OpenAFS Master Repository branch, openafs-stable-1_8_x, updated. openafs-stable-1_8_0-56-geb607b6

Gerrit Code Review gerrit@openafs.org
Thu, 7 Jun 2018 20:35:27 -0400


The following commit has been merged in the openafs-stable-1_8_x branch:
commit eb607b67793c37f57490ece47f93c65383a2fdf5
Author: Marcio Barbosa <mbarbosa@sinenomine.net>
Date:   Tue May 15 17:10:45 2018 -0400

    ubik: clones should not request votes
    
    Clones should not be able to become the sync-site. To make it possible,
    regular sites do not vote for a site tagged as clone. In other words,
    the clones ask for votes but they cannot be the sync-site. Knowing that
    their requests for votes should be refused by the regular sites, they
    should never have enough votes to win the election.
    
    In addition to the unnecessary network traffic created by these
    unnecessary requests, this current approach can be problematic in some
    specific situations. As an example, consider the following scenario:
    
        The user wants to turn a regular site, called host1, into a clone.
        To do so, he runs the following commands on every single server:
    
        $ bos removehost -server <server> -host host1
        $ bos addhost -server <server> -host host1 -clone
    
    After that, he restarts the servers, one by one. Depending on the delay
    between the restarts, a clone can become the sync-site. This is possible
    because the clones request votes from the other sites. If enough regular
    sites are not aware (yet) that the request for vote came from a clone,
    the clone in question can get enough votes to win the election.
    
    To fix the problems mentioned above, do not request votes if you cannot
    be the sync-site.
    
    Reviewed-on: https://gerrit.openafs.org/12654
    Tested-by: BuildBot <buildbot@rampaginggeek.com>
    Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
    (cherry picked from commit 3cc22a442e1dad628f0b11a32c4037fc7174dde4)
    
    Change-Id: Ifa748546aec6928eb4ca988a036d0bf8fb70f6f8
    Reviewed-on: https://gerrit.openafs.org/13116
    Tested-by: BuildBot <buildbot@rampaginggeek.com>
    Reviewed-by: Marcio Brito Barbosa <mbarbosa@sinenomine.net>
    Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
    Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>

 src/ubik/vote.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

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