3. LOCKSS: Lots of Copies Keep Stuff Safe
Stanford Releases LOCKSS Project User Interface and Participant
Palo Alto, CA January 12, 2002. Stanford University Libraries has
released two new resources as part of its LOCKSS digital preservation
One of them is a demo of the user interface to be used by libraries
participating in the LOCKSS system. The other is an interactive
online world map showing the status of the 60 test caches at 46
worldwide. LOCKSS (Lots of Copies Keep Stuff Safe), provides a strategy
for long-term preservation by systematically caching content in
a self-correcting P2P network.
This project, midway through the beta testing of the LOCKSS software,
enables libraries to maintain high integrity persistent caches of
electronic journal content to which they have subscribed. Using
a decentralized, peer-to-peer network of like holdings at other
participating libraries, the LOCKSS system assures that libraries
can retain indefinite access to subscribed journal issues, even
if the publisher's online site goes down -even if the publisher
goes out of business. This addresses one of the fundamental barriers
to the acceptance of online journals on the part of libraries, namely,
the issue of assuring long-term access to content.
The demo of the user interface (available at http://lockss1.stanford.edu/uidemo/
) shows the administrative tools participating libraries will use
to control and monitor their local cache. Its features include:
- Journal Status, which reports the current condition of the
local copy of each cached journal and when it was last updated,
as well as the number of copies the installation can detect among
all the LOCKSS caches. If problems are detected, the local copy
will fix itself by comparing itself to other copies on the network.
No action is required.
- Journal Setup, which allows the library to determine often
the system crawls the publisher's web site for new content and
sets values for when to email the library's system administrator
about such things as insufficient other caches detected or that
it can no longer find the publisher's web site.
- Journal Access Control, which determines which IP address ranges
are authorized to use the local cache.
This user interface includes significant improvements over previous
versions and is the result of consulting with and feedback from
some of the early sites.
The world map (see http://sul-lockss18.stanford.edu:8080/GlobalCacheMonitor
) displays information about the success of packet data transmission,
by journal, for each participating beta test
library and relative "reputation" data (regarding the
integrity of previously transmitted data). The map may be viewed
at a global level or zoomed in to continent-wide. This tool applies
to the beta test network only, as in the eventual production system,
there will not be a central agent that "knows" every installation
of a journal cache; this is a critical security feature to prevent
tampering or censorship.
The current beta test configuration includes 60 caches at 46 libraries
and two scholarly journals. The system has been in continuous operation
for over six months. The fault-tolerance of the system has been
amply demonstrated: two beta caches suffered catastrophic disk failures.
Both were able to restart with new, empty disks and recover their
Numerous publishers have expressed strong support for the LOCKSS
project. They are particularly happy that the system shows the potential
to preserve digital materials now, with current publishing systems.
No new standards or infrastructure is required. The cost of entry
is low, the payoffs promise to be high.
For a list of beta test libraries and publishers endorsing the
LOCKSS project and caching solution, see http://lockss.stanford.edu/projectstatus.htm
The LOCKSS project is supported by grants from the Andrew W. Mellon
Foundation, the National Science Foundation, and Sun Microsystems,
Contact: Vicky Reich, (650) 725-1134, firstname.lastname@example.org