From 23f05c8b466a4bc8e58ca732bc7b71b0c3c83ab1 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Fri, 6 Nov 2020 12:35:10 +0000
Subject: [PATCH 1/2] Enable reconnection in DB pool

---
 synapse/storage/database.py | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/synapse/storage/database.py b/synapse/storage/database.py
index a0572b295239..d1b5760c2c09 100644
--- a/synapse/storage/database.py
+++ b/synapse/storage/database.py
@@ -88,13 +88,18 @@ def make_pool(
     """Get the connection pool for the database.
     """
 
+    # By default enable `cp_reconnect`. We need to fiddle with db_args in case
+    # someone has explicitly set `cp_reconnect`.
+    db_args = dict(db_config.config.get("args", {}))
+    db_args.setdefault("cp_reconnect", True)
+
     return adbapi.ConnectionPool(
         db_config.config["name"],
         cp_reactor=reactor,
         cp_openfun=lambda conn: engine.on_new_connection(
             LoggingDatabaseConnection(conn, engine, "on_new_connection")
         ),
-        **db_config.config.get("args", {}),
+        **db_args,
     )
 
 

From 45ebae8e5df45ff453c10145ea0276419c509454 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Fri, 6 Nov 2020 12:40:02 +0000
Subject: [PATCH 2/2] Newsfile

---
 changelog.d/8726.bugfix | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changelog.d/8726.bugfix

diff --git a/changelog.d/8726.bugfix b/changelog.d/8726.bugfix
new file mode 100644
index 000000000000..831f773a25e4
--- /dev/null
+++ b/changelog.d/8726.bugfix
@@ -0,0 +1 @@
+Fix bug where Synapse would not recover after losing connection to the database.