Remove stack traces from INFO and WARNING logs.

Fix #1501.

src/websockets/asyncio/client.py

@@ -3,6 +3,7 @@
 import asyncio
 import logging
 import os
+import traceback
 import urllib.parse
 from collections.abc import AsyncIterator, Generator, Sequence
 from types import TracebackType
@@ -521,9 +522,10 @@ async def __aiter__(self) -> AsyncIterator[ClientConnection]:
                     delays = backoff()
                 delay = next(delays)
                 self.logger.info(
-                    "connect failed; reconnecting in %.1f seconds",
+                    "connect failed; reconnecting in %.1f seconds: %s",
                     delay,
-                    exc_info=True,
+                    # Remove first argument when dropping Python 3.9.
+                    traceback.format_exception_only(type(exc), exc)[0].strip(),
                 )
                 await asyncio.sleep(delay)
                 continue

src/websockets/asyncio/connection.py

@@ -7,6 +7,7 @@
 import random
 import struct
 import sys
+import traceback
 import uuid
 from collections.abc import AsyncIterable, AsyncIterator, Awaitable, Iterable, Mapping
 from types import TracebackType
@@ -1180,8 +1181,12 @@ def broadcast(
                 exceptions.append(exception)
             else:
                 connection.logger.warning(
-                    "skipped broadcast: failed to write message",
-                    exc_info=True,
+                    "skipped broadcast: failed to write message: %s",
+                    traceback.format_exception_only(
+                        # Remove first argument when dropping Python 3.9.
+                        type(write_exception),
+                        write_exception,
+                    )[0].strip(),
                 )
 
     if raise_exceptions and exceptions:

src/websockets/legacy/client.py

@@ -5,6 +5,7 @@
 import logging
 import os
 import random
+import traceback
 import urllib.parse
 import warnings
 from collections.abc import AsyncIterator, Generator, Sequence
@@ -597,22 +598,24 @@ async def __aiter__(self) -> AsyncIterator[WebSocketClientProtocol]:
             try:
                 async with self as protocol:
                     yield protocol
-            except Exception:
+            except Exception as exc:
                 # Add a random initial delay between 0 and 5 seconds.
                 # See 7.2.3. Recovering from Abnormal Closure in RFC 6455.
                 if backoff_delay == self.BACKOFF_MIN:
                     initial_delay = random.random() * self.BACKOFF_INITIAL
                     self.logger.info(
-                        "connect failed; reconnecting in %.1f seconds",
+                        "connect failed; reconnecting in %.1f seconds: %s",
                         initial_delay,
-                        exc_info=True,
+                        # Remove first argument when dropping Python 3.9.
+                        traceback.format_exception_only(type(exc), exc)[0].strip(),
                     )
                     await asyncio.sleep(initial_delay)
                 else:
                     self.logger.info(
-                        "connect failed again; retrying in %d seconds",
+                        "connect failed again; retrying in %d seconds: %s",
                         int(backoff_delay),
-                        exc_info=True,
+                        # Remove first argument when dropping Python 3.9.
+                        traceback.format_exception_only(type(exc), exc)[0].strip(),
                     )
                     await asyncio.sleep(int(backoff_delay))
                 # Increase delay with truncated exponential backoff.

src/websockets/legacy/protocol.py

@@ -9,6 +9,7 @@
 import struct
 import sys
 import time
+import traceback
 import uuid
 import warnings
 from collections.abc import AsyncIterable, AsyncIterator, Awaitable, Iterable, Mapping
@@ -1624,8 +1625,12 @@ def broadcast(
                 exceptions.append(exception)
             else:
                 websocket.logger.warning(
-                    "skipped broadcast: failed to write message",
-                    exc_info=True,
+                    "skipped broadcast: failed to write message: %s",
+                    traceback.format_exception_only(
+                        # Remove first argument when dropping Python 3.9.
+                        type(write_exception),
+                        write_exception,
+                    )[0].strip(),
                 )
 
     if raise_exceptions and exceptions:

tests/asyncio/test_connection.py

@@ -1337,7 +1337,10 @@ async def test_broadcast_skips_connection_failing_to_send(self):
 
         self.assertEqual(
             [record.getMessage() for record in logs.records],
-            ["skipped broadcast: failed to write message"],
+            [
+                "skipped broadcast: failed to write message: "
+                "RuntimeError: Cannot call write() after write_eof()"
+            ],
         )
 
     @unittest.skipIf(

tests/legacy/test_client_server.py

@@ -1607,6 +1607,10 @@ async def run_client():
             ],
         )
         # Iteration 3
+        exc = (
+            "websockets.legacy.exceptions.InvalidStatusCode: "
+            "server rejected WebSocket connection: HTTP 503"
+        )
         self.assertEqual(
             [
                 re.sub(r"[0-9\.]+ seconds", "X seconds", record.getMessage())
@@ -1615,12 +1619,12 @@ async def run_client():
             [
                 "connection rejected (503 Service Unavailable)",
                 "connection closed",
-                "connect failed; reconnecting in X seconds",
+                f"connect failed; reconnecting in X seconds: {exc}",
             ]
             + [
                 "connection rejected (503 Service Unavailable)",
                 "connection closed",
-                "connect failed again; retrying in X seconds",
+                f"connect failed again; retrying in X seconds: {exc}",
             ]
             * ((len(logs.records) - 8) // 3)
             + [

tests/legacy/test_protocol.py

@@ -1547,14 +1547,14 @@ def test_broadcast_reports_connection_sending_fragmented_text(self):
 
     def test_broadcast_skips_connection_failing_to_send(self):
         # Configure mock to raise an exception when writing to the network.
-        self.protocol.transport.write.side_effect = RuntimeError
+        self.protocol.transport.write.side_effect = RuntimeError("BOOM")
 
         with self.assertLogs("websockets", logging.WARNING) as logs:
             broadcast([self.protocol], "café")
 
         self.assertEqual(
             [record.getMessage() for record in logs.records],
-            ["skipped broadcast: failed to write message"],
+            ["skipped broadcast: failed to write message: RuntimeError: BOOM"],
         )
 
     @unittest.skipIf(