Fix Prometheus metrics being negative (mixed up start/end) (#13584)

Fix:

 - https://github.com/matrix-org/synapse/pull/13535#discussion_r949582508
 - https://github.com/matrix-org/synapse/pull/13533#discussion_r949577244

1 files changed, 10 insertions, 0 deletions

diff --git a/synapse/handlers/federation_event.py b/synapse/handlers/federation_event.py

index 32326975a1..048c4111f6 100644
--- a/synapse/handlers/federation_event.py
+++ b/synapse/handlers/federation_event.py
@@ -104,15 +104,25 @@ backfill_processing_after_timer = Histogram(
     "sec",
     [],
     buckets=(
+        0.1,
+        0.25,
+        0.5,
         1.0,
+        2.5,
         5.0,
+        7.5,
         10.0,
+        15.0,
         20.0,
+        25.0,
         30.0,
         40.0,
+        50.0,
         60.0,
         80.0,
+        100.0,
         120.0,
+        150.0,
         180.0,
         "+Inf",
     ),