From 3d882a7ba52114f18ec6be61c51561db203a0534 Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
Date: Thu, 12 Sep 2019 13:00:13 +0100
Subject: [PATCH] Remove the cap on federation retry interval. (#6026)

Essentially the intention here is to end up blacklisting servers which never
respond to federation requests.

Fixes https://github.com/matrix-org/synapse/issues/5113.
---
 changelog.d/6026.feature   | 1 +
 synapse/util/retryutils.py | 4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)
 create mode 100644 changelog.d/6026.feature

diff --git a/changelog.d/6026.feature b/changelog.d/6026.feature
new file mode 100644
index 000000000..2489ff09b
--- /dev/null
+++ b/changelog.d/6026.feature
@@ -0,0 +1 @@
+Stop sending federation transactions to servers which have been down for a long time.
diff --git a/synapse/util/retryutils.py b/synapse/util/retryutils.py
index 33263fe20..b740913b5 100644
--- a/synapse/util/retryutils.py
+++ b/synapse/util/retryutils.py
@@ -28,8 +28,8 @@ MIN_RETRY_INTERVAL = 10 * 60 * 1000
 # how much we multiply the backoff by after each subsequent fail
 RETRY_MULTIPLIER = 5
 
-# a cap on the backoff
-MAX_RETRY_INTERVAL = 24 * 60 * 60 * 1000
+# a cap on the backoff. (Essentially none)
+MAX_RETRY_INTERVAL = 2 ** 63
 
 
 class NotRetryingDestination(Exception):