two new troubleshooting stats

accepting_conns for completeness, and listen_disabled_num to see how many
times you've hit maxconns and disabled incoming connections. probably a good
stat to monitor and flip out on.

memcached.c

@@ -160,7 +160,8 @@ static rel_time_t realtime(const time_t exptime) {
 static void stats_init(void) {
     stats.curr_items = stats.total_items = stats.curr_conns = stats.total_conns = stats.conn_structs = 0;
     stats.get_cmds = stats.set_cmds = stats.get_hits = stats.get_misses = stats.evictions = 0;
-    stats.curr_bytes = 0;
+    stats.curr_bytes = stats.listen_disabled_num = 0;
+    stats.accepting_conns = 1; /* assuming we start in this state. */
 
     /* make the time we started always be 2 seconds before we really
        did, so time(0) - time.started is never zero.  if so, things
@@ -2224,7 +2225,8 @@ static char *server_stats(uint32_t (*add_stats)(char *buf, const char *key,
     APPEND_STAT("bytes_read", "%llu", (unsigned long long)thread_stats.bytes_read);
     APPEND_STAT("bytes_written", "%llu", (unsigned long long)thread_stats.bytes_written);
     APPEND_STAT("limit_maxbytes", "%llu", (unsigned long long)settings.maxbytes);
-    APPEND_STAT("bytes_written", "%llu", (unsigned long long)thread_stats.bytes_written);
+    APPEND_STAT("accepting_conns", "%u", stats.accepting_conns);
+    APPEND_STAT("listen_disabled_num", "%llu", (unsigned long long)stats.listen_disabled_num);
     APPEND_STAT("threads", "%d", settings.num_threads);
 
     if(*buflen > 0 && (buf = malloc(*buflen)) == NULL) {
@@ -3242,7 +3244,18 @@ void accept_new_conns(const bool do_accept) {
                 perror("listen");
             }
         }
-  }
+    }
+
+    if (do_accept) {
+        STATS_LOCK();
+        stats.accepting_conns = 1;
+        STATS_UNLOCK();
+    } else {
+        STATS_LOCK();
+        stats.accepting_conns = 0;
+        stats.listen_disabled_num++;
+        STATS_UNLOCK();
+    }
 }
 
 /*

memcached.h

@@ -108,6 +108,9 @@ struct stats {
     uint64_t      get_hits;
     uint64_t      get_misses;
     uint64_t      evictions;
+    time_t        started;          /* when the process was started */
+    unsigned int  accepting_conns;  /* whether we are currently accepting */
+    uint64_t      listen_disabled_num;
 };
 
 #define MAX_VERBOSITY_LEVEL 2

t/stats.t

@@ -1,7 +1,7 @@
 #!/usr/bin/perl
 
 use strict;
-use Test::More tests => 91;
+use Test::More tests => 93;
 use FindBin qw($Bin);
 use lib "$Bin/lib";
 use MemcachedTest;
@@ -47,14 +47,15 @@ my $sock = $server->sock;
 my $stats = mem_stats($sock);
 
 # Test number of keys
-is(scalar(keys(%$stats)), 32, "32 stats values");
+is(scalar(keys(%$stats)), 34, "34 stats values");
 
 # Test initial state
 foreach my $key (qw(curr_items total_items bytes cmd_get cmd_set get_hits evictions get_misses
                  bytes_written delete_hits delete_misses incr_hits incr_misses decr_hits
-                 decr_misses)) {
+                 decr_misses listen_disabled_num)) {
     is($stats->{$key}, 0, "initial $key is zero");
 }
+is($stats->{accepting_conns}, 1, "initial accepting_conns is one");
 
 # Do some operations