Diff for /admin/appendix-changes.sdf between versions 1.1 and 1.8.2.2

version 1.1, 2007/08/24 21:24:34 version 1.8.2.2, 2007/10/23 19:06:09
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 # $OpenLDAP: pkg/openldap-guide/admin/appendix-configs.sdf,v 1.2 2007/06/01 19:56:17 ghenry Exp $  # $OpenLDAP: pkg/openldap-guide/admin/appendix-changes.sdf,v 1.10 2007/10/14 21:38:46 ghenry Exp $
 # Copyright 2007 The OpenLDAP Foundation, All Rights Reserved.  # Copyright 2007 The OpenLDAP Foundation, All Rights Reserved.
 # COPYING RESTRICTIONS APPLY, see COPYRIGHT.  # COPYING RESTRICTIONS APPLY, see COPYRIGHT.
   
 H1: Changes Since Previous Release  H1: Changes Since Previous Release
   
 Nice intro here to praise everyones hard work!  The following sections attempt to summarize the new features and changes in OpenLDAP
   software since the 2.3.x release and the OpenLDAP Admin Guide.
   
 H2: New Guide Sections  H2: New Guide Sections
   
 * Overlays  In order to make the Admin Guide more thorough and cover the majority of questions
 * Backends  asked on the OpenLDAP mailing lists and scenarios discussed there, we have added the following new sections:
 * Tuning  
 * complete later.........  
   
 H2: New Features in 2.4  * {{SECT:When should I use LDAP?}}
   * {{SECT:When should I not use LDAP?}}
   * {{SECT:LDAP vs RDBMS}}
   * {{SECT:Backends}}
   * {{SECT:Overlays}}
   * {{SECT:Replication}}
   * {{SECT:Maintenance}}
   * {{SECT:Monitoring}}
   * {{SECT:Tuning}}
   * {{SECT:Troubleshooting}}
   * {{SECT:Changes Since Previous Release}}
   * {{SECT:Upgrading from 2.3.x}}
   * {{SECT:Common errors encountered when using OpenLDAP Software}}
   * {{SECT:Recommended OpenLDAP Software Dependency Versions}}
   * {{SECT:Real World OpenLDAP Deployments and Examples}}
   * {{SECT:OpenLDAP Software Contributions}}
   * {{SECT:Configuration File Examples}}
   * {{SECT:LDAP Result Codes}}
   * {{SECT:Glossary}}
   
   Also, the table of contents is now 3 levels deep to ease navigation.
   
   
   H2: New Features and Enhancements in 2.4
   
   H3: Better {{B:cn=config}} functionality
   
   There is a new slapd-config(5) manpage for the {{B:cn=config}} backend. The 
   original design called for auto-renaming of config entries when you insert or 
   delete entries with ordered names, but that was not implemented in 2.3. It is 
   now in 2.4. This means, e.g., if you have
   
   >   olcDatabase={1}bdb,cn=config
   >   olcSuffix: dc=example,dc=com
   
   and you want to add a new subordinate, now you can ldapadd:
   
   >   olcDatabase={1}bdb,cn=config
   >   olcSuffix: dc=foo,dc=example,dc=com
   
   This will insert a new BDB database in slot 1 and bump all following databases
    down one, so the original BDB database will now be named:
   
   >   olcDatabase={2}bdb,cn=config
   >   olcSuffix: dc=example,dc=com
   
   H3: Better {{B:cn=schema}} functionality
   
   In 2.3 you were only able to add new schema elements, not delete or modify 
   existing elements. In 2.4 you can modify schema at will. (Except for the 
   hardcoded system schema, of course.)
   
   H3: More sophisticated Syncrepl configurations
   
   The original implementation of Syncrepl in OpenLDAP 2.2 was intended to support 
   multiple consumers within the same database, but that feature never worked and 
   was removed from OpenLDAP 2.3; you could only configure a single consumer in 
   any database.
   
   In 2.4 you can configure multiple consumers in a single database. The configuration 
   possibilities here are quite complex and numerous. You can configure consumers 
   over arbitrary subtrees of a database (disjoint or overlapping). Any portion 
   of the database may in turn be provided to other consumers using the Syncprov 
   overlay. The Syncprov overlay works with any number of consumers over a single 
   database or over arbitrarily many glued databases.
   
   H3: N-Way Multimaster Replication
   
   As a consequence of the work to support multiple consumer contexts, the syncrepl 
   system now supports full N-Way multimaster replication with entry-level conflict 
   resolution. There are some important constraints, of course: In order to maintain 
   consistent results across all servers, you must maintain tightly synchronized 
   clocks across all participating servers (e.g., you must use NTP on all servers). 
   
   The entryCSNs used for replication now record timestamps with microsecond resolution, 
   instead of just seconds. The delta-syncrepl code has not been updated to support 
   multimaster usage yet, that will come later in the 2.4 cycle.
   
   H3: Replicating {{slapd}} Configuration (syncrepl and {{B:cn=config}})
   
   Syncrepl was explicitly disabled on cn=config in 2.3. It is now fully supported 
   in 2.4; you can use syncrepl to replicate an entire server configuration from 
   one server to arbitrarily many other servers. It's possible to clone an entire 
   running slapd using just a small (less than 10 lines) seed configuration, or 
   you can just replicate the schema subtrees, etc. Tests 049 and 050 in the test 
   suite provide working examples of these capabilities.
   
   
   H3: Push-Mode Replication
   
   In 2.3 you could configure syncrepl as a full push-mode replicator by using it 
   in conjunction with a back-ldap pointed at the target server. But because the 
   back-ldap database needs to have a suffix corresponding to the target's suffix, 
   you could only configure one instance per slapd.
   
   In 2.4 you can define a database to be "hidden", which means that its suffix is 
   ignored when checking for name collisions, and the database will never be used 
   to answer requests received by the frontend. Using this "hidden" database feature 
   allows you to configure multiple databases with the same suffix, allowing you to 
   set up multiple back-ldap instances for pushing replication of a single database 
   to multiple targets. There may be other uses for hidden databases as well (e.g., 
   using a syncrepl consumer to maintain a *local* mirror of a database on a separate filesystem).
   
   
   H3: More extensive TLS configuration control
   
   In 2.3, the TLS configuration in slapd was only used by the slapd listeners. For 
   outbound connections used by e.g. back-ldap or syncrepl their TLS parameters came 
   from the system's ldap.conf file.
   
   In 2.4 all of these sessions inherit their settings from the main slapd configuration, 
   but settings can be individually overridden on a per-config-item basis. This is 
   particularly helpful if you use certificate-based authentication and need to use a 
   different client certificate for different destinations.
   
   
   H3: Performance enhancements
   
   Too many to list. Some notable changes - ldapadd used to be a couple of orders 
   of magnitude slower than "slapadd -q". It's now at worst only about half the 
   speed of slapadd -q. Some comparisons of all the 2.x OpenLDAP releases are available 
   at {{URL:http://www.openldap.org/pub/hyc/scale2007.pdf}}
   
   That compared 2.0.27, 2.1.30, 2.2.30, 2.3.33, and HEAD). Toward the latter end 
   of the "Cached Search Performance" chart it gets hard to see the difference 
   because the run times are so small, but the new code is about 25% faster than 2.3, 
   which was about 20% faster than 2.2, which was about 100% faster than 2.1, which 
   was about 100% faster than 2.0, in that particular search scenario. That test 
   basically searched a 1.3GB DB of 380836 entries (all in the slapd entry cache) 
   in under 1 second. i.e., on a 2.4GHz CPU with DDR400 ECC/Registered RAM we can 
   search over 500 thousand entries per second. The search was on an unindexed 
   attribute using a filter that would not match any entry, forcing slapd to examine 
   every entry in the DB, testing the filter for a match.
   
   Essentially the slapd entry cache in back-bdb/back-hdb is so efficient the search 
   processing time is almost invisible; the runtime is limited only by the memory 
   bandwidth of the machine. (The search data rate corresponds to about 3.5GB/sec; 
   the memory bandwidth on the machine is only about 4GB/sec due to ECC and register latency.)
   
 Another nice intro here  H3: New overlays
   
 H3: More overlays  
   
   * slapo-constraint (Attribute value constraints)
 * slapo-dds (Dynamic Directory Services, RFC 2589)  * slapo-dds (Dynamic Directory Services, RFC 2589)
 * slapo-memberof (reverse group membership maintenance)  * slapo-memberof (reverse group membership maintenance)
   
 H3: New features in existing ones  H3: New features in existing Overlays
   
   * slapo-pcache
     - Inspection/Maintenance 
       -- the cache database can be directly accessed via
          LDAP by adding a specific control to each LDAP request; a specific
          extended operation allows to consistently remove cached entries and entire
          cached queries
     - Hot Restart
       -- cached queries are saved on disk at shutdown, and reloaded if
         not expired yet at subsequent restart
   
 * slapo-pcache allows cache inspection/maintenance/hot restart  
 * slapo-rwm can safely interoperate with other overlays  * slapo-rwm can safely interoperate with other overlays
 * Dyngroup/Dynlist merge, plus security enhancements  * Dyngroup/Dynlist merge, plus security enhancements
     - added dgIdentity support (draft-haripriya-dynamicgroup)
   
 H3: New features in slapd  H3: New features in slapd
   
Line 38  H3: New features in libldap Line 183  H3: New features in libldap
   
 * ldap_sync client API (LDAP Content Sync Operation, RFC 4533)  * ldap_sync client API (LDAP Content Sync Operation, RFC 4533)
   
 H3: New clients and tools  H3: New clients, tools and tool enhancements
   
 * ldapexop for arbitrary extended operations  * ldapexop for arbitrary extended operations
 * complete support of controls in request/response for all clients  * Complete support of controls in request/response for all clients
   * LDAP Client tools now honor SRV records 
   
 H3: New build options  H3: New build options
   
 * Support for building against GnuTLS  * Support for building against GnuTLS
 * Advertisement of LDAP server in DNS  
   
   
 H2: Obsolete Features in 2.4  H2: Obsolete Features Removed From 2.4
   
   These features were strongly deprecated in 2.3 and removed in 2.4.
   
 H3: Slurpd  H3: Slurpd
   
   Please read the {{SECT:Replication}} section as to why this is no longer in
   OpenLDAP
   
   H3: back-ldbm
   
   back-ldbm was both slow and unreliable. Its byzantine indexing code was
   prone to spontaneous corruption, as were the underlying database libraries
   that were commonly used (e.g. GDBM or NDBM). back-bdb and back-hdb are
   superior in every aspect, with simplified indexing to avoid index corruption,
   fine-grained locking for greater concurrency, hierarchical caching for
   greater performance, streamlined on-disk format for greater efficiency
   and portability, and full transaction support for greater reliability.

Removed from v.1.1  
changed lines
  Added in v.1.8.2.2


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