diff --git a/src/shrpx_client_handler.cc b/src/shrpx_client_handler.cc
index 4feb973c..bf72a907 100644
--- a/src/shrpx_client_handler.cc
+++ b/src/shrpx_client_handler.cc
@@ -770,34 +770,73 @@ Http2Session *ClientHandler::select_http2_session(
   auto &http2_avail_freelist = shared_addr->http2_avail_freelist;
 
   if (http2_avail_freelist.size() >= min) {
-    auto session = http2_avail_freelist.head;
-    session->remove_from_freelist();
+    for (auto session = http2_avail_freelist.head; session;) {
+      auto next = session->dlnext;
 
-    if (LOG_ENABLED(INFO)) {
-      CLOG(INFO, this) << "Use Http2Session " << session
-                       << " from http2_avail_freelist";
-    }
+      session->remove_from_freelist();
 
-    if (session->max_concurrency_reached(1)) {
-      if (LOG_ENABLED(INFO)) {
-        CLOG(INFO, this) << "Maximum streams are reached for Http2Session("
-                         << session << ").";
+      // session may be in graceful shutdown period now.
+      if (session->max_concurrency_reached(0)) {
+        if (LOG_ENABLED(INFO)) {
+          CLOG(INFO, this)
+              << "Maximum streams have been reached for Http2Session("
+              << session << ").  Skip it";
+        }
+
+        session = next;
+
+        continue;
       }
-    } else {
-      session->add_to_avail_freelist();
+
+      if (LOG_ENABLED(INFO)) {
+        CLOG(INFO, this) << "Use Http2Session " << session
+                         << " from http2_avail_freelist";
+      }
+
+      if (session->max_concurrency_reached(1)) {
+        if (LOG_ENABLED(INFO)) {
+          CLOG(INFO, this) << "Maximum streams are reached for Http2Session("
+                           << session << ").";
+        }
+      } else {
+        session->add_to_avail_freelist();
+      }
+      return session;
     }
-    return session;
   }
 
   DownstreamAddr *selected_addr = nullptr;
 
   for (auto &addr : shared_addr->addrs) {
-    if (addr.proto != PROTO_HTTP2 || (addr.http2_extra_freelist.size() == 0 &&
-                                      addr.connect_blocker->blocked())) {
+    if (addr.in_avail || addr.proto != PROTO_HTTP2 ||
+        (addr.http2_extra_freelist.size() == 0 &&
+         addr.connect_blocker->blocked())) {
       continue;
     }
 
-    if (addr.in_avail) {
+    for (auto session = addr.http2_extra_freelist.head; session;) {
+      auto next = session->dlnext;
+
+      // session may be in graceful shutdown period now.
+      if (session->max_concurrency_reached(0)) {
+        if (LOG_ENABLED(INFO)) {
+          CLOG(INFO, this)
+              << "Maximum streams have been reached for Http2Session("
+              << session << ").  Skip it";
+        }
+
+        session->remove_from_freelist();
+
+        session = next;
+
+        continue;
+      }
+
+      break;
+    }
+
+    if (addr.http2_extra_freelist.size() == 0 &&
+        addr.connect_blocker->blocked()) {
       continue;
     }
 
diff --git a/src/shrpx_connection_handler.cc b/src/shrpx_connection_handler.cc
index 50f54664..ae9ddc0f 100644
--- a/src/shrpx_connection_handler.cc
+++ b/src/shrpx_connection_handler.cc
@@ -358,7 +358,8 @@ void ConnectionHandler::graceful_shutdown_worker() {
 int ConnectionHandler::handle_connection(int fd, sockaddr *addr, int addrlen,
                                          const UpstreamAddr *faddr) {
   if (LOG_ENABLED(INFO)) {
-    LLOG(INFO, this) << "Accepted connection. fd=" << fd;
+    LLOG(INFO, this) << "Accepted connection from "
+                     << util::numeric_name(addr, addrlen) << ", fd=" << fd;
   }
 
   if (get_config()->num_worker == 1) {
diff --git a/src/shrpx_downstream.cc b/src/shrpx_downstream.cc
index b30cab74..27cb8a18 100644
--- a/src/shrpx_downstream.cc
+++ b/src/shrpx_downstream.cc
@@ -137,7 +137,8 @@ Downstream::Downstream(Upstream *upstream, MemchunkPool *mcpool,
       chunked_request_(false),
       chunked_response_(false),
       expect_final_response_(false),
-      request_pending_(false) {
+      request_pending_(false),
+      request_header_sent_(false) {
 
   auto &timeoutconf = get_config()->http2.timeout;
 
@@ -885,7 +886,7 @@ bool Downstream::accesslog_ready() const { return resp_.http_status > 0; }
 
 void Downstream::add_retry() { ++num_retry_; }
 
-bool Downstream::no_more_retry() const { return num_retry_ > 5; }
+bool Downstream::no_more_retry() const { return num_retry_ > 50; }
 
 void Downstream::set_request_downstream_host(const StringRef &host) {
   request_downstream_host_ = host;
@@ -895,10 +896,13 @@ void Downstream::set_request_pending(bool f) { request_pending_ = f; }
 
 bool Downstream::get_request_pending() const { return request_pending_; }
 
+void Downstream::set_request_header_sent(bool f) { request_header_sent_ = f; }
+
 bool Downstream::request_submission_ready() const {
   return (request_state_ == Downstream::HEADER_COMPLETE ||
           request_state_ == Downstream::MSG_COMPLETE) &&
-         request_pending_ && response_state_ == Downstream::INITIAL;
+         (request_pending_ || !request_header_sent_) &&
+         response_state_ == Downstream::INITIAL;
 }
 
 int Downstream::get_dispatch_state() const { return dispatch_state_; }
diff --git a/src/shrpx_downstream.h b/src/shrpx_downstream.h
index 8ae62847..d5514ea8 100644
--- a/src/shrpx_downstream.h
+++ b/src/shrpx_downstream.h
@@ -302,7 +302,11 @@ public:
   DefaultMemchunks *get_request_buf();
   void set_request_pending(bool f);
   bool get_request_pending() const;
+  void set_request_header_sent(bool f);
   // Returns true if request is ready to be submitted to downstream.
+  // When sending pending request, get_request_pending() should be
+  // checked too because this function may return true when
+  // get_request_pending() returns false.
   bool request_submission_ready() const;
 
   // downstream response API
@@ -471,6 +475,8 @@ private:
   // has not been established or should be checked before use;
   // currently used only with HTTP/2 connection.
   bool request_pending_;
+  // true if downstream request header is considered to be sent.
+  bool request_header_sent_;
 };
 
 } // namespace shrpx
diff --git a/src/shrpx_http2_downstream_connection.cc b/src/shrpx_http2_downstream_connection.cc
index fb601f43..2a85f980 100644
--- a/src/shrpx_http2_downstream_connection.cc
+++ b/src/shrpx_http2_downstream_connection.cc
@@ -117,11 +117,11 @@ void Http2DownstreamConnection::detach_downstream(Downstream *downstream) {
 
   auto &resp = downstream_->response();
 
-  if (submit_rst_stream(downstream) == 0) {
-    http2session_->signal_write();
-  }
-
   if (downstream_->get_downstream_stream_id() != -1) {
+    if (submit_rst_stream(downstream) == 0) {
+      http2session_->signal_write();
+    }
+
     http2session_->consume(downstream_->get_downstream_stream_id(),
                            resp.unconsumed_body_length);
 
diff --git a/src/shrpx_http2_session.cc b/src/shrpx_http2_session.cc
index e8650c02..721fd5b7 100644
--- a/src/shrpx_http2_session.cc
+++ b/src/shrpx_http2_session.cc
@@ -264,25 +264,28 @@ int Http2Session::disconnect(bool hard) {
   state_ = DISCONNECTED;
 
   // When deleting Http2DownstreamConnection, it calls this object's
-  // remove_downstream_connection(). The multiple
+  // remove_downstream_connection().  The multiple
   // Http2DownstreamConnection objects belong to the same
-  // ClientHandler object.  So first dump ClientHandler objects.
+  // ClientHandler object if upstream is h2 or SPDY.  So be careful
+  // when you delete ClientHandler here.
   //
   // We allow creating new pending Http2DownstreamConnection with this
   // object.  Upstream::on_downstream_reset() may add
-  // Http2DownstreamConnection.
+  // Http2DownstreamConnection to another Http2Session.
 
-  std::set<ClientHandler *> handlers;
-  for (auto dc = dconns_.head; dc; dc = dc->dlnext) {
-    if (!dc->get_client_handler()) {
-      continue;
-    }
-    handlers.insert(dc->get_client_handler());
-  }
-  for (auto h : handlers) {
-    if (h->get_upstream()->on_downstream_reset(hard) != 0) {
-      delete h;
+  for (auto dc = dconns_.head; dc;) {
+    auto next = dc->dlnext;
+    auto downstream = dc->get_downstream();
+    auto upstream = downstream->get_upstream();
+
+    // Failure is allowed only for HTTP/1 upstream where upstream is
+    // not shared by multiple Downstreams.
+    if (upstream->on_downstream_reset(downstream, hard) != 0) {
+      delete upstream->get_client_handler();
     }
+
+    // dc was deleted
+    dc = next;
   }
 
   auto streams = std::move(streams_);
@@ -734,46 +737,44 @@ int on_stream_close_callback(nghttp2_session *session, int32_t stream_id,
   auto dconn = sd->dconn;
   if (dconn) {
     auto downstream = dconn->get_downstream();
-    if (downstream && downstream->get_downstream_stream_id() == stream_id) {
-      auto upstream = downstream->get_upstream();
+    auto upstream = downstream->get_upstream();
 
-      if (downstream->get_downstream_stream_id() % 2 == 0 &&
-          downstream->get_request_state() == Downstream::INITIAL) {
-        // Downstream is canceled in backend before it is submitted in
-        // frontend session.
+    if (downstream->get_downstream_stream_id() % 2 == 0 &&
+        downstream->get_request_state() == Downstream::INITIAL) {
+      // Downstream is canceled in backend before it is submitted in
+      // frontend session.
 
-        // This will avoid to send RST_STREAM to backend
-        downstream->set_response_state(Downstream::MSG_RESET);
-        upstream->cancel_premature_downstream(downstream);
-      } else {
-        if (downstream->get_upgraded() &&
-            downstream->get_response_state() == Downstream::HEADER_COMPLETE) {
-          // For tunneled connection, we have to submit RST_STREAM to
-          // upstream *after* whole response body is sent. We just set
-          // MSG_COMPLETE here. Upstream will take care of that.
-          downstream->get_upstream()->on_downstream_body_complete(downstream);
-          downstream->set_response_state(Downstream::MSG_COMPLETE);
-        } else if (error_code == NGHTTP2_NO_ERROR) {
-          switch (downstream->get_response_state()) {
-          case Downstream::MSG_COMPLETE:
-          case Downstream::MSG_BAD_HEADER:
-            break;
-          default:
-            downstream->set_response_state(Downstream::MSG_RESET);
-          }
-        } else if (downstream->get_response_state() !=
-                   Downstream::MSG_BAD_HEADER) {
+      // This will avoid to send RST_STREAM to backend
+      downstream->set_response_state(Downstream::MSG_RESET);
+      upstream->cancel_premature_downstream(downstream);
+    } else {
+      if (downstream->get_upgraded() &&
+          downstream->get_response_state() == Downstream::HEADER_COMPLETE) {
+        // For tunneled connection, we have to submit RST_STREAM to
+        // upstream *after* whole response body is sent. We just set
+        // MSG_COMPLETE here. Upstream will take care of that.
+        downstream->get_upstream()->on_downstream_body_complete(downstream);
+        downstream->set_response_state(Downstream::MSG_COMPLETE);
+      } else if (error_code == NGHTTP2_NO_ERROR) {
+        switch (downstream->get_response_state()) {
+        case Downstream::MSG_COMPLETE:
+        case Downstream::MSG_BAD_HEADER:
+          break;
+        default:
           downstream->set_response_state(Downstream::MSG_RESET);
         }
-        if (downstream->get_response_state() == Downstream::MSG_RESET &&
-            downstream->get_response_rst_stream_error_code() ==
-                NGHTTP2_NO_ERROR) {
-          downstream->set_response_rst_stream_error_code(error_code);
-        }
-        call_downstream_readcb(http2session, downstream);
+      } else if (downstream->get_response_state() !=
+                 Downstream::MSG_BAD_HEADER) {
+        downstream->set_response_state(Downstream::MSG_RESET);
       }
-      // dconn may be deleted
+      if (downstream->get_response_state() == Downstream::MSG_RESET &&
+          downstream->get_response_rst_stream_error_code() ==
+              NGHTTP2_NO_ERROR) {
+        downstream->set_response_rst_stream_error_code(error_code);
+      }
+      call_downstream_readcb(http2session, downstream);
     }
+    // dconn may be deleted
   }
   // The life time of StreamData ends here
   http2session->remove_stream_data(sd);
@@ -803,9 +804,6 @@ int on_header_callback2(nghttp2_session *session, const nghttp2_frame *frame,
     return 0;
   }
   auto downstream = sd->dconn->get_downstream();
-  if (!downstream) {
-    return 0;
-  }
 
   auto namebuf = nghttp2_rcbuf_get_buf(name);
   auto valuebuf = nghttp2_rcbuf_get_buf(value);
@@ -915,10 +913,6 @@ int on_invalid_header_callback2(nghttp2_session *session,
   if (!sd || !sd->dconn) {
     return 0;
   }
-  auto downstream = sd->dconn->get_downstream();
-  if (!downstream) {
-    return 0;
-  }
 
   int32_t stream_id;
 
@@ -963,13 +957,6 @@ int on_begin_headers_callback(nghttp2_session *session,
                                       NGHTTP2_INTERNAL_ERROR);
       return 0;
     }
-    auto downstream = sd->dconn->get_downstream();
-    if (!downstream ||
-        downstream->get_downstream_stream_id() != frame->hd.stream_id) {
-      http2session->submit_rst_stream(frame->hd.stream_id,
-                                      NGHTTP2_INTERNAL_ERROR);
-      return 0;
-    }
     return 0;
   }
   case NGHTTP2_PUSH_PROMISE: {
@@ -1130,11 +1117,6 @@ int on_frame_recv_callback(nghttp2_session *session, const nghttp2_frame *frame,
       return 0;
     }
     auto downstream = sd->dconn->get_downstream();
-    if (!downstream ||
-        downstream->get_downstream_stream_id() != frame->hd.stream_id) {
-      return 0;
-    }
-
     auto upstream = downstream->get_upstream();
     rv = upstream->on_downstream_body(downstream, nullptr, 0, true);
     if (rv != 0) {
@@ -1169,10 +1151,6 @@ int on_frame_recv_callback(nghttp2_session *session, const nghttp2_frame *frame,
     }
     auto downstream = sd->dconn->get_downstream();
 
-    if (!downstream) {
-      return 0;
-    }
-
     if (frame->headers.cat == NGHTTP2_HCAT_RESPONSE ||
         frame->headers.cat == NGHTTP2_HCAT_PUSH_RESPONSE) {
       rv = on_response_headers(http2session, downstream, session, frame);
@@ -1218,13 +1196,9 @@ int on_frame_recv_callback(nghttp2_session *session, const nghttp2_frame *frame,
         nghttp2_session_get_stream_user_data(session, frame->hd.stream_id));
     if (sd && sd->dconn) {
       auto downstream = sd->dconn->get_downstream();
-      if (downstream &&
-          downstream->get_downstream_stream_id() == frame->hd.stream_id) {
-
-        downstream->set_response_rst_stream_error_code(
-            frame->rst_stream.error_code);
-        call_downstream_readcb(http2session, downstream);
-      }
+      downstream->set_response_rst_stream_error_code(
+          frame->rst_stream.error_code);
+      call_downstream_readcb(http2session, downstream);
     }
     return 0;
   }
@@ -1326,9 +1300,7 @@ int on_data_chunk_recv_callback(nghttp2_session *session, uint8_t flags,
     return 0;
   }
   auto downstream = sd->dconn->get_downstream();
-  if (!downstream || downstream->get_downstream_stream_id() != stream_id ||
-      !downstream->expect_response_body()) {
-
+  if (!downstream->expect_response_body()) {
     http2session->submit_rst_stream(stream_id, NGHTTP2_INTERNAL_ERROR);
 
     if (http2session->consume(stream_id, len) != 0) {
@@ -1380,10 +1352,6 @@ int on_frame_send_callback(nghttp2_session *session, const nghttp2_frame *frame,
   auto http2session = static_cast<Http2Session *>(user_data);
 
   if (frame->hd.type == NGHTTP2_DATA || frame->hd.type == NGHTTP2_HEADERS) {
-    if ((frame->hd.flags & NGHTTP2_FLAG_END_STREAM) == 0) {
-      return 0;
-    }
-
     auto sd = static_cast<StreamData *>(
         nghttp2_session_get_stream_user_data(session, frame->hd.stream_id));
 
@@ -1393,8 +1361,12 @@ int on_frame_send_callback(nghttp2_session *session, const nghttp2_frame *frame,
 
     auto downstream = sd->dconn->get_downstream();
 
-    if (!downstream ||
-        downstream->get_downstream_stream_id() != frame->hd.stream_id) {
+    if (frame->hd.type == NGHTTP2_HEADERS &&
+        frame->headers.cat == NGHTTP2_HCAT_REQUEST) {
+      downstream->set_request_header_sent(true);
+    }
+
+    if ((frame->hd.flags & NGHTTP2_FLAG_END_STREAM) == 0) {
       return 0;
     }
 
@@ -1419,29 +1391,42 @@ int on_frame_not_send_callback(nghttp2_session *session,
   if (LOG_ENABLED(INFO)) {
     SSLOG(INFO, http2session) << "Failed to send control frame type="
                               << static_cast<uint32_t>(frame->hd.type)
-                              << "lib_error_code=" << lib_error_code << ":"
+                              << ", lib_error_code=" << lib_error_code << ": "
                               << nghttp2_strerror(lib_error_code);
   }
-  if (frame->hd.type == NGHTTP2_HEADERS &&
-      lib_error_code != NGHTTP2_ERR_STREAM_CLOSED &&
-      lib_error_code != NGHTTP2_ERR_STREAM_CLOSING) {
-    // To avoid stream hanging around, flag Downstream::MSG_RESET.
-    auto sd = static_cast<StreamData *>(
-        nghttp2_session_get_stream_user_data(session, frame->hd.stream_id));
-    if (!sd) {
-      return 0;
-    }
-    if (!sd->dconn) {
-      return 0;
-    }
-    auto downstream = sd->dconn->get_downstream();
-    if (!downstream ||
-        downstream->get_downstream_stream_id() != frame->hd.stream_id) {
-      return 0;
-    }
-    downstream->set_response_state(Downstream::MSG_RESET);
-    call_downstream_readcb(http2session, downstream);
+  if (frame->hd.type != NGHTTP2_HEADERS ||
+      lib_error_code == NGHTTP2_ERR_STREAM_CLOSED ||
+      lib_error_code == NGHTTP2_ERR_STREAM_CLOSING) {
+    return 0;
   }
+
+  auto sd = static_cast<StreamData *>(
+      nghttp2_session_get_stream_user_data(session, frame->hd.stream_id));
+  if (!sd) {
+    return 0;
+  }
+  if (!sd->dconn) {
+    return 0;
+  }
+  auto downstream = sd->dconn->get_downstream();
+
+  if (lib_error_code == NGHTTP2_ERR_START_STREAM_NOT_ALLOWED) {
+    // Migrate to another downstream connection.
+    auto upstream = downstream->get_upstream();
+
+    if (upstream->on_downstream_reset(downstream, false)) {
+      // This should be done for h1 upstream only.  Deleting
+      // ClientHandler for h2 or SPDY upstream may lead to crash.
+      delete upstream->get_client_handler();
+    }
+
+    return 0;
+  }
+
+  // To avoid stream hanging around, flag Downstream::MSG_RESET.
+  downstream->set_response_state(Downstream::MSG_RESET);
+  call_downstream_readcb(http2session, downstream);
+
   return 0;
 }
 } // namespace
@@ -1819,7 +1804,8 @@ void Http2Session::submit_pending_requests() {
   for (auto dconn = dconns_.head; dconn; dconn = dconn->dlnext) {
     auto downstream = dconn->get_downstream();
 
-    if (!downstream || !downstream->request_submission_ready()) {
+    if (!downstream->get_request_pending() ||
+        !downstream->request_submission_ready()) {
       continue;
     }
 
@@ -2157,6 +2143,7 @@ int Http2Session::handle_downstream_push_promise_complete(
   auto upstream = promised_downstream->get_upstream();
 
   promised_downstream->set_request_state(Downstream::MSG_COMPLETE);
+  promised_downstream->set_request_header_sent(true);
 
   if (upstream->on_downstream_push_promise_complete(downstream,
                                                     promised_downstream) != 0) {
diff --git a/src/shrpx_http2_upstream.cc b/src/shrpx_http2_upstream.cc
index 34881254..2d7e2876 100644
--- a/src/shrpx_http2_upstream.cc
+++ b/src/shrpx_http2_upstream.cc
@@ -1821,64 +1821,66 @@ void Http2Upstream::on_handler_delete() {
   }
 }
 
-int Http2Upstream::on_downstream_reset(bool no_retry) {
+int Http2Upstream::on_downstream_reset(Downstream *downstream, bool no_retry) {
   int rv;
 
-  for (auto downstream = downstream_queue_.get_downstreams(); downstream;
-       downstream = downstream->dlnext) {
-    if (downstream->get_dispatch_state() != Downstream::DISPATCH_ACTIVE) {
-      // This is error condition when we failed push_request_headers()
-      // in initiate_downstream().  Otherwise, we have
-      // Downstream::DISPATCH_ACTIVE state, or we did not set
-      // DownstreamConnection.
-      downstream->pop_downstream_connection();
-      continue;
-    }
-
-    if (!downstream->request_submission_ready()) {
-      // pushed stream is handled here
-      rst_stream(downstream, NGHTTP2_INTERNAL_ERROR);
-      downstream->pop_downstream_connection();
-      continue;
-    }
-
+  if (downstream->get_dispatch_state() != Downstream::DISPATCH_ACTIVE) {
+    // This is error condition when we failed push_request_headers()
+    // in initiate_downstream().  Otherwise, we have
+    // Downstream::DISPATCH_ACTIVE state, or we did not set
+    // DownstreamConnection.
     downstream->pop_downstream_connection();
+    handler_->signal_write();
 
-    downstream->add_retry();
-
-    std::unique_ptr<DownstreamConnection> dconn;
-
-    if (no_retry || downstream->no_more_retry()) {
-      goto fail;
-    }
-
-    // downstream connection is clean; we can retry with new
-    // downstream connection.
-
-    dconn = handler_->get_downstream_connection(downstream);
-    if (!dconn) {
-      goto fail;
-    }
-
-    rv = downstream->attach_downstream_connection(std::move(dconn));
-    if (rv != 0) {
-      goto fail;
-    }
-
-    rv = downstream->push_request_headers();
-    if (rv != 0) {
-      goto fail;
-    }
-
-    continue;
-
-  fail:
-    if (on_downstream_abort_request(downstream, 503) != 0) {
-      return -1;
-    }
-    downstream->pop_downstream_connection();
+    return 0;
   }
 
+  if (!downstream->request_submission_ready()) {
+    // pushed stream is handled here
+    rst_stream(downstream, NGHTTP2_INTERNAL_ERROR);
+    downstream->pop_downstream_connection();
+
+    handler_->signal_write();
+
+    return 0;
+  }
+
+  downstream->pop_downstream_connection();
+
+  downstream->add_retry();
+
+  std::unique_ptr<DownstreamConnection> dconn;
+
+  if (no_retry || downstream->no_more_retry()) {
+    goto fail;
+  }
+
+  // downstream connection is clean; we can retry with new
+  // downstream connection.
+
+  dconn = handler_->get_downstream_connection(downstream);
+  if (!dconn) {
+    goto fail;
+  }
+
+  rv = downstream->attach_downstream_connection(std::move(dconn));
+  if (rv != 0) {
+    goto fail;
+  }
+
+  rv = downstream->push_request_headers();
+  if (rv != 0) {
+    goto fail;
+  }
+
+  return 0;
+
+fail:
+  if (on_downstream_abort_request(downstream, 503) != 0) {
+    rst_stream(downstream, NGHTTP2_INTERNAL_ERROR);
+  }
+  downstream->pop_downstream_connection();
+
   handler_->signal_write();
 
   return 0;
diff --git a/src/shrpx_http2_upstream.h b/src/shrpx_http2_upstream.h
index f9c8fb82..84cdea0c 100644
--- a/src/shrpx_http2_upstream.h
+++ b/src/shrpx_http2_upstream.h
@@ -78,7 +78,7 @@ public:
   virtual int on_downstream_body_complete(Downstream *downstream);
 
   virtual void on_handler_delete();
-  virtual int on_downstream_reset(bool no_retry);
+  virtual int on_downstream_reset(Downstream *downstream, bool no_retry);
   virtual int send_reply(Downstream *downstream, const uint8_t *body,
                          size_t bodylen);
   virtual int initiate_push(Downstream *downstream, const StringRef &uri);
diff --git a/src/shrpx_http_downstream_connection.cc b/src/shrpx_http_downstream_connection.cc
index 65e2cb37..9a454a21 100644
--- a/src/shrpx_http_downstream_connection.cc
+++ b/src/shrpx_http_downstream_connection.cc
@@ -344,6 +344,10 @@ int HttpDownstreamConnection::push_request_headers() {
 
   auto &httpconf = get_config()->http;
 
+  // Set request_sent to true because we write request into buffer
+  // here.
+  downstream_->set_request_header_sent(true);
+
   // For HTTP/1.0 request, there is no authority in request.  In that
   // case, we use backend server's host nonetheless.
   auto authority = StringRef(downstream_hostport);
diff --git a/src/shrpx_https_upstream.cc b/src/shrpx_https_upstream.cc
index 6332b29f..0be62b62 100644
--- a/src/shrpx_https_upstream.cc
+++ b/src/shrpx_https_upstream.cc
@@ -1202,10 +1202,12 @@ void HttpsUpstream::on_handler_delete() {
   }
 }
 
-int HttpsUpstream::on_downstream_reset(bool no_retry) {
+int HttpsUpstream::on_downstream_reset(Downstream *downstream, bool no_retry) {
   int rv;
   std::unique_ptr<DownstreamConnection> dconn;
 
+  assert(downstream == downstream_.get());
+
   if (!downstream_->request_submission_ready()) {
     // Return error so that caller can delete handler
     return -1;
diff --git a/src/shrpx_https_upstream.h b/src/shrpx_https_upstream.h
index 0f9b8dd0..4544651c 100644
--- a/src/shrpx_https_upstream.h
+++ b/src/shrpx_https_upstream.h
@@ -73,7 +73,7 @@ public:
   virtual int on_downstream_body_complete(Downstream *downstream);
 
   virtual void on_handler_delete();
-  virtual int on_downstream_reset(bool no_retry);
+  virtual int on_downstream_reset(Downstream *downstream, bool no_retry);
   virtual int send_reply(Downstream *downstream, const uint8_t *body,
                          size_t bodylen);
   virtual int initiate_push(Downstream *downstream, const StringRef &uri);
diff --git a/src/shrpx_spdy_upstream.cc b/src/shrpx_spdy_upstream.cc
index 7b17c4c2..8077d426 100644
--- a/src/shrpx_spdy_upstream.cc
+++ b/src/shrpx_spdy_upstream.cc
@@ -1287,63 +1287,66 @@ void SpdyUpstream::on_handler_delete() {
   }
 }
 
-int SpdyUpstream::on_downstream_reset(bool no_retry) {
+int SpdyUpstream::on_downstream_reset(Downstream *downstream, bool no_retry) {
   int rv;
 
-  for (auto downstream = downstream_queue_.get_downstreams(); downstream;
-       downstream = downstream->dlnext) {
-    if (downstream->get_dispatch_state() != Downstream::DISPATCH_ACTIVE) {
-      // This is error condition when we failed push_request_headers()
-      // in initiate_downstream().  Otherwise, we have
-      // Downstream::DISPATCH_ACTIVE state, or we did not set
-      // DownstreamConnection.
-      downstream->pop_downstream_connection();
-      continue;
-    }
-
-    if (!downstream->request_submission_ready()) {
-      rst_stream(downstream, SPDYLAY_INTERNAL_ERROR);
-      downstream->pop_downstream_connection();
-      continue;
-    }
-
+  if (downstream->get_dispatch_state() != Downstream::DISPATCH_ACTIVE) {
+    // This is error condition when we failed push_request_headers()
+    // in initiate_downstream().  Otherwise, we have
+    // Downstream::DISPATCH_ACTIVE state, or we did not set
+    // DownstreamConnection.
     downstream->pop_downstream_connection();
 
-    downstream->add_retry();
+    handler_->signal_write();
 
-    std::unique_ptr<DownstreamConnection> dconn;
-
-    if (no_retry || downstream->no_more_retry()) {
-      goto fail;
-    }
-
-    // downstream connection is clean; we can retry with new
-    // downstream connection.
-
-    dconn = handler_->get_downstream_connection(downstream);
-    if (!dconn) {
-      goto fail;
-    }
-
-    rv = downstream->attach_downstream_connection(std::move(dconn));
-    if (rv != 0) {
-      goto fail;
-    }
-
-    rv = downstream->push_request_headers();
-    if (rv != 0) {
-      goto fail;
-    }
-
-    continue;
-
-  fail:
-    if (on_downstream_abort_request(downstream, 503) != 0) {
-      return -1;
-    }
-    downstream->pop_downstream_connection();
+    return 0;
   }
 
+  if (!downstream->request_submission_ready()) {
+    rst_stream(downstream, SPDYLAY_INTERNAL_ERROR);
+    downstream->pop_downstream_connection();
+
+    handler_->signal_write();
+
+    return 0;
+  }
+
+  downstream->pop_downstream_connection();
+
+  downstream->add_retry();
+
+  std::unique_ptr<DownstreamConnection> dconn;
+
+  if (no_retry || downstream->no_more_retry()) {
+    goto fail;
+  }
+
+  // downstream connection is clean; we can retry with new
+  // downstream connection.
+
+  dconn = handler_->get_downstream_connection(downstream);
+  if (!dconn) {
+    goto fail;
+  }
+
+  rv = downstream->attach_downstream_connection(std::move(dconn));
+  if (rv != 0) {
+    goto fail;
+  }
+
+  rv = downstream->push_request_headers();
+  if (rv != 0) {
+    goto fail;
+  }
+
+  return 0;
+
+fail:
+  if (on_downstream_abort_request(downstream, 503) != 0) {
+    rst_stream(downstream, SPDYLAY_INTERNAL_ERROR);
+  }
+  downstream->pop_downstream_connection();
+
   handler_->signal_write();
 
   return 0;
diff --git a/src/shrpx_spdy_upstream.h b/src/shrpx_spdy_upstream.h
index 2d6bd244..af5f589a 100644
--- a/src/shrpx_spdy_upstream.h
+++ b/src/shrpx_spdy_upstream.h
@@ -72,7 +72,7 @@ public:
   virtual int on_downstream_body_complete(Downstream *downstream);
 
   virtual void on_handler_delete();
-  virtual int on_downstream_reset(bool no_retry);
+  virtual int on_downstream_reset(Downstream *downstream, bool no_retry);
 
   virtual int send_reply(Downstream *downstream, const uint8_t *body,
                          size_t bodylen);
diff --git a/src/shrpx_upstream.h b/src/shrpx_upstream.h
index f85bb776..bc013aa1 100644
--- a/src/shrpx_upstream.h
+++ b/src/shrpx_upstream.h
@@ -57,10 +57,11 @@ public:
   virtual int on_downstream_body_complete(Downstream *downstream) = 0;
 
   virtual void on_handler_delete() = 0;
-  // Called when downstream connection is reset.  Currently this is
-  // only used by Http2Session.  If |no_retry| is true, another
-  // connection attempt using new DownstreamConnection is not allowed.
-  virtual int on_downstream_reset(bool no_retry) = 0;
+  // Called when downstream connection for |downstream| is reset.
+  // Currently this is only used by Http2Session.  If |no_retry| is
+  // true, another connection attempt using new DownstreamConnection
+  // is not allowed.
+  virtual int on_downstream_reset(Downstream *downstream, bool no_retry) = 0;
 
   virtual void pause_read(IOCtrlReason reason) = 0;
   virtual int resume_read(IOCtrlReason reason, Downstream *downstream,