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  1. <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN"
  2. 	"http://www.w3.org/TR/REC-html40/strict.dtd">
  3. <HTML>
  4. <HEAD>
  5. <TITLE>SCM Evaluation</TITLE>
  6. <META NAME=AUTHOR CONTENT="Mike Meyer">
  7. </HEAD>
  8. <BODY>
  9. <H1>SCM Evaluation</H1>
  10.  
  11. <P>In choosing a SCM for this client, the primary requirements were:</P>
  12.  
  13. <OL>
  14. <li>It works well in a distributed environment.</li>
  15. <li>There is a server available for Solaris.</li>
  16. <li>There are clients for Solaris, Windows and the Mac.</li>
  17. <li>There is a GUI interface for Windows.</li>
  18. <li>The administrative and hardware costs are acceptable.</li>
  19. </ol>
  20.  
  21. <p>Secondary requirements included a WWW interface for examining
  22. documents and some form of change request tracking.</P>
  23.  
  24. <P>After considering several different systems, the Perforce SCM tool
  25. was selected as the most likely candidate. I installed the server on
  26. one system, the client on a few others, and used it for some simple
  27. projects. It worked quite well in those tests. While I encountered
  28. problems, the Perforce tech support group resolved them quite quickly,
  29. including providing client libraries for a new platform on short
  30. notice. Based on this, I recommend that this client install Perforce
  31. on one of their servers, and start using it on a test basis for parts
  32. of the existing web content.</P>
  33.  
  34. <H2>Systems Considered</H2>
  35.  
  36. <P>A search - including several web search engines and querying
  37. developers using these systems - turned up several systems to check
  38. on. They are presented, with a quick overview, in alphabetical
  39. order.</P>
  40.  
  41. <H3> BitKeeper</H3>
  42.  
  43. <P>BitKeeper would have been the most promising of the systems, but
  44. was not yet available for production use. BitKeeper designers targeted
  45. OSS projects. The designers assume distributed developers, with the
  46. number of developers running from a few to thousands.</P>
  47.  
  48. <H3>ClearCase</H3>
  49.  
  50. <P>The most capable system considered was ClearCase. It is also very
  51. expensive in terms of administration and hardware costs. The consensus
  52. of the people using ClearCase was that it generally required both a
  53. dedicated person and a dedicated system. These costs are unacceptably
  54. high for a SCM for this client.</P>
  55.  
  56. <H3>CVS</H3>
  57.  
  58. <P>CVS was the second most promising system examined, especially
  59. considering the pricing. However, I could not find a Windows 95
  60. client. Further, the <EM>module</EM> system CVS uses for labeling
  61. parts of a source tree complicates Unix client configuration. As a
  62. final strike, the job tracking system consists of programmatic hooks
  63. to connect CVS to an external job tracking system.</P>
  64.  
  65. <H3>Perforce</H3>
  66.  
  67. <P>Perforce is the most promising of the systems considered, meeting
  68. all of the primary and secondary requirements. I installed and used
  69. the server and client software for some small projects for evaluation
  70. purposes. The details on this can be found below.</P>
  71.  
  72. <H3>PRCS</H3>
  73.  
  74. <P>PRCS does not have support for a distributed work environment, and
  75. is thus totally unsuitable for this client. Version 2.0 is supposed to
  76. support a server that remote clients would use to reach the source
  77. code.</P>
  78.  
  79. <H3>VSS</H3>
  80.  
  81. <P>Visual Source Safe has marginal support for a distributed work environment
  82. Support for clients other than Windows is from third parties, which is a rich
  83. source for version conflicts. I heard numerous reports of VSS losing files.</P>
  84.  
  85. <H2>Evaluation of Perforce</H2>
  86.  
  87. <P>Obviously, the first step was to install Perforce. They distribute
  88. the production software with a <EM>default</EM> license that allows
  89. two users and two <EM>workspaces</EM>. The installation consisted of
  90. copying the two binaries into place, and arranging for the server
  91. software to run at boot time. Configuring the Unix client software
  92. consisted of setting a few environment variables to tell it where the
  93. server was, and what my preferences are. This took no more than a few
  94. minutes, total.</P>
  95.  
  96. <P> For the next step, I took a small project - just a few files - and
  97. put it under the control of Perforce. I then continued working on the
  98. project, using the Perforce commands where appropriate to notify the
  99. Perforce system about the state of the work. While this wasn't
  100. unobtrusive - the very nature of an SCM requires some intrusion - it
  101. was about as painless as I could imagine it being. When I needed to
  102. edit a file, I issued one command. If I forgot that step, the system
  103. prevented me from writing on the file, as the file was write-protected
  104. at the system level. After informing Perforce that I wanted to edit
  105. the file, it was writeable. When I finished editing and testing the
  106. file, I submitted the change too Perforce. It started an editor (that
  107. I specified at configuration time) on a form that had fields to state
  108. the files that had changed, and what the changes did. This was the
  109. least painful SCM system I've ever used.</P>
  110.  
  111. <P>For the next step, I moved to a system elsewhere on the internet,
  112. and installed the client there. I then repeated the above process,
  113. running the client and server on systems separated by of two
  114. firewalls. Excepting the initial setup - which involved copying
  115. multiple files - the response was not noticeably slower than doing the
  116. work remotely.</P>
  117.  
  118. <P>As a last test, I changed work modes. I added the files on the
  119. remote server to the local workspace, and started working on them
  120. there. After I was done with a change, I submitted the change to
  121. Perforce, moved back to the remote system, and synchronized that
  122. workspace with Perforce. While not quite as painless as doing things
  123. on only one system, it still worked well.  I don't see that this would
  124. have been different from trying to work in this way without an
  125. SCM.</P>
  126.  
  127. <P>To test the suitability of the Web interface to Perforce - known
  128. as <EM>WebKeeper</EM>, I installed that Apache module on an existing
  129. web server. This proved more difficult, as it required software for a
  130. platform they didn't support. I went to Perforce's tech support - via
  131. electronic mail - and asked about this. After discussing the various
  132. options, they provided a new version of the library about 24 hours
  133. after we identified the problem. This is typical of my interactions
  134. with the Perforce tech support group - timely, accurate response that
  135. solved the problem.</P>
  136.  
  137. <P>WebKeeper worked as advertised. It might take a little bit of work
  138. to make it fulfill all our needs.  However, if this proves difficult,
  139. or impossible, this is not a critical requirement.</P>
  140.  
  141. <H2>Recommendation</H2>
  142.  
  143. <P>This evaluation shows Perforce as an excellent fit for this
  144. project. I recommend setting up a small project that involves two
  145. people on two platforms under Perforce, as described in the main body
  146. of the document.</P>
  147.  
  148. </BODY>
  149. </HTML>
# Change User Description Committed
#1 224 Mike Meyer Add pdf & xhtml versions of the Scheme Evaluation I did for EPRI. 26 years ago