1. Towards GLUE Schema v. 1. 2 Sergio Andreozzi – INFN/CNAF email: sergio
Towards GLUE Schema v Sergio Andreozzi – INFN/CNAF
EGEE JRA1 IT/CZ Meeting
Milano, 8 March 2005
EGEE is a project funded by the European Union under contract IST

2. OUTLINE From the RAL Meeting 25 Feb ’05
Tentative Roadmap for GLUE Schema v. 1.2 and v.2
Approved changes for V.1.2
General
Site
Service
Computing Element
Storage Element
EGEE JRA1 IT/CZ Meeting, 8 March 2005, Milan

3. GLUE face-to-face meeting
25 Feb 2005, RAL, UK
Participants:
J Schopf, Stephen Burke, Sergio Andreozzi, Steve Fisher, Matt Viljoen, Marco Mambelli, Laurence Field, Antony Wilson, Balazs Konya
Goal:
Discuss LCG/EGEE and Grid3/OSG required changes to v.1.1
Approve those changes that don’t break backwards-compatibility
EGEE JRA1 IT/CZ Meeting, 8 March 2005, Milan

4. Roadmap End of March ‘05 After the abstract description is finalized:
GLUE Schema V. 1.2
After the abstract description is finalized:
Mapping to
LDAP (Sergio) + info provider (Laurence Field)
Relational (R-GMA)
XML (Globus)
October ’05
Start discussion for major version (2.0)
Backwards compatibility is not a requirement
Inclusion of NorduGrid schema into a common design is expected
EGEE JRA1 IT/CZ Meeting, 8 March 2005, Milan

5. General Deprecated attributes: UniqueID and LocalID:
all deprecated attributes will be published until a major version is released (i.e.: in GLUE Schema v.2 they will be removed)
UniqueID and LocalID:
opacity: they are not interpreted by the user or the system as having any meaning other than as an ID
based on a DNS entry (for UniqueID, to assure global uniqueness)
no assumption that someone will try to connect to this (no relationship to a network endpoint)
Backwards-compatibility:
changes in minor release are only additive; if a new attribute replaces an old one, they will be both published
Progressive adoption:
the new features should be exploited by the matchmaking process incrementally up to not depend anymore from deprecated attributes
EGEE JRA1 IT/CZ Meeting, 8 March 2005, Milan

6. Site A Site entity is finally added
It is a management concept: Set of resources that are installed and managed by the same organization/set of persons
Each Service belongs to one and only one site!!!
EGEE JRA1 IT/CZ Meeting, 8 March 2005, Milan

7. Service A Service entity is finally added
It can be used to advertise the existence of a Grid service different than CE/SE
In version 2, all Services will be a specialization of this entity
(e.g.: for the RB specific schema, we can start from this and extend it)
EGEE JRA1 IT/CZ Meeting, 8 March 2005, Milan

8. Core Schema NEW DEPRECATED UNMODIFIED
EGEE JRA1 IT/CZ Meeting, 8 March 2005, Milan

9. Computing Element CPU vs. Job Slot concept SOLUTION:
GlueCEInfoTotalCPUs
GlueCEStateFreeCPUs
The name of the attribute is misleading as the value does not refers to a ”CPU”, but to the “possibility to run a single-processor job”
SOLUTION:
add
GlueCEPolicyAssignedJobSlots
GlueCEStateFreeJobSlots
deprecate
EGEE JRA1 IT/CZ Meeting, 8 March 2005, Milan

10. Computing Element VO view of a Computing Element Solution
Given a CE (meant as a queue in v.1.x), different policies for different groups of users cause a different perceived state of the CE
This implies a wrong perception of the amount of resources available to a group of users/VO
Solution
add a VO view of each CE with the set of attributes that can assume a different value depending on the specific user
It contains also
DefaultSE (VO-specific)
DataDir: path for transient data
ApplicationDir: path for installing VO application
EGEE JRA1 IT/CZ Meeting, 8 March 2005, Milan

11. Computing Element VO view of a Computing Element
In order to use this new information in the matchmaking process, we need a way to consider the VO-specific attributes when they are present and when a user belongs to that VO
Solution 1:
When translating from LDIF to ClassAd,
for each CE
Add as many ClassAd CE’s as many are the VO-specific views (ACL=VOName) (VO-specific CE.UID=CE.UID-VOView.LocalID)
Add one more ClassAd CE if there is at least one VO that does not have VO-specific info (ACL=list of VO’s with no specific view)
Solution 2: ???
EGEE JRA1 IT/CZ Meeting, 8 March 2005, Milan

12. Computing Element Glue.CE.VOView.DefaultSE vs. GlueCESEBind
They both express a relationship between a CE and an SE
The first is CE and VO specific
it should be used to know the default choice for writing into an SE for a user of a certain VO
The second is CE specific
to be used to resolve “input files”
to be used for getting NFS mount dir
To be better clarified how to use them. A possible starting point is:
“Write” use case: if there is a defaultSE for the User VO, then use that, otherwise resolve to what specificied in the CESEBind
For the rest use CESEBind
EGEE JRA1 IT/CZ Meeting, 8 March 2005, Milan

13. Computing Element
Glue.CE.Info.JobManager: piece of info composing the CE.UniqueID; it was missing
Glue.CE.Info.ContactString [*]:
Hostname:port/jobmanager
multi-value
Required by Grid3 as they have multiple gatekeepers and multiple job-managers in front of the same set of WN’s
Problem: how to choose among them?
EGEE JRA1 IT/CZ Meeting, 8 March 2005, Milan

14. SubCluster Added the following attributes:
PhysicalCPUs: The total number of real CPUs in the subcluster
LogicalCPUs: The effective number of CPUs in the subcluster, including the effect of hyperthreading
TmpDir: the path of a temporary directory shared across worker nodes
WNTmpDir: the path of a temporary directory local to each Worker Node
Isolate the Host-related attributes that are used for matchmaking from the whole Host model
Added the Location class:
Name, Version and Path: used by Grid3 to publish installed software
EGEE JRA1 IT/CZ Meeting, 8 March 2005, Milan

15. CE-SubCluster Discussion
Plan for supporting matchmaking in heterogeneos clusters
The upcoming GLUE Schema v.1.2 (as it is now) is not able to model CE’s that can submit to a subset of the available subclusters
Need for a specific relationship between CE and Subcluster
Do we need it in GLUE Schema v.1.2 or postpone to v.2?
Evaluate impact on MM!
EGEE JRA1 IT/CZ Meeting, 8 March 2005, Milan

16. CE/Cluster/Subcluster
NEW
DEPRECATED
UNMODIFIED
EGEE JRA1 IT/CZ Meeting, 8 March 2005, Milan

17. Storage Element
The Storage Element as a group of services, protocols and data sources
SE.SizeTotal and SE.SizeFree for high level management
Introduction of the Control Procol entity
to advertise availability of different management protocols
Capability attribute as an enumeration of strings to be used to advertise specific functionalities (e.g., space reservation)
Access Protocol and Control Protocol have the same set of attributes
Storage Area: added LocalID, Path and Type attributes
Storage Library: deprecated
EGEE JRA1 IT/CZ Meeting, 8 March 2005, Milan

18. Storage Element NEW DEPRECATED UNMODIFIED
EGEE JRA1 IT/CZ Meeting, 8 March 2005, Milan

19. Storage Library NEW DEPRECATED UNMODIFIED
EGEE JRA1 IT/CZ Meeting, 8 March 2005, Milan

20. CE-SE-Bind Deprecated AccessPoint due to wrong usage Added MountInfo:
the name of an environment variable available in each worker node assigned to the CE; the value of this variable is CE mount dir and the SE export dir
What about a “weight” attribute to expresse a preference when multiple SE are bound to a CE; the higher, the better. Default is zero. Could it be useful in MM?
NEW
DEPRECATED
UNMODIFIED
EGEE JRA1 IT/CZ Meeting, 8 March 2005, Milan

21. Host NEW DEPRECATED UNMODIFIED
EGEE JRA1 IT/CZ Meeting, 8 March 2005, Milan