Monday July 26, 2010
Martin Skou Andersen
Discussions and agreements on WHO, WHY, WHEN, HOW.
The definition of the standard interface for the EMI execution service
is one of the most important priority of the project
Therefore the relevant people should be committed at least for 50% of
their time in the definition of such EMI ES specification
The main relevant persons part of this process for the definition
of the specification are:
ARC: Aleksandr, Balazs (not full time, not for all technical
gLite: Luigi, Massimo
UNICORE: Bernd, Shahbaz (Christoph can't participate in such
Since LB people are planning to use the EMI specification, we will
need to show them the specification, so they will need to be
involved at some time to check what (not needed now)
The delegation part of the specification must be also submitted
to the security people.
We need a common interface for describing, submitting and managing
jobs. We need therefore to produce a high level techninal document
with such specification, from where it must be possible to start
WHEN The specification must be ready by October (there is a milestone)
But the work should be finalized even before (e.g. it would be good to
present it at OGF that will take place in Brussels at the end of
Luigi notes that the XML rendering for Glue2 specification is a
prerequisite. Balasz reports that it will be finalized by September
HOW Besides these activities within EMI, there are also the activities
within the OGF-PGI WG, which should go in parallel.
The idea is to be able to push our EMI specification to the
OGF-PGI WG when ready.
After this Padova F2F meeting, it is agreed that EMI ES specification
activities will continue in phoneconferences (2 per weeks), to be held
on Mondays and Thursdays (from 09.30 to 11.30) starting from September.
The Lund phone conf. system (accessible via skype) will be used.
This EMI ES specification activities should be considered as part
of the JRA1 standardization task.
The email@example.com mailing list will be used
The document (also the draft versions) and all the other
relevant stuff (meeting notes, etc.) will be made available in
the EMI wiki (under the JRA1 standardization task area:
It is agreed to always use the "EMI Execution Service (ES)"
terminology (e.g. let us not use "AGU" anymore)
It is necessary to identify a person responsible for leading the process
(calling meetings, etc.) and being the editor of the document.
Bernd will be asked if he can take such responsability
Discussion about the scope of our specification activities.
It is agreed that the specification should be relevant for computing elements,
while higher level job management services (e.g. the gLite WMS) are out of
The following items are in-scope and should therefore be tackled by the
specification that we have to define:
- Interface to manage jobs
- job info (status, detailed info, query)
- Resource information (query)
- Delegation (to satisfy data staging)
- State model
- Data staging
- Job description (“EMI-JSDL”)
The architecture presented in v0.4 of the document referred to a monolithic
setup with 3 port-types all provided by the same service:
- Execution (Create, Change, Cancel, Wipe, GetActivityStatus,
- Info (QueryResource, QueryActivity),
It is agreed to have instead a new modular setup, with 2 "modules":
Activity-Factory is used to create jobs and manage resource (CE) information
- Create port: CreateActivity
- ResourceInfo port: QueryResourceInfo
- Delegation port
Activity-Manager used to manage jobs and get job info
- ActivityManagement port: Change, Cancel, Wipe, GetActivityStatus by ID,
GetActivityInfo by ID
- ActivityInfo port: QueryActivityInfo, GetActivityStatus by ID,
GetActivityInfo by ID
- Delegation port
QueryResourceInfo must report only CE information. It must not report at all
about jobs, not even the list of job IDs: the Factory doesn't know anything
about the list of active jobs.
QueryResourceInfo must also report about the end point(s) of the "associated"
It must be further discussed if GetActivityStatus and GetActivityInfo must
be part of both ActivityManagement and ActivityInfo ports
Discussions about the data staging. The text circulated via mail by
Aleksandr some weeks ago are used as input in the discussion.
Agreed on the concepts of stage-in, session and stage-out directories
Agreed on the possible stage-in/stage-out models
All the outcomes and agreements of such discussions are presented in the
"Data staging functionality" section (1.2) of the document v.0.7.
Still to be decided if and how collections of files should be supported
The discussion about “protocol-specific extra variables” will be
done when discussing the EMI-JSDL
Tuesday July 27, 2010
Paolo Andreetto (just for the discussions related to delegation)
Martin Skou Andersen
It is agreed that scope is only x509 token delegation.
SAML token is reserved for future versions of the specification
It is agreed that only 3820 proxies are allowed. Any extension is allowed.
It is agreed that there are two possible scenarios for x509 delegation.
- X509 tokens can come both directly from the client and transferred to the ES.
This is a scenario that must be supported
- x509 tokens can be fetched from a credential service (such as myproxy, SLCS).
This is a scenario whose implementation is optional
The type of supported credential services must be published as part of
resource description (ES capability)
See "Delegation" section (1.3) of the document v. 0.7 for more details
on the outcomes of the discussions.
Defined the details of the Delegation Port-Type to support the first scenario
(see section 7 "Interface: Delegation Port-Type" of the document v. 0.7)
Still to be decided about the association of credentials to data staging
elements (to be discussed when discussing the EMI-JSDL).
Aleksandr's proposes to allow specifying a delegationid per file, per staging
element, per job.
Activity State model
Discussions and agreement on state model
State model consists of main states and secondary states. A job can only be
in one main state but can have multiple secondary states.
Outcomes (i.e. states that have been defined) in "State definitions"
section (8.1) of the document v. 0.7.
To be decided when discussing the wipe operation about the purged state.
Discussions and agreeement on the possible state model transitions
Outcomes in "State transitions" section (8.2) of the document v. 0.7 and in
what was written in the whiteboard (pictures taken by Aleksandr to be
reported in section 8.2)
The implementations of the "failure recovery transitions" are optional
(i.e. some services can be able to support some recoveries)
Wednesday July 28, 2010
Martin Skou Andersen
Thorough discussion of the CreateActivity operation
Outcomes reported in section "CreateActivity operation" 2.1 of the document
Superficial discussions of all the other operations (outcomes of such discussions
reported in the document v. 0.7)
Some items still to be discussed:
- why a cancel operation is needed (why the changeactivity can't be used
- do we need to provide operations to suspend and then resume jobs in the lrms ?
Version 0.7 of the document produced and uploaded in the wiki
Text marked in yellows refer to items which need to be (further) discussed
or need to be rephrased to make them consistent with the rest of the document.
Sections whose name is marked in yellow haven't been discussed.
- By next wed (Aug 4) Massimo will produce a v. 0.8 document doing the needed
cleaning, make the whole document consistent and readable also for
people not attending the meeting
It will have to include also the white board snapshots (to be sent to Massimo
by friday), in particular the following ones:
- architecture (Shabbaz)
- data staging figure (Alek)
- 3 directories (Alek)
- delegation figure (Alek)
- state transition figure (Alek)
- Luigi and Balazs will provide (by friday) the drafts/scheletons of the
wsdl and jsdl schemas (to be included in the appendix of the document)
- Discuss in the sept's phoneconfs the remaining set of operations
including the HOLD/RESUME problem area
- Find a person responsible to drive the process and to be the editor of the
document (to be confirmed if this role can be taken by Bernd)
- The first phoneconf (scheduled for September 2) will be planned by such
person (or by Balazs if some person is not appointed before)
- schedule a F2F meeting (two full days and a third half day) in / near
Date: Tuesday 21 September - Thursday 23 September (possible to shift one
day and start on 22 and finish on 24)
To be finalized by the end of the week (Balazs will drive the process)
There are minutes attached to this event.