Rational Rose Clear Case Experience/Stories Needed

Justin Mason jm@jmason.org
Tue, 06 Nov 2001 23:35:57 +1100

> Does anyone have any solid ClearCase horror stories they can relate to me?

I've experienced plenty of ClearCase horrors.  Now, last time I used it
was over 3 years ago, mind, but:

  - it's very expensive, with per-developer network licensing.  And if you
    want to collaborate over a WAN or the 'net, MultiSite'll really bleed
    you dry.

  - it couldn't work offline, without MultiSite.  You always needed a fast
    LAN connection to the Clearcase server(s) -- and, obviously, the
    servers needed to be up.  (I think they have "snapshot views" now
    though, which mitigate this.)

  - the load it imposed was gigantic; hence, massively increased hardware
    costs.  Also, since every single read of a checked-in file needs an
    NFS read, you want to have a really fast network.

  - MVFS (the multi-version filesystem) is just that -- a versioning fs
    kernel module, which then talked to userlevel servers and NFS.  If
    it's buggy, and it frequently was!, you get kernel panics and crashes.
    We had pitiful uptimes on our Solaris dev network because of this.

  - Clearcase is so complex, you'll need a Clearcase admin.  Versioning
    should not be *that* complicated.

  - complicated and nonintuitive tools.  Again, hence the admin.  (When I
    used it, we were amazed when ViewCVS et al were released.   Why were
    we paying so much for Clearcase again, when it couldn't even provide a
    CGI interface?)

  - since it's based around a kernel module, portability sucked: and when
    using it on an unsupported platform, the only way to do it was by
    NFS-mounting a Clearcase "view".  slooow.

All in all, I'd say steer *well* clear of Clearcase.  It looked nice on
paper, but the implementation (hello? using NFS as the transport!?!) was
total crud.

Everyone I know who worked closely with Clearcase, later moved on to use
other versioning systems.

However, I've heard people say that they've had good CC experiences;  I
think what you need to do this is

	- assign fulltime staff to administer Clearcase and the software
	  processes it'll require, and

	- throw vast amounts of $$$ at the problem

If you want a really nice commercial versioning system, Perforce (IMO)
kicks its ass.  We've been using it where I work now for the last 3 years,
and it's just fantastic -- and I still find little features, now and
again, that just make perfect sense.  It's small, well-designed, simple,
and a cinch to install and admin.