Comment 8 for bug 1789177

Reviewed: https://review.opendev.org/713153
Committed: https://git.openstack.org/cgit/openstack/oslo.messaging/commit/?id=b67a457e4fa71e9220c149087dce013c7f81144f
Submitter: Zuul
Branch: stable/rocky

commit b67a457e4fa71e9220c149087dce013c7f81144f
Author: Oleg Bondarev <email address hidden>
Date: Mon Aug 27 12:18:58 2018 +0400

    Use default exchange for direct messaging

    Lots of exchanges create problems during failover under high
    load. Please see bug report for details.

    This is step 1 in the process: only using default exchange
    when publishing. Consumers will still consume on separate
    exchanges (and on default exchange by default) so this
    should be (and tested to be) a non-breaking and
    upgrade-friendly change.

    Step 2 is to update consumers to only listen on default exchange,
    to happen in T release.

    Change-Id: Id3603f4b7e1274b616d76e1c0c009d2ab7f6efb6
    Closes-Bug: #1789177
    (cherry picked from commit 3a5de89dd686dbd9660f140fdddd9c78b20e1632)