The largest group meeting so far! The 20th of January we
gathered 48 people to listen to three presentations about ClearCase implementations. The
interest for ClearCase seems more intense than ever and RAIN has never had so many
visitors to a group meeting before. Three speakers were on the program:
ClearCase/MultiSite case study
|Morgan said that he would rather have a dialog with the audience instead
of a regular presentation. He started with a SHORT presentation of Ericsson Hewlett
Packard (EHPT) before describing the environment they work in. We got a good view of how
you can use MultiSite to connect different sites in a star formed network. The environment
included 3 sites running ClearCase on HP-UX with 30 developers. They tried to set up a
MultiSite link to the Hewlett Packard site in India, but the firewalls at Ericsson put an
end to those plans.
Initially they tried to design a common ClearCase environment, but
the design work differs too much to make that possible. The part that Morgan works in
migrated from RCS to ClearCase about 1 year ago. The introduction was not without
problems. It took about 8 months to get the environment they wanted implemented in all
projects. Other problems at EHPT has been how to handle 3rd party products. Now, some of
them are handled in ClearCase, others are handled by the IS/IT department.
The support responsibility is often a big issue when introducing ClearCase. Who should
be responsible for what? At EHPT, the IS/IT department does the ClearCase administration.
Each project then has an appointed CM that handles the VOB administration in the project
and act as an interface to the IS/IT department. Morgan estimated the time for supporting
developers in ClearCase related issues to about 8 hours per week.
Morgan wants to improve the environment by adding routines for handling documents in
ClearCase, add one site to the MultiSite network, adding build support for different
platforms and to spread out the CM competence to more people in the organisation.
|Lennart Larsson is a true ClearCase guru with hands on experiences since
1994. He works as the application support responsible for Ericsson Microwave (EMW) in
Mölndal. Lennart has an interesting presentation technique with a lot of hand moving
involved. He is very intense and engaged in his work and it is obvious that he is proud of
what he is doing. With all rights of course.
With large products, parallel development
and long product life cycles, release handling and version tree handling is not an easy
task, but Lennart has really been digging deep into this subject. To be able to handle
these large version trees, EMW is using a function in ClearCase called "Obsolete
branches" to get rid of branches that are not used/valid any more. Development takes
place on a development branch and is then merged into the valid maintenance branch. Take a
close look at Lennarts slides to get a graphical view of how it works.
When working with MultiSite, branching must be handled slightly different. The reason
is that you can only work in a branch that is created at your own site. This means that
only one site has access to the main branch. So to make all sites work in the same way,
the main branch should be used very rarely. EMW is also working with incremental
development processes. To give each increment its own branch is not a revolutionary idea,
but to make the method of obsolete branches work, all increment branches should origin
from the main branch (again, take a look at Lennarts slides).
Lennarts main advises for branching in ClearCase are:
- Create a branching strategy
- Consider R-state (release versions) handling
- Consider the release philosophy
- Create templates for configuration specifications
- Use obsolete branches
Common usage model
|Subtitle of Ulfs presentation was "Using ClearCase and a change
process". Common usage model is a set of routines and role descriptions to use in a
ClearCase environment. The model suits well with the new version of RUP (former know as
ROP) and has shown to useful for small and mid sized organisations that lacks of
formalised routines around configuration management.
I know I was not the only one
smiling when Ulf said that "RUP is a CM standard next to IEEE and SEI... Well, soon
it is". We were also reminded that CM is a rather new discipline when Ulf asked
"How many of you have been working as configuration managers................ for 7
years or more?". The need for routines should not be underestimated, especially when
introducing a new tool like ClearCase. Check out Ulfs presentation as well to get more
information about the Common usage model.
With this big interest for ClearCase and configuration management, I hope we can
arrange a new group meeting with a similar theme again soon. CU then!