Comment 13 for bug 1459772

Reviewed: https://review.openstack.org/186815
Committed: https://git.openstack.org/cgit/stackforge/fuel-library/commit/?id=42df864217042cd2be03fde25ba6c235835d4835
Submitter: Jenkins
Branch: master

commit 42df864217042cd2be03fde25ba6c235835d4835
Author: Vladimir Kuklin <email address hidden>
Date: Mon Jun 1 17:57:41 2015 +0300

    Make HAProxy check of swift proxy backends via management VIP

    W/o this fix, when the management interface on the controller node
    running a Swift proxy is down, HAProxy would fail to update
    its backend status at the storage network.

    This is a problem as we want swift backends not able to connect the
    swift endpoint via the management VIP to be marked down. Othewise,
    responces time for any requested swift commands would be drastically
    longer. Simple httpcheck option cannot resolve this because the swift
    healthcheck reports OK, if conntacted via the storage network.

    In order to fix this, simple healthcheck script is implemented.
    This script is running as HTTP xinetid service at TCP port 49001 and
    is accessible only from the localhost, 240.0.0.2, and storage plus
    management networks. The service verifies the node under check for the:
    a) management VIP is pingable via ICMP (by 3 packets)
    b) Swift endpoint is reachable by TCP-connect via the local storage address
    within 5 seconds connection timeout
    c) Swift healthcheck report via the local storage address endpoint is OK

    Reports an HTTP 200 OK, if all of the results are OK.
    Otherwise, it would report an HTTP 503 Error.
    Expected Swift node control plane failover time will be around 30 seconds.
    Swift data plane is not affected.

    DocImpact: Reference architecture, swift failover.

    Closes-bug: #1459772
    Related-bug: #1460623

    Change-Id: I55a35b45257763a20f33bd47cb5c57de53558ccf
    Signed-off-by: Bogdan Dobrelya <email address hidden>