Talk:Rational ClearCase

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Editing this page[edit]

If you are knowledgeable about SCM you will notice a large part of this page is utterly nonsense. However, like pages on religion or paranormal activities in wikipedia... it is no use adding or changing information here since some totally misinformed persons really like to have this page in certain state for unknown reasons. —Preceding unsigned comment added by (talk) 05:39, 22 April 2010 (UTC)


This part seems wrong:

> Transactions not atomic: Changes to files or directories are independent from others, unlike some other systems where multiple changes can be committed atomically at the same time, using the concept known as Changeset. Atomicity is desirable because it allows multiple changes that address a particular problem to be committed as a single unit, and, provided the developer has been careful, results in a buildable code base for every version.[6]

I distinctly remember working with change-sets in ClearCase. —Preceding unsigned comment added by (talk) 07:45, 2 December 2007 (UTC)

Sure - it's easy to cite:
Note that the wikilink doesn't really point to a discussion of "ChangeSets", but to "Atomic Commit" - something different. However, look back to the history where that detail was introduced apparently by the IP-editor who's been hacking at the article recently - there's been other debris removed from that edit. Tedickey 20:21, 2 December 2007 (UTC)
Transaction are NOT atomic. Sure - you a have a change-set of a commit (called delivery), but it is not atomic. If the process stops or is being cancelled midway, no rollback is being performed. That's the definition of atomic in my book. OmerMor (talk) 17:07, 27 July 2009 (UTC)


no comparaison against other SCM ? This page looks too much like ClearCase marketing... No mention of its *extremely* slow speed, unfriendly user interface and terminology?

terminology??? Ever used an RDBMS at all? --Afc 03:15, 28 July 2006 (UTC)
The friendliness of a user interface is subjective. I like most of it. Jgrahn 19:54, 13 April 2006 (UTC)
It's very well designed and not at all unfriendly, but indeed it requires resources in terms of computing power and performant io disks -- mlz
No dev can argue that it is "well designed" and "user friendly", that is simply false. I enjoy its positive sides (stability, support for large development organizations) yet it is slow due to its old architecture and suffers severely bad usability (can you say "modal dialogue layering"?) - I have never found any usability engineer or any dev with competence in usability argue otherwise, simply because they break a host of usability principles. Again, the product has positives. - Marcus Widerberg / senior dev
—Preceding unsigned comment added by (talkcontribs) 20 June 2006
The Senior Dev guy is probably talking about the Windows GUI, and I tend to agree there. I was (as User:Jgrahn) talking about the Unix command-line, version-extended pathnames, manpages and so on. JöG (talk) 07:59, 16 February 2008 (UTC)

How can I know the all the files checked in by an induvidial[edit]

How can I know the all the files checked in by an induvidial?

If you're looking for the specific ClearCase command, it is: cleartool find -avobs -version "created_by(username)" -print (read the find and query_language manuals for details) Trent 15:40, 28 March 2007 (UTC)

Reputation of reliability... hum that's not that I saw with 3 different clients. It is used in big project (because from IBM) but it's not more reliable for that.


The same here. Entire days of downtime for server problems. Because the files exist only on the dynamic view, it is not even possible to work on the local copies of the files. But it is from IBM so it must be good. (talk) 04:04, 12 December 2007 (UTC)


At some point, I would like someone to explain to me exactly how ClearCase integrates well with Rational Rose, ClearQuest and other IBM/Rational tools. In my experience, those other tools resist any kind of serious revision control. Jgrahn 19:58, 13 April 2006 (UTC)

Jgrahn, Rose integrates quite well with ClearCase, you can invoke most of the ClearCase functionality from its integration menus. I cannot believe you're talking seriously about ClearQuest integrations, since it complements CC functionality, and it's data is not really meant to go through version control. If you were ever near Rational Software Architect (or plain vanilla Eclipse, btw) you can see some other nice example of integration with ClearCase.

Afc 23:07, 18 March 2007 (UTC)

It's been a long time since I wrote that, but concerning Rose: IMHO to "integrate" with ClearCase, you need to do more than adding a menu items with invokes "cleartool co" etc. Solving (not just claiming to solve) the merge problem would be on the top of my list. JöG 21:44, 6 November 2007 (UTC)

From version 7 ClearCase and ClearQuest are now one product. They share the same API and in the CCRC you have both CC and CQ with a single sign on function. They talk to the same CM server (running in WAS), so you only need 1 server for both (or multiple chained next to each other). —Preceding unsigned comment added by (talk) 05:43, 22 April 2010 (UTC)


Rather than a "criticism" section (ClearCase is not a person, as much as I'd like to anthopomorphize it), I think we should definitely add a pros/cons section that references the SCM tools comparison. --Afc 03:15, 28 July 2006 (UTC), a very biased source.

As others have said here, this article reads like marketing blurb for the product. I think it should contain at least a section of "criticisms" -- I am a professional software engineer and have heard many. Alf Boggis 12:03, 31 May 2006 (BST)

As someone new to ClearCase and the article, I have to say the article reads more like a "ClearCase is SCM and this is what makes it unique". I do believe this is article is more NPOV than positive-POV, and it helped me understand why my company has decided to use it. However, before I erected a ClearCase service I'd prefer someone make a Criticisms section (even though CC is too expensive for me to buy just because of a Wikipedia article). --Caidence 15:28, 12 June 2006 (UTC)
I added links to "List of revision control software" and "Comparison of revision control software".--Btwied 17:01, 14 June 2006 (UTC)
A criticism section would be great, I also have heard many criticisms of ClearCase. There must be some published articles out there that could be referenced. --JRavn 23:02, 24 July 2006 (UTC)
I should clarify that the criticisms I have heard are with the UCM and the Windows GUI parts rather than basic ClearCase Alf Boggis 14:11, 27 July 2006 (UTC)
I could certainly write up a criticisms section, as I have been working with ClearCase (as an admin) since 1994 and am very familiar with its flaws (and advantages, of course). But wouldn't that count as original research? Maybe I'll finish up the critique page on my own website first. Trent 15:36, 28 March 2007 (UTC)
Funny how the criticism section disappeared recently (considering it was pretty mild) Tabgal 00:05, 15 October 2007 (UTC)
Contributions show only the one change by the IP that did the edit. Presumably someone will add it back (preferably someone who's actually familiar with the product ;-) Tedickey 00:18, 15 October 2007 (UTC)

I have issue with this statement:

Unix/Windows Interoperability: VOBs hosted on *nix (Solaris, Linux, AIX, HP-UX, IRIX primarily) servers can be accessed from views hosted on Windows clients. VOBs hosted on Windows servers can only be accessed by Unix clients with snapshot views.

Isn't that statement a con--that you can't use the same access methods in multiple operating systems? (talk) 11:20, 16 April 2008 (UTC)

It seems to be only commenting that (while the product provides some degree of interoperability) there is a limitation of the Windows server implementation. The second sentence could be (assuming it's reliably sourced...) moved to weaknesses. Tedickey (talk) 11:28, 16 April 2008 (UTC)

Are references to third party patches acceptable (disclamer I wrote it)? The reason dynamic views on a *nix client fail when the VOB is hosted on Windows, is because windows returns the path backslash separated instead of the *nix forward slash, that's it. Is it appropriate to say why the dynamic views fail?

Unix/Windows Interoperability: VOBs hosted on *nix (Solaris, Linux, AIX, HP-UX, IRIX primarily) servers can be accessed with dynamic views, snapshot views, or the new web protocol based client: the CCRC on Windows clients. VOBs hosted on Windows servers can be accessed with snapshot views or CCRC from Unix clients, but not dynamic views due to the Windows server returning file strings with backslashes as the path delimiter. There is a 3rd party patch [1] for Linux to work around that issue.

Dfries (talk) 00:56, 26 July 2009 (UTC)

The reference to Dfries' patch is great, but I still think the statement is overall a con, not a pro, and should be moved. Mugwump55 (talk) 09:48, 5 May 2011 (UTC)

This article reads like "CC is the greatest SCM system, it can handle thousands of developers!", etc. I worked on two projects using CC and got very mixed impression about CC. Arguments about number of developers and number of lines handled are bogus: no project should require that many developers and lines, and this is rather indicative of the project bloat. Both projects managed by CC that I saw failed and were discontinued mostly because of unmanageability. In fact CC feels over-engineered, views in it aren't necessary, I saw people working full time fixing paths in broken VOBs, and in fact svn or similar systems will perform the same or better even with that many developers. Article should be made NPOV, and more neutral. Yurivict (talk) 22:38, 30 March 2010 (UTC)

Yes it can be very true that you witnessed projects that failed. I see a lot of projects fail that do not even use a CM system... that is because a large amount of IT project fails for all kinds of reasons. SVN will not perfom the same or better that is your bias. If you goto the faq page on SVN itself you will read why it was setup and with which reasons. To be a open source replacement for CVS NOT to be a complete CM replacement... And certainly not with that many developers. These are not emotional discussions it are just statistics. About 100% of the top N companies in every sector use it. First check your facts. And yes if I would just leave apache, drop WAS, strip everything 99% of the functionality out of ClearCase leaving only an API, tell my developers to only use hijacked files then... I would svn... I can build that thing inside ClearCase dropping 99% of the functionality. As a configuration manager however I would go crazy. —Preceding unsigned comment added by (talk) 05:50, 22 April 2010 (UTC)

No, you are wrong. There are many industries that don't (or almost don't) use ClearCase. Electronic Design Automation is one example, chip design area is another one. You are drawing your conclusions from your personal exposure to ClearCase. And you have missed my point: many developers doesn't mean large scale industrial project, many developers means bloat and death. I saw many such cases. But you as an SCM manager would not be exposed to this because that's your job to manage repositories no matter what is there. Here is where your bias comes from. Yurivict (talk) 21:41, 8 May 2010 (UTC)

Weaknesses section has weasel words[edit]

This section is poorly written, e.g. "unlike recent SCM, you cannot commit a bunch of files" and "they accumulated a ton of code and are based on old architecture that make them slower and difficult to use that they could". All the weaknesses are rather subjective, and don't have any citations. Hertzsprung 17:21, 29 August 2007 (UTC)

It's not just weasel words, it's absurd. Who can tell how much legacy code ClearCase contains? Who waits for minutes for "the simplest changes"? What version control tools (except RCS and SourceSafe) cannot easily be used to generate "excessively complex" systems of information? Who cares if transactions are atomic, when she is alone on her own branch? Et cetera. JöG 21:56, 6 November 2007 (UTC)

I care about atomicity, even when I'm alone on my own branch. Ever had a network failure in the middle of a commit? —Preceding unsigned comment added by (talk) 09:08, 6 December 2007 (UTC)

What exactly counts as a credible citation? I don't believe that any neutral scientific papers would publish criticisms of consumer products and the management-oriented magazines are not going to bite the hand that feeds them. I could make a benchmark that shows how fast (not!) Clearcase is on a reasonable corporate network, but would anybody believe it? By the way, I can't believe that the facts that the dynamic just disappear when connection to server is lost and that Clearcase running dynamic views does not survive changing IP address (DHCP and laptops, anybody?) are not mentioned. No I agree that the Clearcase Explorer looks pretty fine until one attempts to use it and the Version Tree tool is actually good, but the drawbacks make Clearcase unusable. Now of course one can work around bad tools. I would rather work on hard problems using good tools. (talk) 04:04, 12 December 2007 (UTC)

I used CC from '98 to '03 or there abouts. I had three complaints

  • it was expensive.
  • dynamic views needed serious network capability and really good work habits. I just used snapshots and an out-of-band update notification mechanism
  • its multisite support was primitive and painful to use. Away from The Server you basically lost all revision control, even with snapshots

Don't know what's like now - current work environment uses something positive neolithic. —Preceding unsigned comment added by Thoglette (talkcontribs) 14:48, 1 September 2008 (UTC)

Weaknesses Citation is from a competitor[edit]

I have an issue with citation 12, which apparently justifies this paragraph :

"Speed: ClearCase dynamic views are slower than local filesystems, even with good network infrastructure. A benchmark shows that many basic tasks take about twice as long to run using a ClearCase dynamic view than on competing SCM tools. Basic operations on snapshot views can take more than ten times as long as on competing systems. Although initial builds using dynamic views require roughly twice as much time versus using a local filesystem [12],"

If you look at the source in 12 it is made by a competitor. Having used clearcase I know it is slow, however if I was a new user I would not trust a competitor's marketing data as the best information. -mike

Yes, I wrote that piece and I know. If you know of an independent benchmark, please cite it. The problem is, you can not just make benchmarks yourself and publish them because that would count as original research. Usually version control benchmarks do not compare build times because the entire idea that accessing files in source control would be slower is so absurd.

In my experience, those numbers are rather biased to favor ClearCase. Where I work, compiling on dynamic view takes about 2.5 times as long as on a plain file system or CC snapshot view. And that's on a slow encrypted hard disk. I would not believe it myself if I didn't have first hand experience. (talk) 12:24, 18 January 2008 (UTC)

I added a reference and some information concerning speed-performance for windows clients. Erapade (talk) 22:17, 30 January 2008 (UTC)

I agree that the speed issue is worse than even Perforce was willing to claim. We found a minimum 2.5x slowdown on everything, even with a good network. On a slow network, it was completely unusable, even with snapshot views--over our in-house (and not too bad) intercontinental WAN connection, it would take days to check out any sort of complicated snapshot view. Even a trivial one took hours. —Preceding unsigned comment added by (talk) 13:46, 11 March 2008 (UTC)

I think most criticism here is due to lack of knowledge of the product. I have been a user of ClearCase since 1997. I used both snapshot and dynamic views and set it up in two companies without being an administrator. The claim that creating a snapshot takes a long time is, I'm sorry to say, BS. For dynamic views, yes, your network may need to be tuned a little. If you have a good admin, it is no problem, he can find the network bottlenecks. I have met a lot of people that criticize CC without understanding the basic branch-work-merge paradigm. To me anyone who thinks branches are unnecessary don't understand version control. I have seen haters of ClearCase that insist on modifying the same file by multiple people at the same time. This goes against the concept of a "view" and a "branch". All I know is that the used all features of this tool including the "multi-site" aspect between France and USA. It works. You may not know how to configure and use it. That is your fault not the product's fault. - Oguz —Preceding unsigned comment added by (talk) 19:28, 20 March 2009 (UTC)

What possible network configuration would make access to a remote-mounted file as fast as native disk access? ALloydFlanagan (talk) 16:00, 16 February 2011 (UTC)

More history[edit]

More information about Clearcase versions and corresponding dates is missing in my opinion. Does anyone have some information? It's difficult to find some on the Internet. (talk) 08:34, 25 July 2008 (UTC)

Yes but it is pretty much impossible editing this page because competitors will keep changing this page back to page full of nonsense. Don't look for objective information on wikipedia. —Preceding unsigned comment added by (talk) 05:57, 22 April 2010 (UTC)

You are quite right about objectivity, Mr. I just looked at your revision history and you have basically done little more than puff up this product. Objectivity? geezabrek... — Preceding unsigned comment added by (talk) 14:51, 20 March 2012 (UTC)

Nothing unique about majority of features[edit]

I changed a title from "Unique Features" to "Features", because clearly there is nothing unique in at least majority of the features listed. These are VOB, Interoperability, Integration. It may not be called VOB, but other SCM systems also maintain the data present in the VOB. (talk) 11:00, 15 January 2009 (UTC)

It's not brought out clearly in that section, but go up to "Views". What was novel about the VOB was that it was implemented as a virtual filesystem. DSEE was implemented using one of Apollo's features, the ability to have customized filesystems (an example would be compressed files, encrypted, etc. - the Apollo feature dated from the mid-1980s). When ClearCase was implemented, it made this available in a more/less portable implementation, not relying on the Apollo features. Tedickey (talk) 12:07, 15 January 2009 (UTC)


I've been using clearcase for over a decade and I can say that this section is clearly BS. Clearcase is a large expensive product, which requires loads of resources/bandwidth to use correctly. It reads as though it's been written by a competitor, Perforce and uses weasel words. It begs the question, why would somebody put a weaknesses section in. Taking each point in turn.

  • Transactions not Atomic. That is BS in its purest form. It would invalidate the whole concept of CM if this was the case, and is using its standard operation as a weakness.
  • Aging. "have stagnated and accumulated significant quantities of legacy code". So what, all apps have legacy code, that is one of the fundamentals of software development, a common concept, but not a weakness. "ClearCase was designed to support existing build systems rather than require the developer to use only ClearCase tools such as clearmake." A design choice isn't a weakness. The fact you could use your own build tools, and optimize the CM process for your own shop was a selling point.
  • Speed. "dynamic views are slower than local filesystems" That was probably the case in older versions, but generated view for any app, across a network, unless your using 100Mbit or 1Gbit ethernet will be slower. Its a high end product.
  • Speed - Windows clients. "meaning this is a historic argument.". Clearly a case for History of Rational ClearCase, not a salient view of the current product.
  • Sensitivity to network problems. The catchall. Show me an app which operates online, which is now the majority of them, which is not sensitive to network problems. That is a completely redundant bullet point.

If the sections it really needs to be radically overhauled. Personally I think it should be removed. scope_creep (talk) 17:46, 1 April 2009 (UTC)

The section should be removed as it offers no real value. scope_creep (talk) 17:46, 1 April 2009 (UTC)

I have been using clearcase for over a decade too, and the weaknesses section is too mild in my opinion:
  • Speed. It is extremely slow, even in snapshot views (every single operation takes time because it has to go over the network). Compared to svn or git which are also free is has no single advantage. SCM should be fast enough to be unnoticeable by the developers. CC is extremely noticeable.
  • Maintenance and Reliability. This tool is the epitome of high-maintenance. It breaks on every occasion. You must have a full-time CC administrator on-site to make it work.
  • Price. Very expensive tool, and the free tools are not only free but also better in every aspect.
I am subjective of course - but I also talk from lots of (painful) experience. OmerMor (talk) 17:24, 27 July 2009 (UTC)

You are so far from reality that I don't know even where to begin. —Preceding unsigned comment added by (talk) 06:00, 22 April 2010 (UTC)

You can't discuss price without including a citation that compares it to other similar products. To say it is expensive compared to free opensource products is not appropriate. SVN should also be added as "Subversion" with a link.

Maintenance is also factually incorrect and subjective. We operate the largest ClearCase implementation in europe with only 2 administrators. It would be better to say that the product is complex and requires 3-5 days classroom training in order to perform administrative duties. You can cite IBM Rational's Training Xantiriad (talk) 10:07, 30 July 2009 (UTC)

I, too, must lend support to those pointing out that it's being maligned for being a big, complex product that has to be deployed appropriately. When properly deployed and managed, it is quite usable and reliable. I would go so far as to say that it doesn't even require a full-time admin once it's up and running - I speak from experience, having used and administered the product extensively. The documentation is complete and accurate, and the sophistication of the versioned object model and branch/merge capabilities (and the real-world development benefits derived from them when used properly) are unmatched in any other SCM I've used in my multi-decade development career. Changing to an unbiased pro/con format would be a significant improvement. CorbaGuy (talk) 01:06, 18 December 2009 (UTC)

Atomic checkins are supported in ClearCase 7.1.1. —Preceding unsigned comment added by Clearcase user (talkcontribs) 20:57, 4 January 2010 (UTC)

The talk experience is misleading. I've also used Clearcase for nearly a decade in several large organisations, and I can confirm like so many other users that it is uniformly slow, resource consuming, and especially in dynamic mode, unstable due to heavy reliance on networking. Dynamic views is a bad idea, that is a source of all kinds of problems. It is not uncommon a whole team is completely unable to work due to a network problem. No wonder DVCS like git and Mercurial, which are the cream of the crop, have taken the exact opposite direction. Clearcase is usable in snapshot mode, it just offers no advantage over the current crop of DVCS.

A link to[edit]

Hi, I am not an experienced Wikipedia editor, so maybe you could help me. There's a link here to . To the best of my understanding of ClearCase the information there is OK, but the external links policy says that links to forums should be avoided. Can I remove it then? And if I remove it, should I replace it with "citation needed"? Thank you. Kurepalaku (talk) 17:34, 31 May 2011 (UTC)

That's ostensibly sourcing the explanation of the abbreviation. However, the linked topic in the statement already provides a reliable source. So there's no need for the stackoverflow link, nor is a citation needed. ( by its nature isn't WP:RS in any case) TEDickey (talk) 21:19, 31 May 2011 (UTC)

use of WANdisco advertisement as a source[edit]

This topic has changed since the WANdisco advertisement was added ostensibly to support the statement that "MVFS requires server access every time a file is accessed". The source given doesn't support the statement (and reading WANdisco's page, it's apparent they did no benchmarking, etc., to justify the source). TEDickey (talk) 21:57, 3 June 2011 (UTC)

Non standard terminology[edit]

I think that ClearCase uses non standard terminology which is often confusing for users more familiar to other version control systems, however I cannot find any really authoritative sources that say so. However I have seen the same thoughts echoed on many forums, so is it wrong if I added the statements to the afore mentioned effect to the article? Gulielmus estavius (talk) 19:23, 30 March 2012 (UTC)

Put another way, ClearCase preceded a handful of widely-used systems whose developers have based their jargon on a different source. "non standard" per se would only be an appropriate comment if there were some official standards-setting body making suitable pronouncements on the matter TEDickey (talk) 20:58, 30 March 2012 (UTC)
Ok I can't call it non standard terminology, but could I call 'unusual terminology' ? Gulielmus estavius (talk) 18:15, 31 March 2012 (UTC)
Probably not. Jargon is often unusual to people who haven't been using a particular flavor. It's best to look for WP:RS which are reasonably independent (there's no point in sourcing something like that to developers or fans of whatever seems popular). TEDickey (talk) 18:41, 31 March 2012 (UTC)

removing POV tag with no active discussion per Template:POV[edit]

I've removed an old neutrality tag from this page that appears to have no active discussion per the instructions at Template:POV:

This template is not meant to be a permanent resident on any article. Remove this template whenever:
  1. There is consensus on the talkpage or the NPOV Noticeboard that the issue has been resolved
  2. It is not clear what the neutrality issue is, and no satisfactory explanation has been given
  3. In the absence of any discussion, or if the discussion has become dormant.

Since there's no evidence of ongoing discussion, I'm removing the tag for now. If discussion is continuing and I've failed to see it, however, please feel free to restore the template and continue to address the issues. Thanks to everybody working on this one! -- Khazar2 (talk) 00:43, 17 June 2013 (UTC)