diff --git a/zerver/context_processors.py b/zerver/context_processors.py
index c99e640adb..61d45fcf55 100644
--- a/zerver/context_processors.py
+++ b/zerver/context_processors.py
@@ -17,6 +17,7 @@ from version import (
 from zerver.lib.exceptions import InvalidSubdomainError
 from zerver.lib.realm_description import get_realm_rendered_description, get_realm_text_description
 from zerver.lib.realm_icon import get_realm_icon_url
+from zerver.lib.request import get_request_notes
 from zerver.lib.send_email import FromAddress
 from zerver.lib.subdomains import get_subdomain
 from zerver.models import Realm, UserProfile, get_realm
@@ -50,19 +51,22 @@ def common_context(user: UserProfile) -> Dict[str, Any]:
 
 
 def get_realm_from_request(request: HttpRequest) -> Optional[Realm]:
+    request_notes = get_request_notes(request)
     if hasattr(request, "user") and hasattr(request.user, "realm"):
         return request.user.realm
-    if not hasattr(request, "realm"):
-        # We cache the realm object from this function on the request,
+    if not request_notes.has_fetched_realm:
+        # We cache the realm object from this function on the request data,
         # so that functions that call get_realm_from_request don't
         # need to do duplicate queries on the same realm while
         # processing a single request.
         subdomain = get_subdomain(request)
+        request_notes = get_request_notes(request)
         try:
-            request.realm = get_realm(subdomain)
+            request_notes.realm = get_realm(subdomain)
         except Realm.DoesNotExist:
-            request.realm = None
-    return request.realm
+            request_notes.realm = None
+        request_notes.has_fetched_realm = True
+    return request_notes.realm
 
 
 def get_valid_realm_from_request(request: HttpRequest) -> Realm:
diff --git a/zerver/middleware.py b/zerver/middleware.py
index 60ac926538..6c42973322 100644
--- a/zerver/middleware.py
+++ b/zerver/middleware.py
@@ -577,10 +577,12 @@ class HostDomainMiddleware(MiddlewareMixin):
 
         subdomain = get_subdomain(request)
         if subdomain != Realm.SUBDOMAIN_FOR_ROOT_DOMAIN:
+            request_notes = get_request_notes(request)
             try:
-                request.realm = get_realm(subdomain)
+                request_notes.realm = get_realm(subdomain)
             except Realm.DoesNotExist:
                 return render(request, "zerver/invalid_realm.html", status=404)
+            request_notes.has_fetched_realm = True
         return None
 
 
diff --git a/zerver/views/archive.py b/zerver/views/archive.py
index ed6cd72608..28e8cbf48e 100644
--- a/zerver/views/archive.py
+++ b/zerver/views/archive.py
@@ -6,6 +6,7 @@ from django.template import loader
 
 from zerver.lib.avatar import get_gravatar_url
 from zerver.lib.exceptions import JsonableError
+from zerver.lib.request import get_request_notes
 from zerver.lib.response import json_success
 from zerver.lib.streams import access_web_public_stream
 from zerver.lib.timestamp import datetime_to_timestamp
@@ -29,7 +30,9 @@ def archive(request: HttpRequest, stream_id: int, topic_name: str) -> HttpRespon
         )
 
     try:
-        stream = access_web_public_stream(stream_id, request.realm)
+        realm = get_request_notes(request).realm
+        assert realm is not None
+        stream = access_web_public_stream(stream_id, realm)
     except JsonableError:
         return get_response([], False, "")
 
@@ -75,7 +78,9 @@ def archive(request: HttpRequest, stream_id: int, topic_name: str) -> HttpRespon
 
 def get_web_public_topics_backend(request: HttpRequest, stream_id: int) -> HttpResponse:
     try:
-        stream = access_web_public_stream(stream_id, request.realm)
+        realm = get_request_notes(request).realm
+        assert realm is not None
+        stream = access_web_public_stream(stream_id, realm)
     except JsonableError:
         return json_success(dict(topics=[]))
 
diff --git a/zproject/sentry.py b/zproject/sentry.py
index a260f6bc42..45466361c8 100644
--- a/zproject/sentry.py
+++ b/zproject/sentry.py
@@ -10,6 +10,7 @@ from sentry_sdk.integrations.sqlalchemy import SqlalchemyIntegration
 from sentry_sdk.utils import capture_internal_exceptions
 
 from version import ZULIP_VERSION
+from zerver.lib.request import get_request_notes
 
 from .config import PRODUCTION, STAGING
 
@@ -50,10 +51,11 @@ def add_context(event: "Event", hint: "Hint") -> Optional["Event"]:
 
         request = get_current_request()
         if request:
+            request_notes = get_request_notes(request)
             if hasattr(request, "client"):
                 event["tags"]["client"] = request.client.name
-            if hasattr(request, "realm"):
-                event["tags"].setdefault("realm", request.realm.string_id)
+            if request_notes.realm is not None:
+                event["tags"].setdefault("realm", request_notes.realm.string_id)
     return event