diff --git a/swh/storage/tests/test_retry.py b/swh/storage/tests/test_retry.py
--- a/swh/storage/tests/test_retry.py
+++ b/swh/storage/tests/test_retry.py
@@ -64,6 +64,9 @@
         # ok then!
         {'content:add': 1}
     ]
+    mock_sleep = mocker.patch(
+        'swh.storage.retry.RetryingProxyStorage'
+        '.content_add.retry.sleep')
 
     sample_content = sample_data['content'][0]
 
@@ -78,6 +81,7 @@
         call([Content.from_dict(sample_content)]),
         call([Content.from_dict(sample_content)]),
     ])
+    assert mock_sleep.call_count == 2
 
 
 def test_retrying_proxy_swh_storage_content_add_failure(
@@ -136,6 +140,9 @@
         # ok then!
         {'content:add': 1}
     ]
+    mock_sleep = mocker.patch(
+        'swh.storage.retry.RetryingProxyStorage'
+        '.content_add_metadata.retry.sleep')
 
     sample_content = sample_data['content_metadata'][0]
 
@@ -147,6 +154,7 @@
         call([Content.from_dict(sample_content)]),
         call([Content.from_dict(sample_content)]),
     ])
+    assert mock_sleep.call_count == 2
 
 
 def test_retrying_proxy_swh_storage_content_add_metadata_failure(
@@ -203,6 +211,9 @@
         # ok then!
         sample_origin['url']
     ]
+    mock_sleep = mocker.patch(
+        'swh.storage.retry.RetryingProxyStorage'
+        '.origin_add_one.retry.sleep')
 
     origin = swh_storage.origin_get(sample_origin)
     assert not origin
@@ -215,6 +226,7 @@
         call(Origin.from_dict(sample_origin)),
         call(Origin.from_dict(sample_origin)),
     ])
+    assert mock_sleep.call_count == 2
 
 
 def test_retrying_proxy_swh_storage_origin_add_one_failure(
@@ -278,6 +290,9 @@
         # ok then!
         {'origin': origin_url, 'visit': 1}
     ]
+    mock_sleep = mocker.patch(
+        'swh.storage.retry.RetryingProxyStorage'
+        '.origin_visit_add.retry.sleep')
 
     origin = list(swh_storage.origin_visit_get(origin_url))
     assert not origin
@@ -290,6 +305,7 @@
         call(sample_origin, '2020-01-01', 'git'),
         call(sample_origin, '2020-01-01', 'git')
     ])
+    assert mock_sleep.call_count == 2
 
 
 def test_retrying_proxy_swh_storage_origin_visit_add_failure(
@@ -351,6 +367,9 @@
         # ok then!
         [sample_tool]
     ]
+    mock_sleep = mocker.patch(
+        'swh.storage.retry.RetryingProxyStorage'
+        '.tool_add.retry.sleep')
 
     tool = swh_storage.tool_get(sample_tool)
     assert not tool
@@ -363,6 +382,7 @@
         call([sample_tool]),
         call([sample_tool]),
     ])
+    assert mock_sleep.call_count == 2
 
 
 def test_retrying_proxy_swh_storage_tool_add_failure(
@@ -434,6 +454,9 @@
         # ok then!
         'provider_id',
     ]
+    mock_sleep = mocker.patch(
+        'swh.storage.retry.RetryingProxyStorage'
+        '.metadata_provider_add.retry.sleep')
 
     provider = swh_storage.metadata_provider_get_by(provider_get)
     assert not provider
@@ -449,6 +472,7 @@
         call(*provider_args),
         call(*provider_args),
     ])
+    assert mock_sleep.call_count == 2
 
 
 def test_retrying_proxy_swh_storage_metadata_provider_add_failure(
@@ -518,6 +542,10 @@
         None
     ]
 
+    mock_sleep = mocker.patch(
+        'swh.storage.retry.RetryingProxyStorage'
+        '.origin_metadata_add.retry.sleep')
+
     url = origin['url']
     ts = ori_meta['discovery_date']
     tool_id = ori_meta['tool']
@@ -531,6 +559,7 @@
         call(url, ts, provider_id, tool_id, metadata),
         call(url, ts, provider_id, tool_id, metadata)
     ])
+    assert mock_sleep.call_count == 2
 
 
 def test_retrying_proxy_swh_storage_origin_metadata_add_failure(
@@ -607,6 +636,10 @@
         {'origin': origin_url, 'visit': 1}
     ]
 
+    mock_sleep = mocker.patch(
+        'swh.storage.retry.RetryingProxyStorage'
+        '.origin_visit_update.retry.sleep')
+
     visit_id = 1
     swh_storage.origin_visit_update(origin_url, visit_id, status='full')
 
@@ -618,6 +651,7 @@
         call(origin_url, visit_id, metadata=None,
              snapshot=None, status='full'),
     ])
+    assert mock_sleep.call_count == 2
 
 
 def test_retrying_proxy_swh_storage_origin_visit_update_failure(
@@ -671,6 +705,9 @@
         # ok then!
         {'directory:add': 1}
     ]
+    mock_sleep = mocker.patch(
+        'swh.storage.retry.RetryingProxyStorage'
+        '.directory_add.retry.sleep')
 
     sample_dir = sample_data['directory'][1]
 
@@ -687,6 +724,7 @@
         call([Directory.from_dict(sample_dir)]),
         call([Directory.from_dict(sample_dir)]),
     ])
+    assert mock_sleep.call_count == 2
 
 
 def test_retrying_proxy_swh_storage_directory_add_failure(
@@ -744,6 +782,10 @@
         {'revision:add': 1}
     ]
 
+    mock_sleep = mocker.patch(
+        'swh.storage.retry.RetryingProxyStorage'
+        '.revision_add.retry.sleep')
+
     sample_rev = sample_data['revision'][0]
 
     revision = next(swh_storage.revision_get([sample_rev['id']]))
@@ -759,6 +801,7 @@
         call([Revision.from_dict(sample_rev)]),
         call([Revision.from_dict(sample_rev)]),
     ])
+    assert mock_sleep.call_count == 2
 
 
 def test_retrying_proxy_swh_storage_revision_add_failure(
@@ -816,6 +859,10 @@
         {'release:add': 1}
     ]
 
+    mock_sleep = mocker.patch(
+        'swh.storage.retry.RetryingProxyStorage'
+        '.release_add.retry.sleep')
+
     sample_rel = sample_data['release'][0]
 
     release = next(swh_storage.release_get([sample_rel['id']]))
@@ -831,6 +878,7 @@
         call([Release.from_dict(sample_rel)]),
         call([Release.from_dict(sample_rel)]),
     ])
+    assert mock_sleep.call_count == 2
 
 
 def test_retrying_proxy_swh_storage_release_add_failure(
@@ -888,6 +936,10 @@
         {'snapshot:add': 1}
     ]
 
+    mock_sleep = mocker.patch(
+        'swh.storage.retry.RetryingProxyStorage'
+        '.snapshot_add.retry.sleep')
+
     sample_snap = sample_data['snapshot'][0]
 
     snapshot = swh_storage.snapshot_get(sample_snap['id'])
@@ -903,6 +955,7 @@
         call([Snapshot.from_dict(sample_snap)]),
         call([Snapshot.from_dict(sample_snap)]),
     ])
+    assert mock_sleep.call_count == 2
 
 
 def test_retrying_proxy_swh_storage_snapshot_add_failure(