Migrating away from Clearcase

Question

We are migrating from Clearcase to another VCS (probably either SVN or Mercurial). For companies that have made this transition, what factors did they find important in selecting another VCS tool, and what practices did they find eased the transition?

Answer 1

SVN and Mercurial are both good SCM. Many opensource projects use them. If your choice only narrowed down to these two then what you and your team must consider is:

Workflow and workflow

How do you want to do the commits and branching? Distributed or Purely centralized? This is related to the company policy too. Go with SVN if you want everything to be centralized. But this does not mean you can not have central repository with Mercurial. It's quite beneficial if your team choose DVCS like Mercurial because:

• Everyone has their own local copy. This enables them to work from home and do local commits
• Everyone can do local branching in their local machine. Do not fear about merging between revisions, Mercurial has good support with merging and relatively easy compared to SVN.
• Not everyone must have commits access, because you can appoint someone to be a gatekeeper which pulls revision from other developer's machine. This enables you to do code review before submitting the code to the central repository.

Other than that, both are really good as they both have good (enough) performance, good windows support (SVN, Hg) and good documentation/book (SVN, Hg).

Answer 2

A couple to add are:

• Performance: slow development tools interrupt the developers' thought processes
• Power (Functionality): How good is merging? Newer tools like git have much better merge support and tracking than old-style tools such as CVS and SVN. Git also offers very handy tools such as bisect that speed the development process.
• Community support: How widely accepted is the tool? You don't want to pick something that will be on the sidelines five years down the road.