/1/2016 CHEP 03, California 8 Grid / Fabric Interface  Define Interfaces Sites Must Provide  Interfaces, Not Implementations  Must be Consistent with Site Policies  Grid Projects Must Help Develop Implementations  Middleware that Provides Defined Interfaces On Top of Legacy Site Implementations  When Appropriate, Reimplement Legacy Components  Develop Grid Security Model Consistent With Site Policies  Will Require Some Compromises by Sites  Must Be Flexible Enough to Accommodate Variety  Heterogeneity Must Be Expected!!!