Note, tag 5.7.2.0 doesn't have this issue but the 5.7.z branch has 81ccccc3b77, which contains the commit that this BZ fixes.  I'm suggesting this be a blocker since the logging is excessive and we establish a DRb client each time we process a queue message.

New commit detected on ManageIQ/manageiq/euwe:
https://github.com/ManageIQ/manageiq/commit/0a1ad0e0a0d12c6662e420322cc92d2d4be83c82

commit 0a1ad0e0a0d12c6662e420322cc92d2d4be83c82
Author:     Gregg Tanzillo <gtanzill>
AuthorDate: Tue Apr 4 18:24:33 2017 -0400
Commit:     Satoe Imaishi <simaishi>
CommitDate: Thu Apr 6 12:35:12 2017 -0400

    Merge pull request #14638 from jrafanie/fix_worker_monitor_drb_new_client_each_time
    
    Make worker_monitor_drb act like a reader again!
    (cherry picked from commit 56ee45a63c780fff16722f91ba09d6acc0642ca0)
    
    https://bugzilla.redhat.com/show_bug.cgi?id=1439308

 app/models/miq_worker/runner.rb       | 29 +++++++++++++++--------------
 spec/models/miq_worker/runner_spec.rb |  8 ++++++++
 2 files changed, 23 insertions(+), 14 deletions(-)

Hi Joe, whats the best way to reproduce this one?

Thanks,
Luke

Verified in 5.7.2.1

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2017:0898