From 52c60bd0a96cd61583209a9ef6d8270425e8a902 Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
Date: Thu, 17 Jun 2021 11:21:53 +0100
Subject: [PATCH] Fix persist_events to stop leaking opentracing contexts
 (#10193)

---
 changelog.d/10193.misc            | 1 +
 synapse/storage/persist_events.py | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)
 create mode 100644 changelog.d/10193.misc

diff --git a/changelog.d/10193.misc b/changelog.d/10193.misc
new file mode 100644
index 0000000000..ce9702645d
--- /dev/null
+++ b/changelog.d/10193.misc
@@ -0,0 +1 @@
+Improve OpenTracing for event persistence.
diff --git a/synapse/storage/persist_events.py b/synapse/storage/persist_events.py
index dc38942bb1..051095fea9 100644
--- a/synapse/storage/persist_events.py
+++ b/synapse/storage/persist_events.py
@@ -111,7 +111,7 @@ class _EventPersistQueueItem:
     backfilled: bool
     deferred: ObservableDeferred
 
-    parent_opentracing_span_contexts: List = []
+    parent_opentracing_span_contexts: List = attr.ib(factory=list)
     """A list of opentracing spans waiting for this batch"""
 
     opentracing_span_context: Any = None