Stream: upstream response time variables.

The $upstream_connect_time, $upstream_first_byte_time and
$upstream_session_time variables keep corresponding times.

src/stream/ngx_stream_proxy_module.c

@@ -684,6 +684,10 @@ ngx_stream_proxy_connect(ngx_stream_session_t *s)
 
     u = s->upstream;
 
+    if (u->state) {
+        u->state->response_time = ngx_current_msec - u->state->response_time;
+    }
+
     u->state = ngx_array_push(s->upstream_states);
     if (u->state == NULL) {
         ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
@@ -692,6 +696,10 @@ ngx_stream_proxy_connect(ngx_stream_session_t *s)
 
     ngx_memzero(u->state, sizeof(ngx_stream_upstream_state_t));
 
+    u->state->connect_time = (ngx_msec_t) -1;
+    u->state->first_byte_time = (ngx_msec_t) -1;
+    u->state->response_time = ngx_current_msec;
+
     rc = ngx_event_connect_peer(&u->peer);
 
     ngx_log_debug1(NGX_LOG_DEBUG_STREAM, c->log, 0, "proxy connect: %i", rc);
@@ -813,6 +821,8 @@ ngx_stream_proxy_init_upstream(ngx_stream_session_t *s)
         }
     }
 
+    u->state->connect_time = ngx_current_msec - u->state->response_time;
+
     c->log->action = "proxying connection";
 
     if (u->upstream_buf.start == NULL) {
@@ -1518,6 +1528,13 @@ ngx_stream_proxy_process(ngx_stream_session_t *s, ngx_uint_t from_upstream,
                     }
                 }
 
+                if (from_upstream) {
+                    if (u->state->first_byte_time == (ngx_msec_t) -1) {
+                        u->state->first_byte_time = ngx_current_msec
+                                                    - u->state->response_time;
+                    }
+                }
+
                 if (c->type == SOCK_DGRAM && ++u->responses == pscf->responses)
                 {
                     src->read->ready = 0;
@@ -1664,6 +1681,8 @@ ngx_stream_proxy_finalize(ngx_stream_session_t *s, ngx_uint_t rc)
     pc = u->peer.connection;
 
     if (u->state) {
+        u->state->response_time = ngx_current_msec - u->state->response_time;
+
         if (pc) {
             u->state->bytes_received = u->received;
             u->state->bytes_sent = pc->sent;

src/stream/ngx_stream_upstream.c

@@ -13,6 +13,8 @@
 static ngx_int_t ngx_stream_upstream_add_variables(ngx_conf_t *cf);
 static ngx_int_t ngx_stream_upstream_addr_variable(ngx_stream_session_t *s,
     ngx_stream_variable_value_t *v, uintptr_t data);
+static ngx_int_t ngx_stream_upstream_response_time_variable(
+    ngx_stream_session_t *s, ngx_stream_variable_value_t *v, uintptr_t data);
 static ngx_int_t ngx_stream_upstream_bytes_variable(ngx_stream_session_t *s,
     ngx_stream_variable_value_t *v, uintptr_t data);
 
@@ -82,6 +84,18 @@ static ngx_stream_variable_t  ngx_stream_upstream_vars[] = {
       ngx_stream_upstream_bytes_variable, 0,
       NGX_STREAM_VAR_NOCACHEABLE, 0 },
 
+    { ngx_string("upstream_connect_time"), NULL,
+      ngx_stream_upstream_response_time_variable, 2,
+      NGX_STREAM_VAR_NOCACHEABLE, 0 },
+
+    { ngx_string("upstream_first_byte_time"), NULL,
+      ngx_stream_upstream_response_time_variable, 1,
+      NGX_STREAM_VAR_NOCACHEABLE, 0 },
+
+    { ngx_string("upstream_session_time"), NULL,
+      ngx_stream_upstream_response_time_variable, 0,
+      NGX_STREAM_VAR_NOCACHEABLE, 0 },
+
     { ngx_string("upstream_bytes_received"), NULL,
       ngx_stream_upstream_bytes_variable, 1,
       NGX_STREAM_VAR_NOCACHEABLE, 0 },
@@ -219,6 +233,73 @@ ngx_stream_upstream_bytes_variable(ngx_stream_session_t *s,
 }
 
 
+static ngx_int_t
+ngx_stream_upstream_response_time_variable(ngx_stream_session_t *s,
+    ngx_stream_variable_value_t *v, uintptr_t data)
+{
+    u_char                       *p;
+    size_t                        len;
+    ngx_uint_t                    i;
+    ngx_msec_int_t                ms;
+    ngx_stream_upstream_state_t  *state;
+
+    v->valid = 1;
+    v->no_cacheable = 0;
+    v->not_found = 0;
+
+    if (s->upstream_states == NULL || s->upstream_states->nelts == 0) {
+        v->not_found = 1;
+        return NGX_OK;
+    }
+
+    len = s->upstream_states->nelts * (NGX_TIME_T_LEN + 4 + 2);
+
+    p = ngx_pnalloc(s->connection->pool, len);
+    if (p == NULL) {
+        return NGX_ERROR;
+    }
+
+    v->data = p;
+
+    i = 0;
+    state = s->upstream_states->elts;
+
+    for ( ;; ) {
+
+        if (data == 1) {
+            if (state[i].first_byte_time == (ngx_msec_t) -1) {
+                *p++ = '-';
+                goto next;
+            }
+
+            ms = state[i].first_byte_time;
+
+        } else if (data == 2 && state[i].connect_time != (ngx_msec_t) -1) {
+            ms = state[i].connect_time;
+
+        } else {
+            ms = state[i].response_time;
+        }
+
+        ms = ngx_max(ms, 0);
+        p = ngx_sprintf(p, "%T.%03M", (time_t) ms / 1000, ms % 1000);
+
+    next:
+
+        if (++i == s->upstream_states->nelts) {
+            break;
+        }
+
+        *p++ = ',';
+        *p++ = ' ';
+    }
+
+    v->len = p - v->data;
+
+    return NGX_OK;
+}
+
+
 static char *
 ngx_stream_upstream(ngx_conf_t *cf, ngx_command_t *cmd, void *dummy)
 {

src/stream/ngx_stream_upstream.h

@@ -79,6 +79,9 @@ struct ngx_stream_upstream_srv_conf_s {
 
 
 typedef struct {
+    ngx_msec_t                         response_time;
+    ngx_msec_t                         connect_time;
+    ngx_msec_t                         first_byte_time;
     off_t                              bytes_sent;
     off_t                              bytes_received;