diff --git a/services/issue_svc.py b/services/issue_svc.py
index 8e5a45f..ad50f81 100644
--- a/services/issue_svc.py
+++ b/services/issue_svc.py
@@ -1,7 +1,6 @@
-# Copyright 2016 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style
-# license that can be found in the LICENSE file or at
-# https://developers.google.com/open-source/licenses/bsd
+# Copyright 2016 The Chromium Authors
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
 
 """A set of functions that provide persistence for Monorail issue tracking.
 
@@ -37,8 +36,8 @@
 from framework import permissions
 from framework import sql
 from infra_libs import ts_mon
-from proto import project_pb2
-from proto import tracker_pb2
+from mrproto import project_pb2
+from mrproto import tracker_pb2
 from services import caches
 from services import tracker_fulltext
 from tracker import tracker_bizobj
@@ -78,10 +77,10 @@
 
 ISSUE_COLS = [
     'id', 'project_id', 'local_id', 'status_id', 'owner_id', 'reporter_id',
-    'opened', 'closed', 'modified',
-    'owner_modified', 'status_modified', 'component_modified',
-    'derived_owner_id', 'derived_status_id',
-    'deleted', 'star_count', 'attachment_count', 'is_spam']
+    'opened', 'closed', 'modified', 'owner_modified', 'status_modified',
+    'component_modified', 'migration_modified', 'derived_owner_id',
+    'derived_status_id', 'deleted', 'star_count', 'attachment_count', 'is_spam'
+]
 ISSUESUMMARY_COLS = ['issue_id', 'summary']
 ISSUE2LABEL_COLS = ['issue_id', 'label_id', 'derived']
 ISSUE2COMPONENT_COLS = ['issue_id', 'component_id', 'derived']
@@ -111,7 +110,9 @@
     'ext_issue_identifier', 'kind']
 ISSUEUPDATE_COLS = [
     'id', 'issue_id', 'comment_id', 'field', 'old_value', 'new_value',
-    'added_user_id', 'removed_user_id', 'custom_field_name']
+    'added_user_id', 'removed_user_id', 'custom_field_name',
+    'added_component_id', 'removed_component_id'
+]
 ISSUEFORMERLOCATIONS_COLS = ['issue_id', 'project_id', 'local_id']
 REINDEXQUEUE_COLS = ['issue_id', 'created']
 ISSUESNAPSHOT_COLS = ['id', 'issue_id', 'shard', 'project_id', 'local_id',
@@ -188,10 +189,12 @@
 
   def _UnpackIssue(self, cnxn, issue_row):
     """Partially construct an issue object using info from a DB row."""
-    (issue_id, project_id, local_id, status_id, owner_id, reporter_id,
-     opened, closed, modified, owner_modified, status_modified,
-     component_modified, derived_owner_id, derived_status_id,
-     deleted, star_count, attachment_count, is_spam) = issue_row
+    (
+        issue_id, project_id, local_id, status_id, owner_id, reporter_id,
+        opened, closed, modified, owner_modified, status_modified,
+        component_modified, migration_modified, derived_owner_id,
+        derived_status_id, deleted, star_count, attachment_count,
+        is_spam) = issue_row
 
     issue = tracker_pb2.Issue()
     project = self.project_service.GetProject(cnxn, project_id)
@@ -222,6 +225,8 @@
       issue.status_modified_timestamp = status_modified
     if component_modified:
       issue.component_modified_timestamp = component_modified
+    if migration_modified:
+      issue.migration_modified_timestamp = migration_modified
     issue.star_count = star_count
     issue.attachment_count = attachment_count
     issue.is_spam = bool(is_spam)
@@ -361,7 +366,7 @@
       elif kind == 'mergedinto':
         src_issue.merged_into_external = ext_id
       else:
-        logging.warn('unhandled danging relation kind %r', kind)
+        logging.warning('unhandled danging relation kind %r', kind)
         continue
 
     return results_dict
@@ -1035,21 +1040,15 @@
     """
     status_id = self._config_service.LookupStatusID(
         cnxn, issue.project_id, issue.status)
-    row = (issue.project_id, issue.local_id, status_id,
-           issue.owner_id or None,
-           issue.reporter_id,
-           issue.opened_timestamp,
-           issue.closed_timestamp,
-           issue.modified_timestamp,
-           issue.owner_modified_timestamp,
-           issue.status_modified_timestamp,
-           issue.component_modified_timestamp,
-           issue.derived_owner_id or None,
-           self._config_service.LookupStatusID(
-               cnxn, issue.project_id, issue.derived_status),
-           bool(issue.deleted),
-           issue.star_count, issue.attachment_count,
-           issue.is_spam)
+    row = (
+        issue.project_id, issue.local_id, status_id, issue.owner_id or
+        None, issue.reporter_id, issue.opened_timestamp, issue.closed_timestamp,
+        issue.modified_timestamp, issue.owner_modified_timestamp,
+        issue.status_modified_timestamp, issue.component_modified_timestamp,
+        issue.migration_modified_timestamp, issue.derived_owner_id or None,
+        self._config_service.LookupStatusID(
+            cnxn, issue.project_id, issue.derived_status), bool(issue.deleted),
+        issue.star_count, issue.attachment_count, issue.is_spam)
     # ISSUE_COLs[1:] to skip setting the ID
     # Insert into the Primary DB.
     generated_ids = self.issue_tbl.InsertRows(
@@ -1095,25 +1094,43 @@
       assert not issue.assume_stale, (
           'issue2514: Storing issue that might be stale: %r' % issue)
       delta = {
-          'project_id': issue.project_id,
-          'local_id': issue.local_id,
-          'owner_id': issue.owner_id or None,
-          'status_id': self._config_service.LookupStatusID(
-              cnxn, issue.project_id, issue.status) or None,
-          'opened': issue.opened_timestamp,
-          'closed': issue.closed_timestamp,
-          'modified': issue.modified_timestamp,
-          'owner_modified': issue.owner_modified_timestamp,
-          'status_modified': issue.status_modified_timestamp,
-          'component_modified': issue.component_modified_timestamp,
-          'derived_owner_id': issue.derived_owner_id or None,
-          'derived_status_id': self._config_service.LookupStatusID(
-              cnxn, issue.project_id, issue.derived_status) or None,
-          'deleted': bool(issue.deleted),
-          'star_count': issue.star_count,
-          'attachment_count': issue.attachment_count,
-          'is_spam': issue.is_spam,
-          }
+          'project_id':
+              issue.project_id,
+          'local_id':
+              issue.local_id,
+          'owner_id':
+              issue.owner_id or None,
+          'status_id':
+              self._config_service.LookupStatusID(
+                  cnxn, issue.project_id, issue.status) or None,
+          'opened':
+              issue.opened_timestamp,
+          'closed':
+              issue.closed_timestamp,
+          'modified':
+              issue.modified_timestamp,
+          'owner_modified':
+              issue.owner_modified_timestamp,
+          'status_modified':
+              issue.status_modified_timestamp,
+          'component_modified':
+              issue.component_modified_timestamp,
+          'migration_modified':
+              issue.migration_modified_timestamp,
+          'derived_owner_id':
+              issue.derived_owner_id or None,
+          'derived_status_id':
+              self._config_service.LookupStatusID(
+                  cnxn, issue.project_id, issue.derived_status) or None,
+          'deleted':
+              bool(issue.deleted),
+          'star_count':
+              issue.star_count,
+          'attachment_count':
+              issue.attachment_count,
+          'is_spam':
+              issue.is_spam,
+      }
       if update_cols is not None:
         delta = {key: val for key, val in delta.items()
                  if key in update_cols}
@@ -1514,6 +1531,7 @@
     # update the modified_timestamp for any comment added, even if it was
     # just a text comment with no issue fields changed.
     issue.modified_timestamp = timestamp
+    issue.migration_modified_timestamp = timestamp
 
     # Update the closed timestamp before filter rules so that rules
     # can test for closed_timestamp, and also after filter rules
@@ -1791,7 +1809,8 @@
     """
     issue = self.GetIssueByLocalID(cnxn, project_id, local_id, use_cache=False)
     issue.deleted = deleted
-    self.UpdateIssue(cnxn, issue, update_cols=['deleted'])
+    issue.migration_modified_timestamp = int(time.time())
+    self.UpdateIssue(cnxn, issue, update_cols=['deleted', 'migration_modified'])
     tracker_fulltext.IndexIssues(
         cnxn, [issue], user_service, self, self._config_service)
 
@@ -1910,9 +1929,10 @@
 
   def _UnpackAmendment(self, amendment_row):
     """Construct an Amendment PB from a DB row."""
-    (_id, _issue_id, comment_id, field_name,
-     old_value, new_value, added_user_id, removed_user_id,
-     custom_field_name) = amendment_row
+    (
+        _id, _issue_id, comment_id, field_name, old_value, new_value,
+        added_user_id, removed_user_id, custom_field_name, added_component_id,
+        removed_component_id) = amendment_row
     amendment = tracker_pb2.Amendment()
     field_enum = tracker_pb2.FieldID(field_name.upper())
     amendment.field = field_enum
@@ -1928,6 +1948,12 @@
       amendment.removed_user_ids.append(removed_user_id)
     if custom_field_name:
       amendment.custom_field_name = custom_field_name
+    if added_component_id:
+      added_component_id = int(added_component_id)
+      amendment.added_component_ids.append(added_component_id)
+    if removed_component_id:
+      removed_component_id = int(removed_component_id)
+      amendment.removed_component_ids.append(removed_component_id)
     return amendment, comment_id
 
   def _ConsolidateAmendments(self, amendments):
@@ -1962,6 +1988,12 @@
           new_amendment.removed_user_ids.extend(amendment.removed_user_ids)
         if amendment.custom_field_name:
           new_amendment.custom_field_name = amendment.custom_field_name
+        if amendment.added_component_ids:
+          new_amendment.added_component_ids.extend(
+              amendment.added_component_ids)
+        if amendment.removed_component_ids:
+          new_amendment.removed_component_ids.extend(
+              amendment.removed_component_ids)
       result.append(new_amendment)
     return result
 
@@ -2164,18 +2196,31 @@
       field_enum = str(amendment.field).lower()
       if (amendment.get_assigned_value('newvalue') is not None and
           not amendment.added_user_ids and not amendment.removed_user_ids):
-        amendment_rows.append((
-            comment.issue_id, comment_id, field_enum,
-            amendment.oldvalue, amendment.newvalue,
-            None, None, amendment.custom_field_name))
+        amendment_rows.append(
+            (
+                comment.issue_id, comment_id, field_enum, amendment.oldvalue,
+                amendment.newvalue, None, None, amendment.custom_field_name,
+                None, None))
       for added_user_id in amendment.added_user_ids:
-        amendment_rows.append((
-            comment.issue_id, comment_id, field_enum, None, None,
-            added_user_id, None, amendment.custom_field_name))
+        amendment_rows.append(
+            (
+                comment.issue_id, comment_id, field_enum, None, None,
+                added_user_id, None, amendment.custom_field_name, None, None))
       for removed_user_id in amendment.removed_user_ids:
-        amendment_rows.append((
-            comment.issue_id, comment_id, field_enum, None, None,
-            None, removed_user_id, amendment.custom_field_name))
+        amendment_rows.append(
+            (
+                comment.issue_id, comment_id, field_enum, None, None, None,
+                removed_user_id, amendment.custom_field_name, None, None))
+      for added_component_id in amendment.added_component_ids:
+        amendment_rows.append(
+            (
+                comment.issue_id, comment_id, field_enum, None, None, None,
+                None, amendment.custom_field_name, added_component_id, None))
+      for removed_component_id in amendment.removed_component_ids:
+        amendment_rows.append(
+            (
+                comment.issue_id, comment_id, field_enum, None, None, None,
+                None, amendment.custom_field_name, None, removed_component_id))
     # ISSUEUPDATE_COLS[1:] to skip id column.
     self.issueupdate_tbl.InsertRows(
         cnxn, ISSUEUPDATE_COLS[1:], amendment_rows, commit=False)
@@ -2369,16 +2414,19 @@
       if not issue_comment.deleted_by:
         issue_comment.deleted_by = deleted_by_user_id
         issue.attachment_count = issue.attachment_count - attachments
+        issue.migration_modified_timestamp = int(time.time())
 
     # Undelete only if it's in deleted state
     elif issue_comment.deleted_by:
       issue_comment.deleted_by = 0
       issue.attachment_count = issue.attachment_count + attachments
+      issue.migration_modified_timestamp = int(time.time())
 
     issue_comment.is_spam = is_spam
     self._UpdateComment(
         cnxn, issue_comment, update_cols=['deleted_by', 'is_spam'])
-    self.UpdateIssue(cnxn, issue, update_cols=['attachment_count'])
+    self.UpdateIssue(
+        cnxn, issue, update_cols=['attachment_count', 'migration_modified'])
 
     # Reindex the issue to take the comment deletion/undeletion into account.
     if reindex:
@@ -2576,10 +2624,12 @@
       if delete:
         if not attachment.deleted:
           issue.attachment_count = issue.attachment_count - 1
+          issue.migration_modified_timestamp = int(time.time())
 
       # Increment attachment count only if it's in deleted state
       elif attachment.deleted:
         issue.attachment_count = issue.attachment_count + 1
+        issue.migration_modified_timestamp = int(time.time())
 
     logging.info('attachment.deleted was %s', attachment.deleted)
 
@@ -2589,7 +2639,8 @@
 
     self._UpdateAttachment(
         cnxn, issue_comment, attachment, update_cols=['deleted'])
-    self.UpdateIssue(cnxn, issue, update_cols=['attachment_count'])
+    self.UpdateIssue(
+        cnxn, issue, update_cols=['attachment_count', 'migration_modified'])
 
     if index_now:
       tracker_fulltext.IndexIssues(
@@ -2782,9 +2833,11 @@
     user_ids = list(user_ids_by_email.values())
     user_emails = list(user_ids_by_email.keys())
     # Track issue_ids for issues that will have different search documents
-    # as a result of removing users.
+    # and need updates to modification time as a result of removing users.
     affected_issue_ids = []
 
+    timestamp = int(time.time())
+
     # Reassign commenter_id and delete inbound_messages.
     shard_id = sql.RandomShardID()
     comment_content_id_rows = self.comment_tbl.Select(
@@ -2868,6 +2921,18 @@
     # User rows can be deleted safely. No limit will be applied.
 
     # Remove users in issue updates.
+    user_added_id_rows = self.issueupdate_tbl.Select(
+        cnxn,
+        cols=['IssueUpdate.issue_id'],
+        added_user_id=user_ids,
+        shard_id=shard_id,
+        limit=limit)
+    user_removed_id_rows = self.issueupdate_tbl.Select(
+        cnxn,
+        cols=['IssueUpdate.issue_id'],
+        removed_user_id=user_ids,
+        shard_id=shard_id,
+        limit=limit)
     self.issueupdate_tbl.Update(
         cnxn,
         {'added_user_id': framework_constants.DELETED_USER_ID},
@@ -2878,6 +2943,8 @@
         {'removed_user_id': framework_constants.DELETED_USER_ID},
         removed_user_id=user_ids,
         commit=commit)
+    affected_issue_ids.extend([row[0] for row in user_added_id_rows])
+    affected_issue_ids.extend([row[0] for row in user_removed_id_rows])
 
     # Remove users in issue notify.
     self.issue2notify_tbl.Delete(
@@ -2897,4 +2964,12 @@
     self.issuesnapshot2cc_tbl.Delete(
         cnxn, cc_id=user_ids, commit=commit, limit=limit)
 
-    return list(set(affected_issue_ids))
+    # Update migration_modified timestamp for affected issues.
+    deduped_issue_ids = list(set(affected_issue_ids))
+    if deduped_issue_ids:
+      self.issue_tbl.Update(
+          cnxn, {'migration_modified': timestamp},
+          id=deduped_issue_ids,
+          commit=commit)
+
+    return deduped_issue_ids