diff --git a/changelog.d/3872.misc b/changelog.d/3872.misc
new file mode 100644
index 0000000000000000000000000000000000000000..b450c506d87321ec7bba774feaf07a8081570866
--- /dev/null
+++ b/changelog.d/3872.misc
@@ -0,0 +1 @@
+Disable buffering and automatic retrying in treq requests to prevent timeouts.
\ No newline at end of file
diff --git a/synapse/http/__init__.py b/synapse/http/__init__.py
index 58ef8d3ce4618b2150f44f4cbf7c20788deed4a3..a3f9e4f67ce41a543dbc3d68f44400ebd0245136 100644
--- a/synapse/http/__init__.py
+++ b/synapse/http/__init__.py
@@ -38,12 +38,12 @@ def cancelled_to_request_timed_out_error(value, timeout):
     return value
 
 
-ACCESS_TOKEN_RE = re.compile(br'(\?.*access(_|%5[Ff])token=)[^&]*(.*)$')
+ACCESS_TOKEN_RE = re.compile(r'(\?.*access(_|%5[Ff])token=)[^&]*(.*)$')
 
 
 def redact_uri(uri):
     """Strips access tokens from the uri replaces with <redacted>"""
     return ACCESS_TOKEN_RE.sub(
-        br'\1<redacted>\3',
+        r'\1<redacted>\3',
         uri
     )
diff --git a/synapse/http/client.py b/synapse/http/client.py
index d60f87b04ea0e2112c765b2903196199a1184194..ec339a92ade587911bb049f82400d5bfe711e7a2 100644
--- a/synapse/http/client.py
+++ b/synapse/http/client.py
@@ -93,7 +93,7 @@ class SimpleHttpClient(object):
         outgoing_requests_counter.labels(method).inc()
 
         # log request but strip `access_token` (AS requests for example include this)
-        logger.info("Sending request %s %s", method, redact_uri(uri.encode('ascii')))
+        logger.info("Sending request %s %s", method, redact_uri(uri))
 
         try:
             request_deferred = treq.request(
@@ -108,14 +108,14 @@ class SimpleHttpClient(object):
             incoming_responses_counter.labels(method, response.code).inc()
             logger.info(
                 "Received response to  %s %s: %s",
-                method, redact_uri(uri.encode('ascii')), response.code
+                method, redact_uri(uri), response.code
             )
             defer.returnValue(response)
         except Exception as e:
             incoming_responses_counter.labels(method, "ERR").inc()
             logger.info(
                 "Error sending request to  %s %s: %s %s",
-                method, redact_uri(uri.encode('ascii')), type(e).__name__, e.args[0]
+                method, redact_uri(uri), type(e).__name__, e.args[0]
             )
             raise
 
diff --git a/synapse/http/matrixfederationclient.py b/synapse/http/matrixfederationclient.py
index c3542b93532029037db66d0901c2d92f0978ce42..da16b5dd8cd793734c495d141d718407237f3198 100644
--- a/synapse/http/matrixfederationclient.py
+++ b/synapse/http/matrixfederationclient.py
@@ -92,6 +92,7 @@ class MatrixFederationHttpClient(object):
         self.server_name = hs.hostname
         reactor = hs.get_reactor()
         pool = HTTPConnectionPool(reactor)
+        pool.retryAutomatically = False
         pool.maxPersistentPerHost = 5
         pool.cachedConnectionTimeout = 2 * 60
         self.agent = Agent.usingEndpointFactory(
@@ -222,7 +223,8 @@ class MatrixFederationHttpClient(object):
                         headers=Headers(headers_dict),
                         data=data,
                         agent=self.agent,
-                        reactor=self.hs.get_reactor()
+                        reactor=self.hs.get_reactor(),
+                        unbuffered=True
                     )
                     request_deferred.addTimeout(_sec_timeout, self.hs.get_reactor())
 
diff --git a/synapse/http/site.py b/synapse/http/site.py
index f0828c654243229f60993757d70ab391e85c3207..e1e53e8ae5f7c13469f923b6fa166e14eec8fd3b 100644
--- a/synapse/http/site.py
+++ b/synapse/http/site.py
@@ -85,7 +85,10 @@ class SynapseRequest(Request):
         return "%s-%i" % (self.method, self.request_seq)
 
     def get_redacted_uri(self):
-        return redact_uri(self.uri)
+        uri = self.uri
+        if isinstance(uri, bytes):
+            uri = self.uri.decode('ascii')
+        return redact_uri(uri)
 
     def get_user_agent(self):
         return self.requestHeaders.getRawHeaders(b"User-Agent", [None])[-1]