Alexey Solofnenko blog

I do not know about all people, but in my group everybody hates XML diff that ClearCase automatically launches for XML files. I remember vaguely there is a configuration file to tell what program should be launched for some file types. Instead I prefer quick and dirty method - replacing XML diff executable with text mode executable:
- locate xmldiffmrg.exe application in ClearCase installation folder (for example, "C:\Program Files\Rational\ClearCase\bin\xmldiffmrg.exe") and rename it
- copy cleardiffmrg.exe to xmldiffmrg.exe

and there is no more XML diff.

- Alexey.

Yes, I am well aware that ClearCase 6 does not work on Vista and I tried installing ClearCase 7 just to find out that our back system is still on ClearCase 6 (surprise!) and they do not talk to each other. But if there is a will, there is a way...

ClearCase 6 does not even install normally on Vista, so I had to trim it down to just client components - no MVFS nor view hosting. What can it do after that? It can connect to views hosted on other computers or create views with view storage areas on other computers. That is good enough. The command like cleartool mkview -snapshot -tag %USERNAME%-%COMPUTER_NAME%-view -vws \\ANOTHER_COMPUTER\SHARE$\%USERNAME%-%COMPUTER_NAME%-view.vws view. The view behaves as if it is a normal view and works correctly. The only problem I found - I was not able to check any XML files in. I had to change type for some of them to be treated as text files (I usually disable ClearCase XML diff anyway - I like to treat XML files as texts anyway) with command cleartool chtype -nc -force txt_file some/file.xml.

ClearCase was never designed to run on portable computers. It needs a static IP and ClearCase servers should be available during startup time. If it starts in a wrong moment, ClearCase services can freeze and only reboot will help. After few experiments I found the culprit - Atria Location Broker. It should be started only when VOB servers are available (after logging into VPN from home). The solution was straight forward - make it start manually and write a simple batch script directly in Quick Launch folder:

net start "Atria Location Broker"

Before using ClearCase, I had to press on the script icon and start ClearCase service. It worked fine and I added other commands into the script too - time synchronization with internal company time server, disabling beep net stop beep, update utility views,... But I do not use ClearCase from home any more - it is just too slow and remote desktop works just fine, so I now set Atria Location Broker startup to "automatic", but disabled it in "home" hardware profile.

Recently I had a problem with detecting loaded revisions in a ClearCase view. As it turned out, it was not what I thought. "cleartool ls -s -r -vob ../other_vob" does return correct revisions of files and directories that would be loaded, if the root VOB folder was linked. Before transition to a different script that generates my config specs, I had to add custom rules to handle other VOBs. I had two files - one for Windows and another for Unix (different VOB root path - "\" on Windows and "/vobs/" on Unix). I removed these custom rules from Windows file, but not from Unix one, so the script was still loading /main/LATEST on Unix (instead of a label). So this problem is solved.

However another problem is still present - how to get only loaded file revisions. I guess I will have to enumerate through all symbolic links (recursively for all VOBs) "cleartool find . -all -type l -vis -print", then check each link, where it points to: "cleartool desc -fmt %[slink_text]p slink", remove links that point into subdirectories of other links and request versions, first for the directory itself "cleartool ls -s -d -vob ../other_vob/path" and then for files inside: "cleartool ls -s -r -vob ../other_vob/path". It will be slower, but I need a reliable way to know revisions of all loaded files and ignore the files that are not loaded (and hence I do not care about them).

Because of that I do not actually know what revisions of what files are loaded from other VOBs. I have fixed config spec generation for such situations, but automatic build still detects wrong changes (the revisions are not loaded, because a label is used, but automatic build sees the changes). It is frustrating. I fixed that before by executing "cleartool ls -s -r -vob ../other_vob", but it always returns "LATEST" changes, not what is actually loaded by config spec. "-vis" option does not work, because the VOB root folder is not loaded. "cleartool ls" in ClearCase 7 also does not have -follow option. What do I do?...

ClearCase communication protocol is just horrible. It is completely unusable for my [big] project over VPN. Single file commit can take 10 minutes (and I am not sure, if project size affects it at all). After a long thinking about my difficult life, it just hit me - why not to use an existing network optimized protocol to access a ClearCase [snapshot] view on a server? Choosing Subversion protocol would make integration simple. The gateway does not have to be too pedantic to publish every ClearCase feature and even update to clients. On some schedule a snapshot view is updated on a server. If there are any changes, internal revision number is incremented, check in comments are collected (without duplicates) and used as that revision comment and ClearCase is asked for diffs between old and new revisions. What could be simpler? Any changes before that view construction are of no interest, so the initial view content would be the base line (revision 1?). Of cause, there will be problems with commits. It would require user impersonation to perform commits in ClearCase (otherwise all commits will be done with user running the gateway server). Also commit conflicts will have to be dealt with - files being checked in may be updated in other views, so the commit will fail, but this problems can be dealt straight forward without much problems (except, I would not use Java for the web server - user impersonation may require low level OS API calls, at least it used to).

They improved WAN speed by adding something called "remote client". While this change will be very welcome by many people, local speed is not fast enough. It takes about 7 minutes to update my view even if there are no changes.

Also I hope they provided "cleartool" command line tool for remote and web clients, otherwise our scripts will not be able to support these kind of views making them useless in our environment.