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       slapd-ndb - MySQL NDB backend to slapd




       The  ndb  backend  to  slapd(8) uses the MySQL Cluster package to store
       data, through its NDB API.  It provides fault  tolerance  with  extreme
       scalability, along with a degree of SQL compatibility.

       This  backend  is  designed to store LDAP information using tables that
       are also visible from SQL. It uses a higher level SQL API for  creating
       these  tables,  while  using  the  low  level  NDB  API for storing and
       retrieving the data within these tables. The NDB Cluster engine  allows
       data  to  be  partitioned  across multiple data nodes, and this backend
       allows multiple slapd instances to operate  against  a  given  database

       The  general  approach  is  to use distinct tables for each LDAP object
       class.  Entries comprised of multiple object classes  will  have  their
       data  spread  across  multiple  tables.  The  data  tables use a 64 bit
       entryID as their primary key. The DIT  hierarchy  is  maintained  in  a
       separate table, which maps DNs to entryIDs.

       This  backend  is  experimental. While intended to be a general-purpose
       backend, it is currently missing a number of common LDAP features.  See
       the TODO file in the source directory for details.


       These  slapd.conf  options apply to the ndb backend database.  That is,
       they must follow a "database ndb" line and come before  any  subsequent
       "backend" or "database" lines.  Other database options are described in
       the slapd.conf(5) manual page.


       dbhost <hostname>
              The name or IP address of the host running the MySQL server. The
              default  is  "localhost".  On  Unix systems, the connection to a
              local server is made using a Unix Domain socket, whose  path  is
              specified using the dbsocket directive.

       dbuser <username>
              The  MySQL  login ID to use when connecting to the MySQL server.
              The chosen user must have sufficient  privileges  to  manipulate
              the SQL tables in the target database.

       dbpasswd <password>
              The password for the dbuser.

       dbname <database name>
              The name of the MySQL database to use.

       dbport <port>
              The  port  number  to  use  for  the TCP connection to the MySQL

       dbsocket <path>
              The socket to be used for connecting to a local MySQL server.

       dbflag <integer>
              Client flags for the MySQL session. See the MySQL  documentation
              for details.

       dbconnect <connectstring>
              The  name or IP address of the host running the cluster manager.
              The default is "localhost".

       dbconnections <integer>
              The number of cluster connections to establish. Using  up  to  4
              may improve performance under heavier load. The default is 1.


       attrlen <attribute> <length>
              Specify  the  column  length  to use for a particular attribute.
              LDAP attributes are stored in  individual  columns  of  the  SQL
              tables.  The  maximum  column  lengths  for  each column must be
              specified when creating these tables. If a length constraint was
              specified  in the attribute's LDAP schema definition, that value
              will be  used  by  default.  If  the  schema  didn't  specify  a
              constraint,  the default is 128 bytes.  Currently the maximum is

       index <attr[,attr...]>
              Specify a list  of  attributes  for  which  indexing  should  be
              maintained.    Currently  there  is  no  support  for  substring
              indexing; a single index structure provides presence,  equality,
              and inequality indexing for the specified attributes.

       attrset <set> <attrs>
              Specify  a list of attributes to be treated as an attribute set.
              This directive creates a table named set which will contain  all
              of  the listed attributes.  Ordinarily an attribute resides in a
              table named by an object class that uses the attribute. However,
              attributes  are  only  allowed to appear in a single table.  For
              attributes that are  derived  from  an  inherited  object  class
              definition,  the  attribute  will only be stored in the superior
              class's  table.   Attribute  sets  should  be  defined  for  any
              attributes  that  are used in multiple unrelated object classes,
              i.e., classes that are not connected  by  a  simple  inheritance


       The  ndb  backend  honors most access control semantics as indicated in


              default slapd configuration file


       slapd.conf(5),  slapd-config(5),  slapd(8),   slapadd(8),   slapcat(8),
       slapindex(8), MySQL Cluster documentation.


       Howard Chu, with assistance from Johan Andersson et al @ MySQL.