README for bdii package
=======================


Function:
---------
The Berkeley Database Information Index (BDII) consists of two or more
standard LDAP databases that are populated by an update process.
Port forwarding is used to enable one or more databases to serve data
while one database is being refreshed.  The databases are refreshed
cyclically.  Any incoming connection is forwarded to the most recently
updated database, while old connections are allowed to linger until
it is the turn of their database to be refreshed and restarted.
The update process obtains LDIF from either doing an ldapsearch on LDAP
URLs or by running a local script (given by a URL with "file" protocol)
that generates LDIF.  The LDIF is then inserted into the LDAP database.
Options exist to update the list of LDAP URLs from a web page and
to use an LDIF file from a web page to modify the data before it is
inserted into the database.



Cache use:
----------
Whenever a remote server is contacted and the ldapsearch command times out
the update process tries to find an (old) cached entry in the var/cache/ 
directory. If no entry is found a message is printed to the logfile.

! Attention !
If the remote host cannot be contacted due to a connection problem
no cached entry is taken. No message is printed to the logfile.



Compressed Content Exchange Mechanism (CCEM):
---------------------------------------------
The Compressed Content Exchange Mechanism is intended to speed up the 
gathering of information in case of a ldapsearch to another BDII instance.
The update process first tries to find the entry containing the compressed 
content of the queried instance and subsequently adds the information to 
its upcoming database. If the CCEM fails the normal procedure as described 
in the previous paragraph is executed.
The CCEM function is enabled by default in version >= 3.9.1. To disable, 
add the following to your bdii.conf:
BDII_CCEM=no


BDII Status Information Mechanism (BSIM):
-----------------------------------------
The BDII Status Information Mechanism is intended to allow better monitoring 
possibilities, spotting of upraising problems and resulting failure prevention.
It adds status information about the BDII instance into the 'o=infosys' root 
containing metrics like the number of entries added in the last cyle, 
the time to do so, etc. 
The description of thoese metrics can be found in the etc/BDII.schema file.





History:

Original version David Groep, NIKHEF
22-01-2004 Restructured by Laurence Field
2005 Restructured by Maarten Litmaath
2008 Enhanced by Felix Ehm


License:

Build dependencies: None

Runtime dependencies: openldap

How to build and install: make install

How to configure: http://lfield.home.cern.ch/lfield/bdii/

More information: http://lfield.home.cern.ch/lfield/bdii/

Known bugs: http://lfield.home.cern.ch/lfield/bdii/
            https://savannah.cern.ch/projects/lcgoperation/

Planned evolution:


Contact: Laurence.Field@cern.ch, Maarten.Litmaath@cern.ch

