UK Globus Week

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Legacy code deployment and execution in GT3/GT4
Grids experiences with migrating GEMLCA from GT3
to GT4
Grid Execution Management for Legacy Code
Architecture
Thierry Delaitre Cavendish School of Computer
Science University of Westminster T.Delaitre_at_wmin.
ac.uk
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UK E-science OGSA Testbed

• test and evaluate OGSA/GT3 core
• evaluate performance, ease of deployment and use,
  and interoperability

University of Portsmouth University of
Westminster University of Manchester University
of Reading Daresbury, CCLRC University of
Southampton SZTAKI (Hungary)
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The development team

• Univ. of Westminster MTA SZTAKI
• Prof. Peter Kacsuk 1. Prof. Peter Kacsuk
• Prof. Stephen Winter 2. Zoltan Farkas
• Dr. Thierry Delaitre 3. Csaba Nemeth
• Dr. Gabor Terstyanszky 4. Tamas Boczko
• Ariel Goyeneche 5. Jozsef Patvarczki
• Tamas Kiss 6. Gabor Hermann
• Noam Weingarten 7. Gergely Sipos
• Gabor Kecskemeti
• Yonathan Zetuny
• Szabolcs Illes
• Peter Bulyaki

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Presentation Outline

1. GEMLCA objectives
2. Concept of GEMLCA
3. Experiences with migrating GEMLCA
4. GEMLCA client, the P-GRADE portal DEMO
5. Conclusion future work

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Legacy Applications

• Code from the past, maintained because it works
• Often supports business critical functions
• Not Grid enabled

What to do with legacy codes when utilising the
Grid?

• Bin them and implement Grid enabled applications

• Reengineer them

• Port them onto the Grid with minimal user effort

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GEMLCA Grid Execution Management for Legacy
Code Architecture
Objectives

• To deploy legacy code applications as Grid
  services without reengineering the original code
  and minimal user effort
• To create complex Grid workflows where components
  are legacy code applications
• To make these functions available from a Grid
  Portal

GEMLCA
GEMLCA P-GRADE Portal Integration
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Legacy applications in service-oriented
GridsGemlca PGrade portal approach thin client
P-GRADE Portal Server
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Presentation Outline

1. GEMLCA objectives
2. Concept of GEMLCA
3. Experiences with migrating GEMLCA
4. GEMLCA client, the P-GRADE portal DEMO
5. Conclusion future work

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GEMLCA Concept
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GEMLCA lifecycle Job submission
Client sign-on
List of LCGSs
LCGS Interfaces
Job Process
Job Process
..
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GEMLCA lifecycle Get results
Client sign-on
List of LCGSs
LCGS Interfaces
LCGS status Result
Kill LCGS
Job Process
Job Process
..
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GEMLCA lifecycle Deployments
Client sign-on
List of LCGSs
LCGS Interfaces
LCGS status Result
Kill LCGS
Client sign-on
Legacy Code Deployment
Job Process
Job Process
..
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Presentation Outline

1. GEMLCA objectives
2. Concept of GEMLCA
3. Experiences with migrating GEMLCA
4. GEMLCA client, the P-GRADE portal DEMO
5. Conclusion future work

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Migrating GEMLCA from GT3 to GT4What needs to
be done ?

• GEMLCA package for GT3 released on November 2004
• Convert existing List, Process and Admin WS from
  OGSI to WSRF

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Experiences with migrating GEMLCA from GT3 to GT4
Advantages of GT4 over GT3 for GEMLCA

• Better MMJFS performance, no UHE
• Better performance when sending/receiving XML
  messages
• GT4 documentation is better than in GT3 and
  continues to improve

How easy was it to convert from OGSI to WSRF ?

• Straightforward to convert OGSI to WSRF class
  style

What were the difficulties from GT3 to GT4 ?

• WSDL and complex types (3 slides)
• Security (1 slide)
• Gram API (1 slide)

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Experiences with migrating GEMLCA from GT3 to
GT4WSDL Interfaces

• Native Axis java2wsdl not suitable for converting
  Java interfaces to GT4 WSDL unless decorating is
  modified. WSDL for List and Process WS done
  manually. WSDL for Admin WS generated
  automatically from Java Interface once we added
  an XSLT processing step after java2WSDL.
• For the List and Process WS, we had to guess the
  expected WSDL using a trial and error process.
  Original WSDL was inspired from Borjas tutorial
  (at the time of 3.9.3) and from the GWSDL.
• We spent lots of time figuring out how to use
  complex types such as passing multiple parameters
  or returning String . Solution is to use an
  Object (i.e. Beans). Objects also need to be used
  in 3.9.5 when returning String (was ok with
  3.9.4)

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Experiences with migrating GEMLCA from GT3 to
GT4GLCListgetGLCList WS and complex typesWSDL
generated manually for List WS

• ltxsdelement namegetGLCListResponsegt
• ltxsdcomplexTypegt
• ltxsdsequencegt
• ltxsdelement namelegacyCodes
  typexsdstring minOccurs0
  maxOccursunbounded/gt
• lt/xsdsequencegt
• lt/xsdcomplexTypegt
• lt/xsdelementgt

import uk.ac.wmin.cpc.gemlca.frontend.stubs.GLCLis
t.GetGLCListRequest import uk.ac.wmin.cpc.gemlca.
frontend.stubs.GLCList.GetGLCListResponse public
class GLCList implements GLCListNamespaces
public GetGLCListResponse getGLCList(GetGLCList
Request parameters)
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Experiences with migrating GEMLCA from GT3 to
GT4GLCAdmingetPopulatedDtd WS and complex
typesWSDL generated automatically for Admin WS

• public interface GLCAdmin
• public String getPopulatedDtd(String LCName,
  boolean pUserLegacyCodes)
• public boolean writeConfig(String
  EnvironmentDescription, boolean
  pUserLegacyCodes)

import uk.ac.wmin.cpc.gemlca.frontend.stubs.GLCAdm
in.GetPopulatedDtd import uk.ac.wmin.cpc.gemlca.f
rontend.stubs.GLCAdmin.GetPopulatedDtdResponse p
ublic class GLCAdmin implements
GLCAdminNamespaces public GetPopulatedDtdRespon
se getPopulatedDtd(GetPopulatedDtd Params)
String LCName Params.getIn0() boolean
pUserLegacyCode Params.isIn1()
ltelement namegetPopulatedDtdgt ltcomplexTypegt
ltsequencegt ltelement namein0
typexsdstring/gt ltelement namein1
typexsdboolean/gt lt/sequencegt
lt/complexTypegt lt/elementgt
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Experiences with migrating GEMLCA from GT3 to
GT4Security

• Cannot do proxy delegation when client
  authorisation is set to none. We experienced the
  GT3.2.0 to GT3.2.1 security enhancement !
• host/self auth not suitable
• Using identity of service solution
• Proxy delegation working first-time only after
  container start-up
• There is a single instance of the stateless Web
  Service and hence we cannot use
• SecurityManager.getManager().setServiceOwnerFromC
  ontext()

Iterator itorg.globus.gsi.jaas.JassSubject.getCur
rentSubject().getPrivateCredential().iterator() I
f(it.hasNext()) proxy (GSSCredential)
it.next() job new GramJob Job.setCredential(p
roxy)
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Experiences with migrating GEMLCA from GT3 to
GT4GRAM API

• Tried to use low-level Gram API but we
  experienced some bugs in the documentation which
  we fedback. Job status refresh was not working at
  the beginning.
• Ended up using GramJob API as in GT3.
• Still cannot use notification call-backs when
  GramJob API is embedded into a WS. (Currently
  using polling)

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What wed like to see done in GT4

• Proper detailed documentation (has improved but
  needs to continue)
• GRAM call-back notification in a WS
• Get Condor job manager working with Globus
• Condor was not working properly for us in GT3
  possibly due to NFS race conditions (same
  reported by James Frey for PBS/LSF). Is it the
  same in GT4 ? What is the recommended deployment
  scenario ? Can condor master and GT node
  installed on different machines ? Is the condors
  SEG code reliable in GT4 ?
• PBS
• PBS not working even though it should work
  (PBS.pm uses SEG)
• Decouple PBS master node and Globus Grid node on
  different machines (pbs tracejob ?).
• Compilation issues on SLES9 AMD 64bits Opteron
• Tried using CVS but fait_accomplit fails
• GT4 client not working on 64 bits OS using 32 or
  64 bits JVM
• Exception in thread "main" java.lang.NoSuchMethodE
  rror org.apache.axis.description.TypeDesc.ltinitgt(
  Ljava/lang/ClassZ)V
• at org.apache.axis.message.addressing.EndpointRefe
  renceType.ltclinitgt(EndpointReferenceType.java333)

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Presentation Outline

1. GEMLCA objectives
2. Concept of GEMLCA
3. Server side
4. GEMLCA client the P-GRADE portal Live DEMO
5. Conclusion future work

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P-GRADE Grid PortalPG-Portal functionalities
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Conclusions

• GEMLCA enables the deployment of legacy code
  applications as Grid services with minimal user
  effort.
• GEMLCA is integrated with the P-GRADE portal to
  offer user-friendly development and execution
  environment.
• The integrated GEMLCA P-GRADE solution was
  successfully demonstrated using the traffic
  simulator and other applications
• Gemlca package for GT3 released last November
• Gemlca package for GT4 to be released in May 2005

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Thank you for your attention
Email gemlca-discuss_at_cpc.wmin.ac.uk Websites ww
w.cpc.wmin.ac.uk/gemlca www.lpds.sztaki.hu/pgporta
l