From 17d6c2828557cb39f24bfbf2816b45fe1990122d Mon Sep 17 00:00:00 2001
From: reivilibre <oliverw@matrix.org>
Date: Fri, 7 Jun 2024 12:01:21 +0100
Subject: [PATCH] Add debug logging for when room keys are uploaded, including
 whether they are replacing other room keys. (#17266)

Fixes: #17013

Add logging for whether room keys are replaced
This is motivated by the Crypto team who need to diagnose crypto issues.

The existing opentracing logging is not enough because it is not enabled
for all users.
---
 changelog.d/17266.misc            |  1 +
 synapse/handlers/e2e_room_keys.py | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+)
 create mode 100644 changelog.d/17266.misc

diff --git a/changelog.d/17266.misc b/changelog.d/17266.misc
new file mode 100644
index 0000000000..ce8c4ab086
--- /dev/null
+++ b/changelog.d/17266.misc
@@ -0,0 +1 @@
+Add debug logging for when room keys are uploaded, including whether they are replacing other room keys.
\ No newline at end of file
diff --git a/synapse/handlers/e2e_room_keys.py b/synapse/handlers/e2e_room_keys.py
index e76a51ba30..99f9f6e64a 100644
--- a/synapse/handlers/e2e_room_keys.py
+++ b/synapse/handlers/e2e_room_keys.py
@@ -247,6 +247,12 @@ class E2eRoomKeysHandler:
                     if current_room_key:
                         if self._should_replace_room_key(current_room_key, room_key):
                             log_kv({"message": "Replacing room key."})
+                            logger.debug(
+                                "Replacing room key. room=%s session=%s user=%s",
+                                room_id,
+                                session_id,
+                                user_id,
+                            )
                             # updates are done one at a time in the DB, so send
                             # updates right away rather than batching them up,
                             # like we do with the inserts
@@ -256,6 +262,12 @@ class E2eRoomKeysHandler:
                             changed = True
                         else:
                             log_kv({"message": "Not replacing room_key."})
+                            logger.debug(
+                                "Not replacing room key. room=%s session=%s user=%s",
+                                room_id,
+                                session_id,
+                                user_id,
+                            )
                     else:
                         log_kv(
                             {
@@ -265,6 +277,12 @@ class E2eRoomKeysHandler:
                             }
                         )
                         log_kv({"message": "Replacing room key."})
+                        logger.debug(
+                            "Inserting new room key. room=%s session=%s user=%s",
+                            room_id,
+                            session_id,
+                            user_id,
+                        )
                         to_insert.append((room_id, session_id, room_key))
                         changed = True