Merge pull request ansible#4393 from kdelee/backport_dont_block_log_send

[3.7.1] don't block on log aggregator socket.send() calls

awx/main/utils/handlers.py

@@ -13,6 +13,10 @@ class RSysLogHandler(logging.handlers.SysLogHandler):
 
     append_nul = False
 
+    def _connect_unixsocket(self, address):
+        super(RSysLogHandler, self)._connect_unixsocket(address)
+        self.socket.setblocking(False)
+
     def emit(self, msg):
         if not settings.LOG_AGGREGATOR_ENABLED:
             return
@@ -26,6 +30,14 @@ def emit(self, msg):
             # unfortunately, we can't log that because...rsyslogd is down (and
             # would just us back ddown this code path)
             pass
+        except BlockingIOError:
+            # for <some reason>, rsyslogd is no longer reading from the domain socket, and
+            # we're unable to write any more to it without blocking (we've seen this behavior
+            # from time to time when logging is totally misconfigured;
+            # in this scenario, it also makes more sense to just drop the messages,
+            # because the alternative is blocking the socket.send() in the
+            # Python process, which we definitely don't want to do)
+            pass
 
 
 ColorHandler = logging.StreamHandler