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  lbcd provides a lightweight way to query a system via unauthenticated
  UDP for system load information plus some related information that may
  be relevant to determining which system to hand out.  It was designed
  for use with the lbnamed DNS load balancer [1].  System load, number of
  logged-in users, free /tmp space, and system uptime are always returned.
  lbcd can also be configured to probe various local services and modify
  the returned weights based on whether those services are reachable, or
  to return a static weight for round-robin load balancing.

  [1] https://www.stanford.edu/~riepel/lbnamed/

  The information provided isn't particularly sophisticated, and a good
  hardware load balancer will be able to consider such things as
  connection latency and responsiveness to make better decisions.
  However, lbcd with lbnamed works quite well for smaller scale problems,
  scales well to multiple load balance pools for different services,
  provides a simple UDP health check service, and is much simpler and
  cheaper to understand and deploy.

  Included in this package is a small client program, lbcdclient, which
  can query an lbcd server and display a formatted version of the returned
  information.

  It was originally written by Roland Schemers.  Larry Schwimmer rewrote
  it to add protocol version 3 with some additional features and service
  probing, and then I rewrote it again to update the coding style and use
  my standard portability layer.

REQUIREMENTS

  lbcd is written in C, so you'll need a C compiler.  It also uses kernel
  calls to obtain load and uptime information, and at present has only
  been ported to Linux, Solaris, AIX, various BSD systems, Mac OS X,
  HP-UX, IRIX, and Tru64.  It is currently primarily tested on Linux.
  Platforms not listed may require some porting effort, as may old or
  unusual platforms that aren't regularly tested.

  The lbcdclient program requires Perl 5.6 or later and requires the
  IO::Socket::INET6 module for IPv6 support.

  To bootstrap from a Git checkout, or if you change the Automake files
  and need to regenerate Makefile.in, you will need Automake 1.11 or
  later.  For bootstrap or if you change configure.ac or any of the m4
  files it includes and need to regenerate configure or config.h.in, you
  will need Autoconf 2.64 or later.

BUILDING AND INSTALLATION

  You can build and install lbcd with the standard commands:

      ./configure
      make
      make install

  If you are building from a Git clone, first run ./bootstrap in the
  source directory to generate the build files.  make install will
  probably have to be done as root.  Building outside of the source
  directory is also supported, if you wish, by creating an empty directory
  and then running configure with the correct relative path.

  lbcd looks for $sysconfdir/nolbcd and returns the maximum load if that
  file is present, allowing one to effectively drop a system out of a
  load-balanced pool by touching that file.  By default, the path is
  /usr/local/etc/nolbcd, but you may want to pass --sysconfdir=/etc to
  configure to use /etc/nolbcd.

  lbcdclient is written in Perl, so you may have to edit the first line of
  the script to point to the correct Perl location on your system.  It
  does not use any sophisticated Perl features or add-on modules.

  Pass --enable-silent-rules to configure for a quieter build (similar to
  the Linux kernel).  Use make warnings instead of make to build with full
  compiler warnings (requires either GCC or Clang and may require a
  relatively current version of the compiler).

  You will generally want to start lbcd at system boot.  All that is
  needed is a simple init script to start lbcd with the appropriate
  options or kill it again.  It writes its PID into /var/run/lbcd.pid by
  default (and this can be changed with the -P option).  On many systems,
  lbcd will need to run as root or as a member of particular groups to
  obtain system load average and uptime information.

TESTING

  lbcd comes with a test suite, which you can run after building with:

      make check

  If a test fails, you can run a single test with verbose output via:

      tests/runtests -o <name-of-test>

  Do this instead of running the test program directly since it will
  ensure that necessary environment variables are set up.

  Currently, the test suite only checks the portability and utility
  libraries, not the functionality of lbcd or lbcdclient.

  To enable tests that don't detect functionality problems but are used to
  sanity-check the release, set the environment variable RELEASE_TESTING
  to a true value.  To enable tests that may be sensitive to the local
  environment or that produce a lot of false positives without uncovering
  many problems, set the environment variable AUTHOR_TESTING to a true
  value.

SUPPORT

  This package is not currently maintained and will not get further
  releases or bug fixes.  I do not recommend using it unless you're
  willing to take over maintenance.

  The lbcd web page at:

      https://www.eyrie.org/~eagle/software/lbcd/

  has the last released version, its documentation, and pointers to any
  additional resources.

SOURCE REPOSITORY

  lbcd was maintained using Git.  You can access the current source on