Comment 7 for bug 1557640

Reviewed: https://review.openstack.org/296352
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=bd3e9c3b1e759d4296cdb9a816a63ef773ea5f63
Submitter: Jenkins
Branch: stable/mitaka

commit bd3e9c3b1e759d4296cdb9a816a63ef773ea5f63
Author: Stephen Eilert <email address hidden>
Date: Tue Mar 15 13:54:23 2016 -0700

    Removes host file contents from DHCP agent logs

    The change I3ad7864eeb2f959549ed356a1e34fa18804395cc addressed a
    performance impact by removing logging calls from inside the loop that
    creates the hosts file in memory. However, it also introduced the
    dumping of said hosts file to the logs.

    On deployments with a very high number of ports(>5K), this increases the
    load of the node substantially. The problem is worse when a high number
    of port updates is received in a short amount of time.

    There is also the administrative burden caused by the sheer amount of
    data being logged.

    If the content of the host file is required for debugging purposes, it
    can be found at /opt/stack/data/neutron/dhcp/<net-id>/host

    This patch is trivial and only removes the logging of the file contents.
    The 'building'/'done building' logging calls may still provide useful
    information.

    Change-Id: Ie176ef123c194c22dca0967a6acfb9a48c959e6c
    Closes-Bug: 1557640
    (cherry picked from commit ed7411fa1c4d6a26cea3a8737b3c29ce6ff64363)