Description of problem:
A "Actions::Katello::ContentView::CapsuleGenerateAndSync" task fails in a "Actions::Pulp::Consumer::SyncCapsule" step on a Red Hat repository with error "PulpExecutionException: Importer indicated a failed response".

The details of the step show error "command document too large" reported for errata:

85: Actions::Pulp::Consumer::SyncCapsule (skipped) [ 2600.20s / 55.35s ]
Started at: 2017-07-20 12:09:03 UTC
Ended at: 2017-07-20 12:52:23 UTC
Real time: 2600.20s
Execution time (excluding suspended state): 55.35s

Input:

---
capsule_id: 8
repo_pulp_id: IAG-Library-HA_RHEL7_x86_64-Red_Hat_Software_Collections__for_RHEL_Server_-Red_Hat_Software_Collections_RPMs_for_Red_Hat_Enterprise_Linux_7_Server_x86_64_7Server
remote_user: admin
remote_cp_user: admin
locale: en

Output:

---
pulp_tasks:
- exception: 
  task_type: pulp.server.managers.repo.sync.sync
  _href: "/pulp/api/v2/tasks/caa86789-46a2-4c15-8755-1e3093fb6ac1/"
  task_id: caa86789-46a2-4c15-8755-1e3093fb6ac1
  tags:
  - pulp:repository:IAG-Library-HA_RHEL7_x86_64-Red_Hat_Software_Collections__for_RHEL_Server_-Red_Hat_Software_Collections_RPMs_for_Red_Hat_Enterprise_Linux_7_Server_x86_64_7Server
  - pulp:action:sync
  finish_time: '2017-07-20T12:21:27Z'
  _ns: task_status
  start_time: '2017-07-20T12:12:18Z'
  traceback: |
    Traceback (most recent call last):
      File "/usr/lib/python2.7/site-packages/celery/app/trace.py", line 240, in trace_task
        R = retval = fun(*args, **kwargs)
      File "/usr/lib/python2.7/site-packages/pulp/server/async/tasks.py", line 473, in __call__
        return super(Task, self).__call__(*args, **kwargs)
      File "/usr/lib/python2.7/site-packages/pulp/server/async/tasks.py", line 103, in __call__
        return super(PulpTask, self).__call__(*args, **kwargs)
      File "/usr/lib/python2.7/site-packages/celery/app/trace.py", line 437, in __protected_call__
        return self.run(*args, **kwargs)
      File "/usr/lib/python2.7/site-packages/pulp/server/controllers/repository.py", line 812, in sync
        raise pulp_exceptions.PulpExecutionException(_('Importer indicated a failed response'))
    PulpExecutionException: Importer indicated a failed response
    
  spawned_tasks: []
  progress_report:  
[...]
      errata:
        state: FAILED
        error: command document too large
[...]

This happens on all capsules.

Version-Release number of selected component (if applicable):
satellite-6.2.10-4.0.el7sat

How reproducible:
Always

Steps to Reproduce:
1. Unknown, couldn't reproduce this internally
2.
3.

Actual results:
Step "Actions::Pulp::Consumer::SyncCapsule" of the task is skipped.
The repository is missing in the Capsule.
Clients registered to the Capsule with the involved repository enabled can not yum install packages from the repository.

Expected results:
The step completes successfully and clients can install packages.

Additional info:
Error is similar to bug 1410649 (already fixed in 6.2.9), but here the problem happens on a Red Hat repository.