diff --git a/modules/http2/h2_session.c b/modules/http2/h2_session.c

index 805d677..a1b31d2 100644

--- a/modules/http2/h2_session.c

+++ b/modules/http2/h2_session.c

@@ -235,6 +235,7 @@ static int on_data_chunk_recv_cb(nghttp2_session *ngh2, uint8_t flags,

     stream = h2_session_stream_get(session, stream_id);

     if (stream) {

         status = h2_stream_recv_DATA(stream, flags, data, len);

+        dispatch_event(session, H2_SESSION_EV_STREAM_CHANGE, 0, "stream data rcvd");

     }

     else {

         ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, session->c, APLOGNO(03064)

@@ -317,9 +318,9 @@ static int on_header_cb(nghttp2_session *ngh2, const nghttp2_frame *frame,

 }

 /**

- * nghttp2 session has received a complete frame. Most, it uses

- * for processing of internal state. HEADER and DATA frames however

- * we need to handle ourself.

+ * nghttp2 session has received a complete frame. Most are used by nghttp2

+ * for processing of internal state. Some, like HEADER and DATA frames,

+ * we need to act on.

  */

 static int on_frame_recv_cb(nghttp2_session *ng2s,

                             const nghttp2_frame *frame,

@@ -378,6 +379,9 @@ static int on_frame_recv_cb(nghttp2_session *ng2s,

                           "h2_stream(%ld-%d): WINDOW_UPDATE incr=%d", 

                           session->id, (int)frame->hd.stream_id,

                           frame->window_update.window_size_increment);

+            if (nghttp2_session_want_write(session->ngh2)) {

+                dispatch_event(session, H2_SESSION_EV_FRAME_RCVD, 0, "window update");

+            }

             break;

         case NGHTTP2_RST_STREAM:

             ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, session->c, APLOGNO(03067)

@@ -404,6 +408,12 @@ static int on_frame_recv_cb(nghttp2_session *ng2s,

                                frame->goaway.error_code, NULL);

             }

             break;

+        case NGHTTP2_SETTINGS:

+            if (APLOGctrace2(session->c)) {

+                ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, session->c,

+                              H2_SSSN_MSG(session, "SETTINGS, len=%ld"), (long)frame->hd.length);

+            }

+            break;

         default:

             if (APLOGctrace2(session->c)) {

                 char buffer[256];

@@ -415,7 +425,40 @@ static int on_frame_recv_cb(nghttp2_session *ng2s,

             }

             break;

     }

-    return (APR_SUCCESS == rv)? 0 : NGHTTP2_ERR_PROTO;

+    

+    if (session->state == H2_SESSION_ST_IDLE) {

+        /* We received a frame, but session is in state IDLE. That means the frame

+         * did not really progress any of the (possibly) open streams. It was a meta

+         * frame, e.g. SETTINGS/WINDOW_UPDATE/unknown/etc.

+         * Remember: IDLE means we cannot send because either there are no streams open or

+         * all open streams are blocked on exhausted WINDOWs for outgoing data.

+         * The more frames we receive that do not change this, the less interested we

+         * become in serving this connection. This is expressed in increasing "idle_delays".

+         * Eventually, the connection will timeout and we'll close it. */

+        session->idle_frames = H2MIN(session->idle_frames + 1, session->frames_received);

+            ap_log_cerror( APLOG_MARK, APLOG_TRACE2, 0, session->c,

+                          H2_SSSN_MSG(session, "session has %ld idle frames"), 

+                          (long)session->idle_frames);

+        if (session->idle_frames > 10) {

+            apr_size_t busy_frames = H2MAX(session->frames_received - session->idle_frames, 1);

+            int idle_ratio = (int)(session->idle_frames / busy_frames); 

+            if (idle_ratio > 100) {

+                session->idle_delay = apr_time_from_msec(H2MIN(1000, idle_ratio));

+            }

+            else if (idle_ratio > 10) {

+                session->idle_delay = apr_time_from_msec(10);

+            }

+            else if (idle_ratio > 1) {

+                session->idle_delay = apr_time_from_msec(1);

+            }

+            else {

+                session->idle_delay = 0;

+            }

+        }

+    }

+    

+    if (APR_SUCCESS != rv) return NGHTTP2_ERR_PROTO;

+    return 0;

 }

 static int h2_session_continue_data(h2_session *session) {

@@ -1603,23 +1646,57 @@ static void update_child_status(h2_session *session, int status, const char *msg

 static void transit(h2_session *session, const char *action, h2_session_state nstate)

 {

+    apr_time_t timeout;

+    int ostate, loglvl;

+    const char *s;

+    

     if (session->state != nstate) {

-        int loglvl = APLOG_DEBUG;

-        if ((session->state == H2_SESSION_ST_BUSY && nstate == H2_SESSION_ST_WAIT)

-            || (session->state == H2_SESSION_ST_WAIT && nstate == H2_SESSION_ST_BUSY)){

+        ostate = session->state;

+        session->state = nstate;

+        

+        loglvl = APLOG_DEBUG;

+        if ((ostate == H2_SESSION_ST_BUSY && nstate == H2_SESSION_ST_WAIT)

+            || (ostate == H2_SESSION_ST_WAIT && nstate == H2_SESSION_ST_BUSY)){

             loglvl = APLOG_TRACE1;

         }

         ap_log_cerror(APLOG_MARK, loglvl, 0, session->c, 

                       H2_SSSN_LOG(APLOGNO(03078), session, 

                       "transit [%s] -- %s --> [%s]"), 

-                      h2_session_state_str(session->state), action, 

+                      h2_session_state_str(ostate), action, 

                       h2_session_state_str(nstate));

-        session->state = nstate;

+        

         switch (session->state) {

             case H2_SESSION_ST_IDLE:

-                update_child_status(session, (session->open_streams == 0? 

-                                              SERVER_BUSY_KEEPALIVE

-                                              : SERVER_BUSY_READ), "idle");

+                if (!session->remote.emitted_count) {

+                    /* on fresh connections, with async mpm, do not return

+                     * to mpm for a second. This gives the first request a better

+                     * chance to arrive (und connection leaving IDLE state).

+                     * If we return to mpm right away, this connection has the

+                     * same chance of being cleaned up by the mpm as connections

+                     * that already served requests - not fair. */

+                    session->idle_sync_until = apr_time_now() + apr_time_from_sec(1);

+                    s = "timeout";

+                    timeout = H2MAX(session->s->timeout, session->s->keep_alive_timeout);

+                    update_child_status(session, SERVER_BUSY_READ, "idle");

+                    ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, session->c, 

+                                  H2_SSSN_LOG("", session, "enter idle, timeout = %d sec"), 

+                                  (int)apr_time_sec(H2MAX(session->s->timeout, session->s->keep_alive_timeout)));

+                }

+                else if (session->open_streams) {

+                    s = "timeout";

+                    timeout = session->s->keep_alive_timeout;

+                    update_child_status(session, SERVER_BUSY_KEEPALIVE, "idle");

+                }

+                else {

+                    /* normal keepalive setup */

+                    s = "keepalive";

+                    timeout = session->s->keep_alive_timeout;

+                    update_child_status(session, SERVER_BUSY_KEEPALIVE, "idle");

+                }

+                session->idle_until = apr_time_now() + timeout; 

+                ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, session->c, 

+                              H2_SSSN_LOG("", session, "enter idle, %s = %d sec"), 

+                              s, (int)apr_time_sec(timeout));

                 break;

             case H2_SESSION_ST_DONE:

                 update_child_status(session, SERVER_CLOSING, "done");

@@ -1726,8 +1803,6 @@ static void h2_session_ev_no_io(h2_session *session, int arg, const char *msg)

                      * This means we only wait for WINDOW_UPDATE from the 

                      * client and can block on READ. */

                     transit(session, "no io (flow wait)", H2_SESSION_ST_IDLE);

-                    session->idle_until = apr_time_now() + session->s->timeout;

-                    session->keep_sync_until = session->idle_until;

                     /* Make sure we have flushed all previously written output

                      * so that the client will react. */

                     if (h2_conn_io_flush(&session->io) != APR_SUCCESS) {

@@ -1738,12 +1813,7 @@ static void h2_session_ev_no_io(h2_session *session, int arg, const char *msg)

             }

             else if (session->local.accepting) {

                 /* When we have no streams, but accept new, switch to idle */

-                apr_time_t now = apr_time_now();

                 transit(session, "no io (keepalive)", H2_SESSION_ST_IDLE);

-                session->idle_until = (session->remote.emitted_count? 

-                                       session->s->keep_alive_timeout : 

-                                       session->s->timeout) + now;

-                session->keep_sync_until = now + apr_time_from_sec(1);

             }

             else {

                 /* We are no longer accepting new streams and there are

@@ -1758,12 +1828,25 @@ static void h2_session_ev_no_io(h2_session *session, int arg, const char *msg)

     }

 }

-static void h2_session_ev_data_read(h2_session *session, int arg, const char *msg)

+static void h2_session_ev_frame_rcvd(h2_session *session, int arg, const char *msg)

+{

+    switch (session->state) {

+        case H2_SESSION_ST_IDLE:

+        case H2_SESSION_ST_WAIT:

+            transit(session, "frame received", H2_SESSION_ST_BUSY);

+            break;

+        default:

+            /* nop */

+            break;

+    }

+}

+

+static void h2_session_ev_stream_change(h2_session *session, int arg, const char *msg)

 {

     switch (session->state) {

         case H2_SESSION_ST_IDLE:

         case H2_SESSION_ST_WAIT:

-            transit(session, "data read", H2_SESSION_ST_BUSY);

+            transit(session, "stream change", H2_SESSION_ST_BUSY);

             break;

         default:

             /* nop */

@@ -1803,16 +1886,6 @@ static void h2_session_ev_pre_close(h2_session *session, int arg, const char *ms

 static void ev_stream_open(h2_session *session, h2_stream *stream)

 {

     h2_iq_append(session->in_process, stream->id);

-    switch (session->state) {

-        case H2_SESSION_ST_IDLE:

-            if (session->open_streams == 1) {

-                /* enter timeout, since we have a stream again */

-                session->idle_until = (session->s->timeout + apr_time_now());

-            }

-            break;

-        default:

-            break;

-    }

 }

 static void ev_stream_closed(h2_session *session, h2_stream *stream)

@@ -1825,11 +1898,6 @@ static void ev_stream_closed(h2_session *session, h2_stream *stream)

     }

     switch (session->state) {

         case H2_SESSION_ST_IDLE:

-            if (session->open_streams == 0) {

-                /* enter keepalive timeout, since we no longer have streams */

-                session->idle_until = (session->s->keep_alive_timeout

-                                       + apr_time_now());

-            }

             break;

         default:

             break;

@@ -1887,6 +1955,7 @@ static void on_stream_state_enter(void *ctx, h2_stream *stream)

         default:

             break;

     }

+    dispatch_event(session, H2_SESSION_EV_STREAM_CHANGE, 0, "stream state change");

 }

 static void on_stream_event(void *ctx, h2_stream *stream, 

@@ -1945,8 +2014,8 @@ static void dispatch_event(h2_session *session, h2_session_event_t ev,

         case H2_SESSION_EV_NO_IO:

             h2_session_ev_no_io(session, arg, msg);

             break;

-        case H2_SESSION_EV_DATA_READ:

-            h2_session_ev_data_read(session, arg, msg);

+        case H2_SESSION_EV_FRAME_RCVD:

+            h2_session_ev_frame_rcvd(session, arg, msg);

             break;

         case H2_SESSION_EV_NGH2_DONE:

             h2_session_ev_ngh2_done(session, arg, msg);

@@ -1957,6 +2026,9 @@ static void dispatch_event(h2_session *session, h2_session_event_t ev,

         case H2_SESSION_EV_PRE_CLOSE:

             h2_session_ev_pre_close(session, arg, msg);

             break;

+        case H2_SESSION_EV_STREAM_CHANGE:

+            h2_session_ev_stream_change(session, arg, msg);

+            break;

         default:

             ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, session->c,

                           H2_SSSN_MSG(session, "unknown event %d"), ev);

@@ -1990,13 +2062,15 @@ apr_status_t h2_session_process(h2_session *session, int async)

     apr_status_t status = APR_SUCCESS;

     conn_rec *c = session->c;

     int rv, mpm_state, trace = APLOGctrace3(c);

-

+    apr_time_t now;

+    

     if (trace) {

         ap_log_cerror( APLOG_MARK, APLOG_TRACE3, status, c,

                       H2_SSSN_MSG(session, "process start, async=%d"), async);

     }

     while (session->state != H2_SESSION_ST_DONE) {

+        now = apr_time_now();

         session->have_read = session->have_written = 0;

         if (session->local.accepting 

@@ -2034,39 +2108,42 @@ apr_status_t h2_session_process(h2_session *session, int async)

                 break;

             case H2_SESSION_ST_IDLE:

-                /* We trust our connection into the default timeout/keepalive

-                 * handling of the core filters/mpm iff:

-                 * - keep_sync_until is not set

-                 * - we have an async mpm

-                 * - we have no open streams to process

-                 * - we are not sitting on a Upgrade: request

-                 * - we already have seen at least one request

-                 */

-                if (!session->keep_sync_until && async && !session->open_streams

-                    && !session->r && session->remote.emitted_count) {

+                if (session->idle_until && (apr_time_now() + session->idle_delay) > session->idle_until) {

+                    ap_log_cerror( APLOG_MARK, APLOG_TRACE1, status, c,

+                                  H2_SSSN_MSG(session, "idle, timeout reached, closing"));

+                    if (session->idle_delay) {

+                        apr_table_setn(session->c->notes, "short-lingering-close", "1"); 

+                    }

+                    dispatch_event(session, H2_SESSION_EV_CONN_TIMEOUT, 0, "timeout");

+                    goto out;

+                }

+                

+                if (session->idle_delay) {

+                    /* we are less interested in spending time on this connection */

+                    ap_log_cerror( APLOG_MARK, APLOG_TRACE2, status, c,

+                                  H2_SSSN_MSG(session, "session is idle (%ld ms), idle wait %ld sec left"), 

+                                  (long)apr_time_as_msec(session->idle_delay),

+                                  (long)apr_time_sec(session->idle_until - now));

+                    apr_sleep(session->idle_delay);

+                    session->idle_delay = 0;

+                }

+

+                h2_conn_io_flush(&session->io);

+                if (async && !session->r && (now > session->idle_sync_until)) {

                     if (trace) {

                         ap_log_cerror(APLOG_MARK, APLOG_TRACE3, status, c,

                                       H2_SSSN_MSG(session, 

                                       "nonblock read, %d streams open"), 

                                       session->open_streams);

                     }

-                    h2_conn_io_flush(&session->io);

                     status = h2_session_read(session, 0);

                     if (status == APR_SUCCESS) {

                         session->have_read = 1;

-                        dispatch_event(session, H2_SESSION_EV_DATA_READ, 0, NULL);

                     }

-                    else if (APR_STATUS_IS_EAGAIN(status) 

-                        || APR_STATUS_IS_TIMEUP(status)) {

-                        if (apr_time_now() > session->idle_until) {

-                            dispatch_event(session, 

-                                           H2_SESSION_EV_CONN_TIMEOUT, 0, NULL);

-                        }

-                        else {

-                            status = APR_EAGAIN;

-                            goto out;

-                        }

+                    else if (APR_STATUS_IS_EAGAIN(status) || APR_STATUS_IS_TIMEUP(status)) {

+                        status = APR_EAGAIN;

+                        goto out;

                     }

                     else {

                         ap_log_cerror(APLOG_MARK, APLOG_DEBUG, status, c,

@@ -2078,7 +2155,6 @@ apr_status_t h2_session_process(h2_session *session, int async)

                 }

                 else {

                     /* make certain, we send everything before we idle */

-                    h2_conn_io_flush(&session->io);

                     if (trace) {

                         ap_log_cerror(APLOG_MARK, APLOG_TRACE3, status, c,

                                       H2_SSSN_MSG(session, 

@@ -2090,7 +2166,6 @@ apr_status_t h2_session_process(h2_session *session, int async)

                      */

                     status = h2_mplx_idle(session->mplx);

                     if (status == APR_EAGAIN) {

-                        dispatch_event(session, H2_SESSION_EV_DATA_READ, 0, NULL);

                         break;

                     }

                     else if (status != APR_SUCCESS) {

@@ -2101,33 +2176,11 @@ apr_status_t h2_session_process(h2_session *session, int async)

                     status = h2_session_read(session, 1);

                     if (status == APR_SUCCESS) {

                         session->have_read = 1;

-                        dispatch_event(session, H2_SESSION_EV_DATA_READ, 0, NULL);

                     }

                     else if (status == APR_EAGAIN) {

                         /* nothing to read */

                     }

                     else if (APR_STATUS_IS_TIMEUP(status)) {

-                        apr_time_t now = apr_time_now();

-                        if (now > session->keep_sync_until) {

-                            /* if we are on an async mpm, now is the time that

-                             * we may dare to pass control to it. */

-                            session->keep_sync_until = 0;

-                        }

-                        if (now > session->idle_until) {

-                            if (trace) {

-                                ap_log_cerror(APLOG_MARK, APLOG_TRACE3, status, c,

-                                              H2_SSSN_MSG(session, 

-                                              "keepalive timeout"));

-                            }

-                            dispatch_event(session, 

-                                           H2_SESSION_EV_CONN_TIMEOUT, 0, "timeout");

-                        }

-                        else if (trace) {                        

-                            ap_log_cerror(APLOG_MARK, APLOG_TRACE3, status, c,

-                                          H2_SSSN_MSG(session, 

-                                          "keepalive, %f sec left"),

-                                          (session->idle_until - now) / 1000000.0f);

-                        }

                         /* continue reading handling */

                     }

                     else if (APR_STATUS_IS_ECONNABORTED(status)

@@ -2145,6 +2198,18 @@ apr_status_t h2_session_process(h2_session *session, int async)

                         dispatch_event(session, H2_SESSION_EV_CONN_ERROR, 0, "error");

                     }

                 }

+                if (nghttp2_session_want_write(session->ngh2)) {

+                    ap_update_child_status(session->c->sbh, SERVER_BUSY_WRITE, NULL);

+                    status = h2_session_send(session);

+                    if (status == APR_SUCCESS) {

+                        status = h2_conn_io_flush(&session->io);

+                    }

+                    if (status != APR_SUCCESS) {

+                        dispatch_event(session, H2_SESSION_EV_CONN_ERROR, 

+                                       H2_ERR_INTERNAL_ERROR, "writing");

+                        break;

+                    }

+                }

                 break;

             case H2_SESSION_ST_BUSY:

@@ -2154,7 +2219,6 @@ apr_status_t h2_session_process(h2_session *session, int async)

                     status = h2_session_read(session, 0);

                     if (status == APR_SUCCESS) {

                         session->have_read = 1;

-                        dispatch_event(session, H2_SESSION_EV_DATA_READ, 0, NULL);

                     }

                     else if (status == APR_EAGAIN) {

                         /* nothing to read */

@@ -2218,7 +2282,7 @@ apr_status_t h2_session_process(h2_session *session, int async)

                                              session->iowait);

                 if (status == APR_SUCCESS) {

                     session->wait_us = 0;

-                    dispatch_event(session, H2_SESSION_EV_DATA_READ, 0, NULL);

+                        dispatch_event(session, H2_SESSION_EV_STREAM_CHANGE, 0, NULL);

                 }

                 else if (APR_STATUS_IS_TIMEUP(status)) {

                     /* go back to checking all inputs again */

diff --git a/modules/http2/h2_session.h b/modules/http2/h2_session.h

index 486938b..452c182 100644

--- a/modules/http2/h2_session.h

+++ b/modules/http2/h2_session.h

@@ -66,10 +66,11 @@ typedef enum {

     H2_SESSION_EV_PROTO_ERROR,      /* protocol error */

     H2_SESSION_EV_CONN_TIMEOUT,     /* connection timeout */

     H2_SESSION_EV_NO_IO,            /* nothing has been read or written */

-    H2_SESSION_EV_DATA_READ,        /* connection data has been read */

+    H2_SESSION_EV_FRAME_RCVD,       /* a frame has been received */

     H2_SESSION_EV_NGH2_DONE,        /* nghttp2 wants neither read nor write anything */

     H2_SESSION_EV_MPM_STOPPING,     /* the process is stopping */

     H2_SESSION_EV_PRE_CLOSE,        /* connection will close after this */

+    H2_SESSION_EV_STREAM_CHANGE,    /* a stream (state/input/output) changed */

 } h2_session_event_t;

 typedef struct h2_session {

@@ -118,8 +119,10 @@ typedef struct h2_session {

     apr_size_t max_stream_mem;      /* max buffer memory for a single stream */

     apr_time_t idle_until;          /* Time we shut down due to sheer boredom */

-    apr_time_t keep_sync_until;     /* Time we sync wait until passing to async mpm */

-    

+    apr_time_t idle_sync_until;     /* Time we sync wait until keepalive handling kicks in */

+    apr_size_t idle_frames;         /* number of rcvd frames that kept session in idle state */

+    apr_interval_time_t idle_delay; /* Time we delay processing rcvd frames in idle state */

+

     apr_bucket_brigade *bbtmp;      /* brigade for keeping temporary data */

     struct apr_thread_cond_t *iowait; /* our cond when trywaiting for data */