From adfdd6afe120d13ec6cd9d8a1d72b6fba5d8c9f8 Mon Sep 17 00:00:00 2001
From: "Olivier Wilkinson (reivilibre)" <oliverw@matrix.org>
Date: Tue, 17 Oct 2023 11:42:24 +0100
Subject: [PATCH] TEMPORARY Measure and log test cases

---
 .../databases/main/event_federation.py        | 23 ++++++++++++++-----
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/synapse/storage/databases/main/event_federation.py b/synapse/storage/databases/main/event_federation.py
index afffa54985..29fb5b7b66 100644
--- a/synapse/storage/databases/main/event_federation.py
+++ b/synapse/storage/databases/main/event_federation.py
@@ -54,6 +54,7 @@ from synapse.util.caches.descriptors import cached
 from synapse.util.caches.lrucache import LruCache
 from synapse.util.cancellation import cancellable
 from synapse.util.iterutils import batch_iter
+from synapse.util.metrics import Measure
 
 if TYPE_CHECKING:
     from synapse.server import HomeServer
@@ -413,12 +414,22 @@ class EventFederationWorkerStore(SignatureWorkerStore, EventsWorkerStore, SQLBas
         room = await self.get_room(room_id)  # type: ignore[attr-defined]
         if room["has_auth_chain_index"]:
             try:
-                return await self.db_pool.runInteraction(
-                    "get_auth_chain_difference_chains",
-                    self._get_auth_chain_difference_using_cover_index_txn,
-                    room_id,
-                    state_sets,
-                )
+                with Measure(self.hs.get_clock(), "rei:get_auth_chain_difference_chains") as m:
+                    r = await self.db_pool.runInteraction(
+                        "get_auth_chain_difference_chains",
+                        self._get_auth_chain_difference_using_cover_index_txn,
+                        room_id,
+                        state_sets,
+                    )
+                    if m.get_resource_usage().ru_utime > 4.0:
+                        logger.info(
+                            "REI-ACDC %.2f, ri=%r ss=%r",
+                            m.get_resource_usage().ru_utime,
+                            room_id,
+                            state_sets
+                        )
+                    return r
+
             except _NoChainCoverIndex:
                 # For whatever reason we don't actually have a chain cover index
                 # for the events in question, so we fall back to the old method.