Description of problem:
----------------------
Individual bucket sync status is reporting completely synced but there are 2.3 million bilog keys generating large omap object warnings.



Component Version-Release:
-------------------------
7.6 (Maipo)   3.10.0-957.el7.x86_64
ceph-base.x86_64   2:12.2.8-128.el7cp



How reproducible:
----------------
unknown



Steps to Reproduce:
------------------
1. configure multisite on two clusters using ansible playbook
2. populate master site with data, observe sync activity
3. check bucket sync status and bilog details



Actual results:
--------------
bucket sync status reports complete but bilogs aren't trimmed accordingly



Expected results:
----------------
bucket sync status reports complete and bilogs are trimmed



Additional info:
---------------
# radosgw-admin bucket sync status --bucket=mycontainers2
          realm 25eeb4ef-aa47-4f50-85e3-0c9a68883cf1 (scaleLTA)
      zonegroup 053ddd45-7321-4a3f-b9b7-253edc830725 (cloud07)
           zone d6499579-6232-4209-b1e4-88112599b5ac (site2)
         bucket mycontainers2[7659bed4-dcd2-4616-95b3-4f7d971c6dd8.2887729.1]

    source zone 7659bed4-dcd2-4616-95b3-4f7d971c6dd8 (site1)
                full sync: 0/1 shards
                incremental sync: 1/1 shards
                bucket is caught up with source



# radosgw-admin bucket stats
   ...
    {
        "bucket": "mycontainers2",
        "zonegroup": "053ddd45-7321-4a3f-b9b7-253edc830725",
        "placement_rule": "default-placement",
        "explicit_placement": {
            "data_pool": "",
            "data_extra_pool": "",
            "index_pool": ""
        },
        "id": "7659bed4-dcd2-4616-95b3-4f7d971c6dd8.2887729.1",
        "marker": "7659bed4-dcd2-4616-95b3-4f7d971c6dd8.2887729.1",
        "index_type": "Normal",
        "owner": "johndoe",
        "ver": "0#2365894",
        "master_ver": "0#0",
        "mtime": "2019-08-13 23:47:21.536665",
        "max_marker": "0#00002365893.2366059.5",
        "usage": {
            "rgw.main": {
                "size": 11271073160000,
                "size_actual": 11271454883840,
                "size_utilized": 11271073160000,
                "size_kb": 11006907383,
                "size_kb_actual": 11007280160,
                "size_kb_utilized": 11006907383,
                "num_objects": 210972
            }
        },
        "bucket_quota": {
            "enabled": false,
            "check_on_raw": true,
            "max_size": -1,
            "max_size_kb": 0,
            "max_objects": -1
        }
    },

    ...



# rados -p site1.rgw.buckets.index listomapkeys .dir.7659bed4-dcd2-4616-95b3-4f7d971c6dd8.2887729.1 | wc -l
2346867




From the log ...
272:77fe05db:::.dir.7659bed4-dcd2-4616-95b3-4f7d971c6dd8.2907365.1:head Key count: 2342160 Size (bytes): 448597889