






                    Aegis is Only for Software,

                             Isn't It?

                            Peter Miller
                      millerp@canb.auug.org.au



         Aegis  is a Software Configuration Management sys-
         tem, which provides a method for managing  concur-
         rent  development  and  peer  review  with  strong
         auditability.  These features are useful  to  more
         environments  than  the  development  of software.
         This paper presents two systems being managed with
         Aegis at AGSO: DNS and the Web.

         Using  Aegis to manage DNS provides a reliable way
         to add  entries  to  the  DNS  tables,  check  the
         tables, and generate the reverse maps.  It is even
         generating some NIS+ tables.  The system  is  peer
         reviewed, so no ``broken'' changes are able to get
         into the system tables.  The net result is a  more
         reliable service to the users.

         Using   Aegis  to  manage  the  AGSO  Web  (http:-
         //www.agso.gov.au/) models the production of  sci-
         entific papers.  In the normal publication process
         an author writes a  paper  and  it  is  then  peer
         reviewed,  the  reviewers  may return it with com-
         ments or approve it to the  publisher.   The  pub-
         lisher  in  turn  may accept it for publication or
         return it.  A similar  model  is  available  using
         Aegis  when  publishing Web pages; the publication
         analogy is deliberate since  the  work  is  indeed
         available to the public.  The ``build'' step which
         is so central to producing software is used in the
         Web case to resolve server-side includes, to check
         the HTML for obvious errors, and to  generate  the
         various  indices.   Some  Aegis  reports  are also
         used, such as the  one  from  which  the  ``What's
         New''  page  (http://www.agso.gov.au/whatsnew/) is
         generated.  The provision by Aegis  of  individual
         ``sand   pits''   greatly  facilitates  concurrent
         development of Web pages and  improves  productiv-
         ity.   In  general, staff have been happy with the
         Web development model in use at AGSO.









    Peter Miller                                          Page 1





    AUUG'96                Aegis is Only For Software, Isn't It?


    11..  AAeeggiiss aatt aa GGllaannccee

    The  term  _C_o_n_f_i_g_u_r_a_t_i_o_n  _M_a_n_a_g_e_m_e_n_t was coined many decades
    ago in  the  engineering  disciplines.   It  refers  to  the
    process  of managing all of the components of an engineering
    design.  In designing a car, for example, it is important to
    know  which  version  of the shock absorbers goes with which
    versions of the chassis and wheel arches.

    A similar problems exists for the construction of  software,
    and so the term was borrowed by software engineers to become
    _S_o_f_t_w_a_r_e _C_o_n_f_i_g_u_r_a_t_i_o_n _M_a_n_a_g_e_m_e_n_t_.  This refers  to  keeping
    track  of  the various source components of a software pack-
    age, and how to assemble them into a working program.

    There is a huge similarity  between  assembling  a  software
    program,  and  assembling a web.  Source files are processed
    and stitched together to form the final  product,  much  the
    same  way  program  source  files  are  compiled  and linked
    together to form the final software product.

    Aegis is a software configuration management system, and  it
    provides  controlled  accesses  to  the  source  files  of a
    project.   It  can  support  concurrent   development,   and
    enforces mandatory reviews.  As Aegis is described more com-
    pletely elsewhere [1, 2], this  paper  will  not  dwell  too
    heavily  on how to use Aegis, but rather how Aegis is useful
    in the two case studies below.

    22..  DDNNSS MMaannaaggeemmeenntt

    The first case study presented here is that of  using  Aegis
    to  manage Domain Name Service (DNS) information.  This is a
    relatively small system, it is reasonably well known, and if
    you  get  it  wrong your network may cease to function until
    you get it right again.  DNS itself has been described else-
    where [3, 4] and will not be described in depth here.

    The  design  of  the Unix _n_a_m_e_d(8), the program which serves
    the DNS protocol,  is  intriguing,  mostly  because  of  the
    almost-but-not-quite  redundancy  in  most of the configura-
    tions files.  This revolves around the  fact  that  DNS  has
    both  _f_o_r_w_a_r_d  maps which associate a domain name with an IP
    address, and _r_e_v_e_r_s_e maps which associate an IP address with
    a  domain  name.  Naturally, if these maps are not carefully
    synchronized, a variety of problems  may  result.   This  is
    traditionally  solved  using _m_a_k_e(1) and some baroque _a_w_k(1)
    scripts.  The maintainer logs in as _r_o_o_t, edits the  forward
    map,  runs  make, and informs named that it needs to re-read
    its input files, usually by running  a  shell  script  which
    sends a signal to the server process.
    -----------
    Copyright  (C)  1996  Peter  Miller;  All   rights
    reserved.



    Peter Miller                                          Page 2





    AUUG'96                Aegis is Only For Software, Isn't It?


    But  what  do  you do when there is more than one authorized
    maintainer?  How do they coordinate  their  activities  when
    they  are  in  3 different buildings?  How do they make sure
    the configuration files are OK _b_e_f_o_r_e they bring  the  whole
    network to its knees?

    None  of these problems are particularly new or interesting.
    They are well known to software development teams the  world
    over.  At AGSO, we are using Aegis to resolve them.

    22..11..  CCoonnccuurrrreenntt DDeevveellooppmmeenntt

    Aegis  has the concept of a _b_a_s_e_l_i_n_e which is the known-good
    currently-working master source for a project.  Aegis parti-
    tions  alterations to this baseline into sets of files which
    must be altered simultaneously to  preserve  the  currently-
    working-ness of the baseline.  These sets of files may be as
    small as a single file, or as large as every source file  in
    the baseline.

    These  alterations  to the baseline are known, unoriginally,
    as _c_h_a_n_g_e_s, and each change is given a separate  development
    directory.   By  developing each change in a separate direc-
    tory, there is no possibility than one maintainer can  acci-
    dentally blow away another's work.  At worst, if they have a
    file in common, one will need to merge the other's work with
    his own.  This merge is fully supported by Aegis.

    The  other  important  feature of using separate development
    directories is that ``half finished'' changes are  not  mis-
    taken  for  valid  input,  should the DNS server be rebooted
    during the development of the change.   Until  a  change  is
    completed  _a_n_d has been reviewed, the baseline remains unal-
    tered.

         This entire process is performed by users logged in  as
    themselves.   Access  is  controlled by access control lists
    based on user names, no special  system  user  accounts  are
    required.   need  for users to login to a special account to
    work on web pages.

    22..22..  VVaalliiddaattiioonn

    When constructing software, the program  is  built  in  some
    way.  One traditional Unix approach is to delegate remember-
    ing how to do this to a  program  such  as  _m_a_k_e(1).   While
    _m_a_k_e(1)  can  be used with Aegis, the author prefers _c_o_o_k(1)
    as a more capable and descriptive build tool.

    The build step is used to translate the  forward  maps  into
    reverse  maps.   This is not done with _a_w_k(1) for a few rea-
    sons





    Peter Miller                                          Page 3





    AUUG'96                Aegis is Only For Software, Isn't It?


    +o    The SRRF input format used by _n_a_m_e_d(8) makes  for  very
         hard  to  read awk scripts if you are determined to use
         the full input language.

    +o    We use include files to describe our various  buildings
         and   other  internal  network  structure.   This  also
         reduces  the  number  of  opportunities  for  conflicts
         between changes.

    As  a  result, we have a suite of C programs (also developed
    using Aegis, naturally) which perform the  various  transla-
    tions and filters we require.

    A  very  important side-effect of these translations is that
    they validate their input.  In this we detect duplicate host
    names,  invalid  host names, duplicate IP addresses, invalid
    IP addresses, etc.  When we converted our DNS procedures  to
    use DNS, a number of problems were discovered which had been
    in the system for years.

    Yes, these problems could have been discovered with the  old
    root  make  system,  but  they  were not discovered until we
    decided to us a system specifically  designed  to  be  main-
    tained by many people, and to double check everything before
    it went ``live'' and inconvenienced staff.

    22..33..  DDeerriivveedd DDaattaa

    We also use the DNS  data  to  generate  some  of  our  NIS+
    tables.   Obviously,  the  NIS+ hosts table needs to be syn-
    chronized with the DNS tables, and this translation is rela-
    tively easy.

    We  also invented an ``ether'' type, which we filter out and
    don't  actually  give  to  _n_a_m_e_d(8),  to   record   Ethernet
    addresses.   This  information  is  used  to derive the NIS+
    ethers table.  This could have been managed differently, but
    as it is intimately related to the IP address management, we
    decided to do it here, for a sort of  ``one  stop''  network
    shop.

    The  hinfo  records  are _g_r_e_p(1)ed to generate the NIS+ net-
    group  table.   This  is  used  to   minimize   changes   to
    _/_e_t_c_/_h_o_s_t_s_._e_q_u_i_v, _/_e_t_c_/_d_f_s_/_d_f_s_t_a_b, etc.  As a new machine is
    added,  it  receives  a  formula  hinfo  description,  which
    results  in  it being included in the appropriate net group,
    and thus the appropriate network permissions.

    The hinfo records are also filtered  to  generate  the  NIS+
    bootparamd  map.  When combined with the hosts table and the
    ethers table, this is all that is required  to  configure  a
    workstation for the Solaris Install Server.





    Peter Miller                                          Page 4





    AUUG'96                Aegis is Only For Software, Isn't It?


    22..44..  RReevviieeww

    Aegis will not allow a change to finish development until it
    builds cleanly.  Thus, if there are any errors found  during
    the  various  filters  performed by the build step, a change
    may not end development.

    Once  a  change  ends  development  it  is  not  immediately
    installed into the baseline.  It enters a ``being reviewed''
    state.  Developers are prevented from  reviewing  their  own
    work,  as  an  obvious  conflict  of  interests.  Some other
    authorized review must do so.  The access control lists  for
    developers  and reviewers are separate, and it is up to your
    individual preferences whether they overlap or not.  Once  a
    reviewer OKs the change, it is then integrated.

    22..55..  IInntteeggrraattiioonn

    The integration involves making a copy of the baseline (usu-
    ally with hard links, it is faster) and applying the  change
    to  this  copy.  The build is performed again on this copy -
    mostly as a quick double check, though it does  not  in  the
    Web case, below.

    The  integrator  can  also  serve  as an editor, or a second
    reviewer if necessary.  It answers the perennial ``who  will
    watch the watchers'' question.

    Aegis'  notification  facility,  used  at most transition to
    send email or news articles, is also  used  at  the  end  of
    integration  to  notify DNS and NIS+ to re-read the relevant
    files.

    22..66..  OObbsseerrvvaabbllee RReessuullttss

    It was long suspected that there was a fairly high  rate  of
    change  in our DNS data, but we didn't track it too closely,
    we already had more than enough to do.   Aegis  tracks  this
    activity in a very non-intrusive manner.  At present, we are
    averaging 3.5 DNS changes per week, a figure not  previously
    available.

    The other thing which has changed is that there are no unex-
    plained changes.  You no longer hear they cry ``Who the smeg
    did  that?''  echoing down the corridor.  There is never the
    silent anonymous untrackable duel between two administrators
    undoing and redoing each others changes.

    By adding Ethernet numbers, we can detect when machines move
    between staff and between floors and change  names,  meaning
    that  we  can detect now-vacant IP addresses by the Ethernet
    address duplicate.





    Peter Miller                                          Page 5





    AUUG'96                Aegis is Only For Software, Isn't It?


    The most important result is  stability.   More  is  checked
    than  ever  before,  and  it is discovered earlier than ever
    before.  Only changes which pass all our  automated  checks,
    and  also  pass  the  scrutiny  of  a  human DNS boffin, are
    inflicted on users.

    33..  WWeebb MMaannaaggeemmeenntt

    The second case study presented is that of AGSO's Web.  This
    is  also  managed using Aegis, though this project has many,
    many more sources files.  The environment presented by Aegis
    is  the  same - though the terminology used is more aimed at
    authors than system administrators.

    The method of Web development  implemented  using  Aegis  is
    presented  as  an analogue of the publications of scientific
    papers.

                              Author
                          _w_r_i_t_e_s _w_e_b _p_a_g_e_s
                                 |
                                 |
                                 |
                                 |
                             Reviewer
                        _p_e_r_f_o_r_m_s _p_e_e_r _r_e_v_i_e_w
                                 |
                                 |
                                 |
                                 |
                              Editor
                     _p_e_r_f_o_r_m_s _e_d_i_t_o_r_i_a_l _r_e_v_i_e_w


    In particular, it is expected that much of the science  con-
    tent  of  our  web pages will be authored by out scientists.
    The peer review is expected to be, and should be,  performed
    by the scientist's science peers.  Everything else - layout,
    formatting, copyright issues, structure, etc, are  the  edi-
    tor's  problem.   Only  the  author may alter a change - the
    peer reviewer and the editor only have the  power  of  veto.
    The  file  system  permissions  are exploited to ensure that
    there is no ``back door' to this process.  Even  the  editor
    (integrator)  does  not  have write permissions to the base-
    line.  All changes to the baseline _m_u_s_t traverse the  entire
    change process.

    33..11..  BBuuiilldd aanndd VVaalliiddaattiioonn

    The  build  step in the Web project is very little different
    from the build step in the DNS project.  We  use  the  build
    step to:





    Peter Miller                                          Page 6





    AUUG'96                Aegis is Only For Software, Isn't It?


    +o    Resolve  server-side  include  files, so that the files
         fetched by external clients are complete, and the  HTTP
         server can be as dumb as possible.  We use common head-
         ers and footers in common include  files  to  implement
         much of the look and feel of our web pages.

    +o    Perform  SGML  checking  against the HTML 2.0 DTD.  The
         finds all of the overt HTML errors, but it cannot check
         spelling  or  style.  We use _s_g_m_l_s(1) obtained from the
         network, and the standard html.dtd also  obtained  from
         the network.

    It  takes longer to perform this build than in the DNS case,
    because there are more source files and more include  depen-
    dencies to check.

    The  build  works out what to build from the source files of
    the project.  The _c_o_o_k(1) programs asks Aegis for a list  of
    files,  and then generates a list of output files from that.
    In this way, there is no need to add a new file to a list in
    a _M_a_k_e_f_i_l_e of some sort.

    33..22..  FFiillee TTeemmppllaatteess

    To  add a new page to the Web, a user initiates a Web change
    and then creates a new file via Aegis.  The new file will be
    created  according  to a pre-configured file template.  This
    will give them the common headers and footers automatically,
    all that is required is to fill in the text in the middle.

    So  that the page may be accessed, it will also be necessary
    to copy some other file,  again  via  Aegis,  and  embed  an
    anchor to the new page in the copied page.

    Files  are  copied and created via Aegis so that Aegis knows
    which files to transfer from your working directory into the
    baseline.   If you don't tell Aegis, they will not be built,
    and later they will not reach the baseline.

    33..33..  PPrreevviieeww aanndd RReevviieeww

    Once your Web pages build successfully, it  is  possible  to
    see  what the public will see - to preview them.  We do this
    by running a specialized web server  that  ``overlays''  the
    files  in your development directory over those in the base-
    line.  Essentially, this is a simple search path.  The  spe-
    cialized  web  server tell you a URL to open to preview your
    changes, and it will exist until you interrupt  it,  usually
    with Control-C.

    Reviewers  may use the same technique to look at an author's
    change, however reviewers are also encouraged to look at the
    HTML itself.




    Peter Miller                                          Page 7





    AUUG'96                Aegis is Only For Software, Isn't It?


    Using  this  specialized  web  server, it can be established
    exactly what the public will  see  when  the  pages  finally
    arrive in the Web baseline.  All of the Web pages are avail-
    able in this way, as the change's pages are seamlessly inte-
    grated  with  the  baseline  pages.  In this way, it is only
    necessary to copy the pages you actually need to edit.   All
    other pages are obtained from the baseline.  This often rep-
    resents a large saving in working disk storage.

    We have a set  of  layout  guidelines  which  are  available
    internally for our Web developers to read.  Reviewers (theo-
    retically) review against these guidelines,  and  developers
    are encouraged to have a quick look at the guidelines before
    completing the development of their changes.

    33..44..  IInntteeggrraattiioonn

    The integration stage is not particularly different from the
    integration  stage  for DNS.  However, some of the more time
    consuming tasks, which are not of great interest to develop-
    ers are done at this time: mostly generating or updating the
    various indexes for our Web as  required  for  the  specific
    change.

    33..55..  CCoonnccuurrrreenntt DDeevveellooppmmeenntt

    Performing  file  copies  via Aegis allows Aegis to note the
    version of the file at the time it was added to the  change.
    This  version  information is used later to detect file con-
    flicts, and to merge file contents.

    The chances of having Web pages in common  are  fairly  low,
    however  it  happens  fairly regularly.  The use of separate
    development directories means that this can be ignore for as
    long  as  the  author wants to.  When it is time to complete
    development of a Web change, the versions of the  files  are
    checked by Aegis.  If any are out-of-date, a 3-way merge may
    be performed to merge the  Web  baseline  updates  with  the
    edits in the change.

    33..66..  RReessuullttss

    The  AGSO  Web is intended to be a ``publication on demand''
    medium.  As a result, any data the public can see  needs  to
    be of publication quality already.  It is then only required
    for  the  client  to  print  interesting  material  one  the
    client's  printer.   While  the  HTML formatting may leave a
    little to be desired at present, we believe that the process
    we  employ is more than capable of delivering the quality of
    content that we desire.







    Peter Miller                                          Page 8





    AUUG'96                Aegis is Only For Software, Isn't It?


    44..  SSuummmmaarryy

    Many of the processes we perform on computers involve manip-
    ulating  and  assembling files in some way, many can be man-
    aged using SCM techniques.  Even where significant manipula-
    tion  (e.g.  compiling  software) is not required, automated
    input validation helps reduce the number of avoidable errors
    (much as compilers validate against input language).

    The  other  advantage  conferred by Aegis is that privileged
    operations are recorded, and are available for auditing pur-
    poses.  The privilege is controlled by access control lists,
    and requires active conspiracy by more than  one  person  to
    subvert.   Even  then, the audit record is inaccessible.  By
    using Aegis' notification facilities, it  is  even  possible
    for  highly  privileged system tables to be updated, and yet
    _r_o_o_t passwords need not be disclosed.

    The use of Aegis to assist in the management and  availabil-
    ity  of  critical  system services has been very successful,
    and will be used again.

    The use of Aegis to ensure that our Web is of  high  quality
    has been equally successful, and is a model we would happily
    recommend.

    55..  RReeffeerreenncceess


    +o    Miller, P. A., _`_`_A_e_g_i_s  _I_s  _O_n_l_y  _F_o_r  _S_o_f_t_w_a_r_e_,  _I_s_n_'_t
         _I_t_?_,_'_' AUUG '96 ACT Summer Conference Papers, 1996.

    [1]  Miller, P. A., _`_`_A_e_g_i_s _- _A _P_r_o_j_e_c_t _C_h_a_n_g_e _S_u_p_e_r_v_i_s_o_r_,_'_'
         AUUG '93 Conference Papers, 1993, p. 169-178.

    [2]  Miller,   P.    A.,    _A_e_g_i_s    _U_s_e_r    _G_u_i_d_e    http:-
         //www.canb.auug.org.au/~millerp/aegis.html,

    [3]  Mockapetris,  P., _`_`_D_o_m_a_i_n _N_a_m_e_s _- _C_o_n_c_e_p_t_s _a_n_d _F_a_c_i_l_i_-
         _t_i_e_s_'_'_, STD  13,  RFC  1034,  USC/Information  Sciences
         Institute, November 1987.

    [4]  Mockapetris,  P.,  _`_`_D_o_m_a_i_n  _N_a_m_e_s _- _I_m_p_l_e_m_e_n_t_a_t_i_o_n _a_n_d
         _S_p_e_c_i_f_i_c_a_t_i_o_n_'_'_, _S_T_D _1_3_, _R_F_C _1_0_3_5_, _U_S_C_/_I_n_f_o_r_m_a_t_i_o_n _S_c_i_-
         _e_n_c_e_s _I_n_s_t_i_t_u_t_e_, _N_o_v_e_m_b_e_r _1_9_8_7_.












    Peter Miller                                          Page 9





    AUUG'96                Aegis is Only For Software, Isn't It?





               Aegis is Only for Software, _I_s_n_'_t _I_t_?









                            Peter Miller

                      millerp@canb.auug.org.au









    +o Aegis at a Glance



    +o Managing DNS with Aegis



    +o Managing WWW with Aegis

























    Peter Miller                                         Page 10





    AUUG'96                Aegis is Only For Software, Isn't It?



                         Aegis at a Glance








    +o Software Configuration Management

           Manifest control, Version control, Build control,

           Change control, Quality control.



    +o Software development analogue


    

         Source                Chew              Finished
                    ------               ------
          Files              on them              Product





    +o Aegis provides change process and change environment

























    Peter Miller                                         Page 11





    AUUG'96                Aegis is Only For Software, Isn't It?



                   The Process in Too Much Detail

                   |
         new       |new
       change      |change
        undo       |
               awaiting
             development
                   |
       develop     |develop
       begin       |begin
       undo        |


                being                              Author
              developed

                   |                                  |
          develop  |devreelvoipew                          |
          end      |end fail                          |
          undo     |                                  |
     develop    being
     end       reviewed integrate                 Reviewer
     undo          |         fail                     |
                   |revrieevwiew                          |
                   |passpass                          |
                   |    undo                          |
               awaiting                               |
             integration                              |
                   |                                  |
       integrate   |integrate                         |
       begin       |begin                             |
       undo        |                                  |
                being
              integrated                           Editor
                   |
                   |integrate
                   |pass
                   |

              completed













    Peter Miller                                         Page 12





    AUUG'96                Aegis is Only For Software, Isn't It?





                     Advantages of the Process








    +o Access control lists



    +o Insulated development areas



    +o ``Backing Out'' is Easy



    +o All state transitions recorded



    +o State transition notification






























    Peter Miller                                         Page 13





    AUUG'96                Aegis is Only For Software, Isn't It?



                      Managing DNS with Aegis








    +o Users logged in as themselves (ACL)



    +o No _r_o_o_t access required



    +o Fully audited and reportable



    +o Notified of all changes



    +o Coordinates multiple system admininstrators






























    Peter Miller                                         Page 14





    AUUG'96                Aegis is Only For Software, Isn't It?



                         The DNS Build Step











    

                              Forward

                             map files

                                 |
                                 |
                                 |
                                 |
                               Chew

                              on them

                                 |
                                 |
                                 |
                                 |

                              Reverse
           _/_e_t_c_/_h_o_s_t_s                       _/_e_t_c_/_n_e_t_g_r_o_u_p
                             map files





















    Peter Miller                                         Page 15





    AUUG'96                Aegis is Only For Software, Isn't It?




                      The DNS Integration Step





    




                           baseline






                  development     development
                   directory       directory






                          integrator  integrate
                                           pass
                               |
                     integrate |
                         begin |
                               |

                          integration
                           directory





















    Peter Miller                                         Page 16





    AUUG'96                Aegis is Only For Software, Isn't It?


    +o Conflicts detected and managed



    +o This is when history is updated



    +o No _r_o_o_t access required for _n_a_m_e_d notification
















































    Peter Miller                                         Page 17





    AUUG'96                Aegis is Only For Software, Isn't It?



                      Managing WWW with Aegis








    +o Users logged in as themselves (ACL)



    +o Fully audited and reportable



    +o Notified of all changes



    +o Coordinates multiple authors



    +o Peer review is well understood






























    Peter Miller                                         Page 18





    AUUG'96                Aegis is Only For Software, Isn't It?



                         The WWW Build Step







    

                            Development

                             Directory




                                chew
              _m_a_s_t_e_r_/       -------------     _e_x_p_o_r_t_/
                              on them






    +o Server-side includes are resolved



    +o Include dependencies automatic



    +o HTML is checked against DTD



    +o Reports generated, e.g.  _W_h_a_t_'_s _N_e_w



    +o SQR compiled, _e_t_c_, _e_t_c













    Peter Miller                                         Page 19





    AUUG'96                Aegis is Only For Software, Isn't It?



                         Directory Stacking







         +                       +
        ++                      ++
       ++        _B_a_s_e_l_i_n_e       +
       +                       +
      +          TOC.html     ++
     ++                       +               _C_o_m_b_i_n_e_d _V_i_e_w
     +           ch1.html    +
    +                       +                    TOC.html

        _D_e_v_e_l_o_p_m_e_n_t _D_i_r_.         +               ch1.html
                                ++
            TOC.html            +                ch2.html
                               +
                              ++
                              +
            ch2.html         +
                            +





    +o Only files being edited or created are in development


      directory.



    +o Build tool must be able to cope with directory stack.



    +o ``Test Server'' must be able to stack, too, so can


      preview.











    Peter Miller                                         Page 20





    AUUG'96                Aegis is Only For Software, Isn't It?



                      The WWW Integration Step








    +o Integration build also constructs the indexes and other


      files not normally interesting to developers.



    +o Same picture as before, integration directory renamed to


      be the baseline.



    +o Conflicts are detected and managed.



    +o This is when history is updated.



    +o Server is sufficiently lightly loaded to run from _i_n_e_t_d,


      so no notification required.





















    Peter Miller                                         Page 21





    AUUG'96                Aegis is Only For Software, Isn't It?



                  Aegis is Only for Software, _N_o_t_!








    +o Access control lists, no _r_o_o_t required



    +o Audit trail, statistics and reports



    +o Quality control for Publication on Demand



    +o Quality control for critical systems


































    Peter Miller                                         Page 22
