Comment 6 for bug 1557640

Reviewed: https://review.openstack.org/295932
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=d774e70d6bd511ab52e387493f1fb18ae4975565
Submitter: Jenkins
Branch: stable/liberty

commit d774e70d6bd511ab52e387493f1fb18ae4975565
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.

    Conflicts:
     neutron/agent/linux/dhcp.py

    Change-Id: Ie176ef123c194c22dca0967a6acfb9a48c959e6c
    Depends-On: I4041478ca09bd124827782774b8520908ef07be0
    Closes-Bug: 1557640
    (cherry picked from commit ed7411fa1c4d6a26cea3a8737b3c29ce6ff64363)