Planning Process for SC4
First version 25jan06 by Ian Bird, Erwin Laure and Les Robertson after
discussions in the LCG MB on 10, 17 and 24 January.
version 31jan06 by Les Robertson, reflecting comments received from the
MB members - modifications in blue.
purpose of the TCG is to agree on the priorities for the development teams
within EGEE, taking account of the requirements and priorities of the
different application communities, and the resources available to the
developers. There are also various other constraints that need to be taken
into account, such as the resources available for testing and
deployment, the priority that developers have to give to maintenance of
functionality already in production, and externally imposed timetables like
the timing of the service phasing of LCG. In general the TCG will be looking
at the medium term - planning for developments that could be made available
in a distribution 6-9 months ahead (therefore released to deployment for
testing 4-6 months ahead).
The current LHC
machine schedule has led to the LCG MB deciding that SC4 must start at the
latest on 1 June 06. This in turn leads to the following constraints on the
delivery of the middleware:.
- end April -
distribution fully tested and available to sites
- 15 March -
final version of components available (following integration and basic
certification) on the pre-production service for user testing (Beta test)
implies that very little other than the software already delivered to
deployment will make it into the release for SC4 - in other words there
is very limited scope for TCG decisions that will influence what is
available in SC4.
Planning for SC4
In LCG we
agreed that the deployment plan for SC4 will be fixed in advance on the
basis of realistic assessments of software availability and of the time and
resources required to fully test and deploy the components.
This approach gives priority to availability and reliability over new
functionality, but avoids the expectation gap that developed during 2005.
This approach was strongly recommended by the experiment spokesmen in the OB
and was presented in the meeting with the spokesmen on 13 January.
management team is responsible for preparing the plan for SC4. Flavia is
drafting the plan, taking account of what can be delivered and supported by
the developers (EGEE and others), integrated and tested by deployment,
thoroughly tested by the experiments, and deployed by the sites - all within
the time constraints of SC4. Realistically,
as far as EGEE middleware is concerned, this plan can only
include functionality already in the LCG2.7 distribution or in the gLite 1.5
code already in the hands of the deployment people. If we are to keep to the
dates defined above there is no scope for adding additional functions,
rather we must understand whether all of this functionality
can realistically be deployed.
If we are to achieve an SC4 start date of 1
June we have to work to a very tight timetable. The target for the planning
phase is to arrive at an agreement on the
plan by the end of the Mumbai Service Challenge Workshop, to be documented
during the following week and submitted for approval by the GDB (email). It
should then be possible to agree the plan formally in the MB before the end
Much of the new
functionality discussed in the Baseline Services Working Group at the end of
last year will not be ready for SC4. We must therefore begin to plan for
another functionality release of the distribution in October 2006
(corresponding to the opening of the initial LHC
service - assuming the the service must be fully commissioned by 1 April
2007). This places a constraint on the TCG middleware development
planning, to deliver to deployment by the end of June.
The SRM 2.1
implementations are being delivered for testing during the first quarter of
2006. The SRM working group (run by Maarten Litmaath) must develop a testing
and deployment plan that will run in parallel to SC4. This has to test
compatibility between the implementation, support by the common clients
(e.g. FTS, GFAL, lcg-utils), and testing by the experiments. The dates for
introduction of SRM 2.1 will not be able to be decided until we are some way
into the test programme.
New and novel
functionality, such as GPBOX, may have to go through an evaluation process
between developers and users before its final form is agreed. Such
evaluations should be planned by the TCG in collaboration with one or more
of the experiments. LCG would not be involved in a
planning role so far in advance of availability.