From 8d156ec0ba17d848581f18aa40ebfd76dda763d4 Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
Date: Fri, 29 Apr 2022 22:05:18 +0100
Subject: [PATCH] Remove special-case for `twisted` logger (#12589)

This was originally added when we first added a `MemoryHandler` to the default
log config back in https://github.com/matrix-org/synapse/pull/8040, to ensure
that we didn't explode with an infinite loop if there was an error formatting
the logs.

Since then, we made additional improvements to logging which make this
workaround redundant. In particular:

 * we no longer attempt to log un-UTF8-decodable byte sequences, which were the
   most likely cause of an error in the first place.

 * https://github.com/matrix-org/synapse/pull/8268 ensures that in the unlikely
   case that there *is* an error, it won't cause an infinite loop.
---
 changelog.d/12589.misc      | 1 +
 docs/sample_log_config.yaml | 7 -------
 synapse/config/logger.py    | 7 -------
 3 files changed, 1 insertion(+), 14 deletions(-)
 create mode 100644 changelog.d/12589.misc

diff --git a/changelog.d/12589.misc b/changelog.d/12589.misc
new file mode 100644
index 0000000000..d362828d2e
--- /dev/null
+++ b/changelog.d/12589.misc
@@ -0,0 +1 @@
+Remove special-case for `twisted` logger from default log config.
diff --git a/docs/sample_log_config.yaml b/docs/sample_log_config.yaml
index 2485ad25ed..3065a0e2d9 100644
--- a/docs/sample_log_config.yaml
+++ b/docs/sample_log_config.yaml
@@ -62,13 +62,6 @@ loggers:
         # information such as access tokens.
         level: INFO
 
-    twisted:
-        # We send the twisted logging directly to the file handler,
-        # to work around https://github.com/matrix-org/synapse/issues/3471
-        # when using "buffer" logger. Use "console" to log to stderr instead.
-        handlers: [file]
-        propagate: false
-
 root:
     level: INFO
 
diff --git a/synapse/config/logger.py b/synapse/config/logger.py
index 99db9e1e39..470b8b4492 100644
--- a/synapse/config/logger.py
+++ b/synapse/config/logger.py
@@ -110,13 +110,6 @@ loggers:
         # information such as access tokens.
         level: INFO
 
-    twisted:
-        # We send the twisted logging directly to the file handler,
-        # to work around https://github.com/matrix-org/synapse/issues/3471
-        # when using "buffer" logger. Use "console" to log to stderr instead.
-        handlers: [file]
-        propagate: false
-
 root:
     level: INFO