# Presentation: 434817

## Grids: The Top Ten Questions

- Jennifer M. Schopf
- UK National eScience Centre
- Argonne National Lab
- January 14, 2005

## Ten Things WeHate About The Grid

- Jennifer M. Schopf
- UK National eScience Centre
- Argonne National Lab
- (With significant input from
- Bill Nitzberg, PBS)
- January 14, 2005

## What Is a Grid?

- Shared resources
- Computers, storage, sensors, networks, ...
- Sharing always conditional: issues of trust, policy, negotiation, payment, ...
- Coordinated problem solving
- Beyond client-server: distributed data analysis, computation, collaboration, ...
- Multiple sites (multiple administrative domains)
- Dynamic, multi-institutional virtual orgs
- Community overlays on classic org structures
- Large or small, static or dynamic

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Not A New Idea

- Late 70’s – Networked operating systems
- Late 80’s – Distributed operating system
- Early 90’s – Heterogeneous computing
- Mid 90’s - Metacomputing
- Then the “Grid” – Foster and Keselman, 1999

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Relation to Other Approaches

- Distributed computing
- Generally a client-server model
- Parallel computing
- Limited to one machine/site
- Peer-to-peer technologies
- Limited scope and mechanisms
- Enterprise-level distributed computing
- Limited cross-organizational support

- 10 Open Issues in Grid Computing, Jennifer Schopf

## How are Grids Different?

- Autonomy
- Heterogeneity
- Resources are more the CPU and networks
- Focus on the user
- These differences create many of the problems addressed in this talk but also make the system much more usable than its predecessors

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Who uses Grids?

- A biochemist exploits 10,000 computers to screen 100,000 compounds in an hour
- 1,000 physicists worldwide pool resources for petaop analyses of petabytes of data
- Civil engineers collaborate to design, execute, & analyze shake table experiments
- Climate scientists visualize, annotate, & analyze terabyte simulation datasets
- An emergency response team couples real time data, weather model, population data

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Who uses Grids? (contd)

- A multidisciplinary analysis in aerospace couples code and data in four companies
- A home user invokes architectural design functions at an application service provider
- An application service provider purchases cycles from compute cycle providers
- Scientists working for a multinational soap company design a new product
- A community group pools members’ PCs to analyze alternative designs for a local road

- 10 Open Issues in Grid Computing, Jennifer Schopf

## What’s the problem?

- Computational Grids are becoming more and more common
- Collaborations are being developed
- Governments are giving lots of money
- Globus seems to be _everywhere_
- Happy application scientists are few and far between

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Things heard recently...

- “Isn’t the Grid just a funding construct?”
- “No one can really define it, everyone wants an app that can do it, and companies that claim to do it are getting a lot of interest.” – SlashDot, March 2003
- "Grid computing has been more hype than reality,“ - Hewlett-Packard CEO Carly Fiorina, Fall 2003
- “We tried to install Globus and found out that it was too hard to do.  So we decided to just write our own....”

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Grid2096

- 10 Open Issues in Grid Computing, Jennifer Schopf

## This Talk- FIX

- Intro Bits (done that)
- Open issues in Grid computing
- Users
- Information
- Security
- Performance
- Socio-Political
- Structure:
- Question, Discussion, Moral (def. a lesson or principle contained in or taught by a fable, a story, or an event)

- 10 Open Issues in Grid Computing, Jennifer Schopf

## A grain of salt

- Many of the problems I’ll discuss are in the process of being addressed by various groups
- There may be on-going work or solutions that I don’t know about, I’ll apologize now
- These are my opinions, not those of Argonne National Lab, the Globus Alliance, NeSC, EPCC,  etc...

- 10 Open Issues in Grid Computing, Jennifer Schopf

## 1. Why aren’t there (happy) users?

- FACT: Many users have been told to use the Grid to get funding, not because they actually want to
- FACT: There are a few well known successes (LHC, CACTUS, and a couple others) but some people think these are one-offs
- FACT: In July I spoke with 25 UK user groups, and on occasion it got ugly
- _[www.nesc.ac.uk/technical_papers/UKeS-2004-08.](http://www.nesc.ac.uk/technical_papers/UKeS-2004-08.pdf)__[pdf](http://www.nesc.ac.uk/technical_papers/UKeS-2004-08.pdf)_

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Move from sequential to parallel computing

- Parallel computing showed us that they “If you build it they will come” scenario just won’t work
- Until debuggers, fast compilers, languages, libraries, etc. the users didn’t want to use parallel machines
- Many hundreds, even thousand, of hours went into re-writing codes for parallel machines

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Heroic Effort Required for the Grid

- There is the impression (right or wrong) that only heroic efforts will allow you to use a Grid
- Some re-writing of code required
- Access to resources isn’t easy even once code is changed

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Where are the user level tools?

- What a user would like:
- “Run my job, finish by lunch”
- “Get a data set that has these attributes”
- “Tell me when that simulation will finish”
- Where are we today:
- Specify exact machines, data files, explicit data transfers, etc
- Little (or no) dynamic information or prediction

- 10 Open Issues in Grid Computing, Jennifer Schopf

## The “Ideal” Grid (F&K, 1999)

- Pervasive
- Dependable
- Consistent
- Inexpensive

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Today

- Pervasive
- Special case testbeds in most instances
- Dependable
- Resources up and down
- Consistent
- Standards still developing
- Inexpensive
- Not yet!
- So can we get there?

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Why aren’t there end-to-end solutions yet?

- Globus Toolkit is to a Grid Application
- Like
- Apache is to an eCommerce Website
- Glue is needed to make it real

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Moral: How do we move forward?

- Users will only come when they have decent tools
- simple enough for “easy” use
- robust enough for “stupid” use
- still allow work arounds for “hard-core” use
- We (arguably) now have basic functionality, but we don’t know the (real) use cases yet

- 10 Open Issues in Grid Computing, Jennifer Schopf

## 2. Why don’t we have usage scenarios?

- Software often doesn’t do what a user wants
- One example- original replica catalogue from Globus, logical name to physical file name mapping
- The way the developer envisioned the software being used was/is very different from how the user wants to use it
- Many tools are used “off label”

- 10 Open Issues in Grid Computing, Jennifer Schopf

## “Off Label” Use

- Tool built to do A is used for B
- This is good since a user has something to use
- This is bad since the tool is being in a way that wasn’t envisaged
- Arch concerns
- Scaling concerns
- Etc
- But without use of the tool, there’s no way to know how it will be used!

- 10 Open Issues in Grid Computing, Jennifer Schopf

## What is a usage scenario?

- Information from the user about a specific use case
- What’s the right level of detail?
- What’s a “general” use case?
- Note: much application built software is one-off, but we need general tools that can adapt
- Who does this?
- Application scientists and computer scientists speak different languages (eg. C. Pancake)

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Moral:

- Without better _communication_ between developers and users, the Grid cannot succeed
- Grid is about people, not just machines

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Information

- The Grid **IS** information
- How do we find out about it?
- How do we understand what it is?

- 10 Open Issues in Grid Computing, Jennifer Schopf

## 3. Where do we get information from?

- Open question – how should I store the information about a Grid?
- Globus Monitoring and Discovery Service (MDS)
- A tool that does streaming data like R-GMA?
- A cluster tool over many sites like Ganglia?
- A certification tool like Inca from the TG project?
- A Grid-wide data base?
- All of these are right for some of the data, no one is right for all uses

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Why are so many tools bad?

- Large number of tools isn’t bad
- Large number of tools that have no way to interoperate is!

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Need for Standard Interfaces

- Need for standard APIs and protocols to allow easier
- Access to data sources
- Registration of data
- Archiving tools
- Standards for what information is available
- Standards for communication of errors
- This is in part what inspired the move to GT3!

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Moral:

- We have 100’s of monitoring systems but no real monitoring going on for many projects
- Without information about the Grid, it will not be usable

- 10 Open Issues in Grid Computing, Jennifer Schopf

## 4. How do we understand information once we get it?

- Assume we have access to information about the Grid – can we use it?
- A monitoring system says “the load on machine X is Y”
- A scheduler wants to evaluate this data
- No common language for this to be communicated
- Some effort now to come up with a common schema (GLUE schema, work with CIM in GGF) but this only touched the surface, no agreement for moving forward

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Moral:

- Without some kind of standards or agreements, all the information in the world won’t do us any good

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Overview-FIX

- What is a Grid
- Information
- Security
- Performance
- Socio-Political
- Other issues

- 10 Open Issues in Grid Computing, Jennifer Schopf

## 5. How do we make Grids secure?

- Without security we can’t have a Grid
- EVERYTHING needs to be secure-
- Who can run on a machine
- File transfers
- What data does someone have access to	 (program data, system data)
- Who can access which services?

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Security vs. Usability

- Users want security but don’t want to deal with it
- If security is hard- it won’t be used
- Most security (including Grid Security Infrastructure (GSI)) is based on public key infrastructure (PKI)
- Users have files (public and private keys) that must be secure, use reasonable passwords, etc.

- 10 Open Issues in Grid Computing, Jennifer Schopf

## What about...

- Multiple certificates?
- Group access?
- Dynamic policy changes?
- Scalability?
- Overheads
- Etc., etc., etc...

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Moral:

- Until security is made easier to use, it won’t be used
- Until security is made easier to manage at the group level, it won’t be used
- Without security no one will really use the Grid

- 10 Open Issues in Grid Computing, Jennifer Schopf

## 6. What about performance?

- It’s not enough to use the Grid, it has to perform – otherwise, why bother?
- First prototypes rarely consider perf.
- MDS1–centralized LDAP
- MDS2–decentralized LDAP
- MDS3–decentralized Grid service
- MDS4-decentralized Web service
- Often performance is simply not known

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Performance of GIS Information Servers vs. Number of Users

- Zhang, Freschl, and Schopf, A Performance Study of Monitoring and Information Services for Distributed Systems, submitted to HPDC 2003.

- 10 Open Issues in Grid Computing, Jennifer Schopf

## What we found

- Performance can be a matter of deployment
- Effect of background load
- Effect of network bandwidth
- Performance can be affected by underlying infrastructure
- LDAP/JAVA strengths and weaknesses
- Performance can be improved using standard CS techniques
- Caching; multi-threading; etc.

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Moral:

- Performance should be analyzed early and often
- Prototypes should be recognized as such and thrown out
- Without performance, no reason to use a Grid

- 10 Open Issues in Grid Computing, Jennifer Schopf

## 7. What do we do about variance?

- Resources on the Grid change with time
- Bandwidth
- CPU load
- Disk space
- Memory usage
- Queue sizes

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Variance – technical problem

- How do you tell if something is slow versus broken?
- How do you make a prediction?

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Variance – socio-political

- Users want the same application to take roughly the same amount of time every time you run it
- Our experience – a longer running time that’s more predictable is preferred to a high variance, high risk situation

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Moral:

- Variance is here to live with, we need techniques to take advantage of it

- 10 Open Issues in Grid Computing, Jennifer Schopf

## 8. How do we set up a Grid testbed?

- Bill Johnson, LBNL, talks about this often, based on IPG experience
- Get the sys admins involved
- Have a standard set-up
- Make this a priority at the start of a project
- Accounting – open issue
- Cross-site scheduling – open issue

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Example: Installing Globus

- Problem with GT2- how do you know it’s ok?
- Now have test scripts
- _[http://www-unix.globus.org/toolkit/testing/](http://www-unix.globus.org/toolkit/testing/)_
- But it would be better to have somethig automatic

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Moral:

- Users are building testbeds, but this is still hard
- Need to have rule of thumb published for assistance with this

- 10 Open Issues in Grid Computing, Jennifer Schopf

## 9. Socio-political Issues

- Hardest problems are often not technical ones
- Multiple administration domains means multiple policies
- Multiple countries means multiple communication styles
- Decisions are often made on non-technical basis

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Communication is hard

- Too many people in the mix
- Not everyone is informed of status updates
- Often hallway conversation becomes what people believe
- Too often assumptions are not verified
- Many communication styles can lead to misunderstandings

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Moral:

- Ongoing efforts to continue better communication are needed to build a global community
- When in doubt – ask someone of directly!

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Overview-FIX

- What is a Grid
- Information
- Security
- Performance
- Socio-Political
- Other issues

- 10 Open Issues in Grid Computing, Jennifer Schopf

## 10+: Other open problems

- Where are the benefits to encourage sharing on the Grid?
- Where are the benefits for the sys admins – users get a plus, PIs get a plus but what about them?
- How do we educate the funding agencies about the need for hardened software, documentation, and support?
- What cost models are needed by the Grid?
- Economic Grids are only the first step

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Progress

- Significant improvements in security infrastructure
- Basic functionality is much closer
- More funding aid for support
- Need for better-defined use cases and simpler deployment has been strengthened, as has the need for basic information and basic information services
- Over 100K downloads of Globus Toolkit v3

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Where are theperformance metrics for success?

- No more “Grid” papers, just a footnote that states “This work was achieved using the Grid”
- Supercomputer centers don’t give a user the choice of using their machines or the Grid, that line doesn’t exist
- SuperComputing demos can be run at any time of the year

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Conclusion

- Many interesting problems are left – both in terms of research and deployment issues
- Much work is being done to help address these open issues
- Next year’s open issues will be very different

- 10 Open Issues in Grid Computing, Jennifer Schopf

## References

- This talk:
- _[www.mcs.anl.gov/~jms/Talks](http://www.mcs.anl.gov/~jms/Talks)_ (not there yet)
- Journal paper version of this talk (dated):
- _[www.mcs.anl.gov/Pubs/jmspubs.html](http://www.mcs.anl.gov/Pubs/jmspubs.html)_
- Globus:
- _[www.globus.org](http://www.globus.org/)_
- GGF:
- _[www.ggf.org](http://www.ggf.org/)_
- Conversations with 25 UK User groups
- _[http://www.nesc.ac.uk/technical_papers/UKeS-2004-08.](http://www.nesc.ac.uk/technical_papers/UKeS-2004-08.pdf)__[pdf](http://www.nesc.ac.uk/technical_papers/UKeS-2004-08.pdf)_

- 10 Open Issues in Grid Computing, Jennifer Schopf

## Contact Information

- Jennifer M. Schopf
- jms@mcs.anl.gov
- _[www.mcs.anl.gov/~jms](http://www.mcs.anl.gov/~jms)_
- Support from DOE, NASA, NSF, IBM, Microsoft

- 10 Open Issues in Grid Computing, Jennifer Schopf