Add Master_gtid_wait_{count,time,timeouts} status

MASTER_GTID_WAIT function needs some status to evaluate its use.

master_gtid_wait_count indicates how many times the function is called.
master_gtid_wait_time indicates how much time in microseconds occurred
waiting (or timing out)
master_gtid_timeouts indicates how many time times this function timed
out rather than all successful gtids events being available.

mysql-test/suite/rpl/r/rpl_gtid_basic.result

@@ -231,6 +231,15 @@ NULL
 SELECT master_gtid_wait('', NULL);
 master_gtid_wait('', NULL)
 0
+SHOW STATUS LIKE 'Master_gtid_wait_count';
+Variable_name	Value
+Master_gtid_wait_count	1
+SHOW STATUS LIKE 'Master_gtid_wait_timeouts';
+Variable_name	Value
+Master_gtid_wait_timeouts	0
+SHOW STATUS LIKE 'Master_gtid_wait_time';
+Variable_name	Value
+Master_gtid_wait_time	0
 SELECT master_gtid_wait(@pos, 0.5);
 master_gtid_wait(@pos, 0.5)
 -1
@@ -271,13 +280,43 @@ SELECT master_gtid_wait('2-1-5');
 SELECT master_gtid_wait('2-1-10');
 SELECT master_gtid_wait('2-1-5,1-1-4,0-1-110');
 SELECT master_gtid_wait('2-1-2');
+SHOW STATUS LIKE 'Master_gtid_wait_timeouts';
+Variable_name	Value
+Master_gtid_wait_timeouts	0
+SHOW STATUS LIKE 'Master_gtid_wait_count';
+Variable_name	Value
+Master_gtid_wait_count	3
 SELECT master_gtid_wait('1-1-1');
 master_gtid_wait('1-1-1')
 0
+SHOW STATUS LIKE 'Master_gtid_wait_timeouts';
+Variable_name	Value
+Master_gtid_wait_timeouts	0
+SHOW STATUS LIKE 'Master_gtid_wait_count';
+Variable_name	Value
+Master_gtid_wait_count	4
+SELECT MASTER_GTID_WAIT_TIME <= 1000000 AS Master_gtid_wait_less_than_second;
+Master_gtid_wait_less_than_second
+1
 SELECT master_gtid_wait('0-1-109');
+SHOW STATUS LIKE 'Master_gtid_wait_timeouts';
+Variable_name	Value
+Master_gtid_wait_timeouts	0
+SHOW STATUS LIKE 'Master_gtid_wait_count';
+Variable_name	Value
+Master_gtid_wait_count	4
 SELECT master_gtid_wait('2-1-2', 0.5);
 master_gtid_wait('2-1-2', 0.5)
 -1
+SHOW STATUS LIKE 'Master_gtid_wait_timeouts';
+Variable_name	Value
+Master_gtid_wait_timeouts	1
+SHOW STATUS LIKE 'Master_gtid_wait_count';
+Variable_name	Value
+Master_gtid_wait_count	5
+SELECT MASTER_GTID_WAIT_TIME BETWEEN 500000 AND 3000000 AS Master_gtid_wait_time_between_half_and_3_seconds;
+Master_gtid_wait_time_between_half_and_3_seconds
+1
 KILL QUERY KILL_ID;
 ERROR 70100: Query execution was interrupted
 SET gtid_domain_id=2;
@@ -433,6 +472,5 @@ a
 31
 32
 33
-34
 DROP TABLE t1;
 include/rpl_end.inc

mysql-test/suite/rpl/t/rpl_gtid_basic.test

@@ -232,6 +232,10 @@ eval SET @pos= '$pos';
 SELECT master_gtid_wait(NULL);
 # Check empty argument returns immediately.
 SELECT master_gtid_wait('', NULL);
+# Check this gets counted
+SHOW STATUS LIKE 'Master_gtid_wait_count';
+SHOW STATUS LIKE 'Master_gtid_wait_timeouts';
+SHOW STATUS LIKE 'Master_gtid_wait_time';
 # Let's check that we get a timeout
 SELECT master_gtid_wait(@pos, 0.5);
 SELECT * FROM t1 ORDER BY a;
@@ -276,7 +280,7 @@ SELECT master_gtid_wait('1-1-1', 0);
 send SELECT master_gtid_wait('2-1-1,1-1-4,0-1-110');
 
 --connect (s2,127.0.0.1,root,,test,$SERVER_MYPORT_2,)
-# This will time out.
+# This will time out. No event 0-1-1000 exists
 send SELECT master_gtid_wait('0-1-1000', 0.5);
 
 --connect (s3,127.0.0.1,root,,test,$SERVER_MYPORT_2,)
@@ -305,15 +309,31 @@ send SELECT master_gtid_wait('2-1-5,1-1-4,0-1-110');
 send SELECT master_gtid_wait('2-1-2');
 
 --connection server_2
-# This one completes immediately.
+# This one completes immediately ( < 1 ms).
+SHOW STATUS LIKE 'Master_gtid_wait_timeouts';
+SHOW STATUS LIKE 'Master_gtid_wait_count';
 SELECT master_gtid_wait('1-1-1');
+SHOW STATUS LIKE 'Master_gtid_wait_timeouts';
+SHOW STATUS LIKE 'Master_gtid_wait_count';
+let $wait_time = query_get_value(SHOW STATUS LIKE 'Master_gtid_wait_time', Value, 1);
+--replace_result $wait_time MASTER_GTID_WAIT_TIME
+eval SELECT $wait_time <= 1000000 AS Master_gtid_wait_less_than_second;
+
 
 --connect (s10,127.0.0.1,root,,test,$SERVER_MYPORT_2,)
 send SELECT master_gtid_wait('0-1-109');
 
 --connection server_2
 # This one should time out.
+SHOW STATUS LIKE 'Master_gtid_wait_timeouts';
+SHOW STATUS LIKE 'Master_gtid_wait_count';
 SELECT master_gtid_wait('2-1-2', 0.5);
+SHOW STATUS LIKE 'Master_gtid_wait_timeouts';
+SHOW STATUS LIKE 'Master_gtid_wait_count';
+# (0.5-3 seconds)
+let $wait_time = query_get_value(SHOW STATUS LIKE 'Master_gtid_wait_time', Value, 1);
+--replace_result $wait_time MASTER_GTID_WAIT_TIME
+eval SELECT $wait_time BETWEEN 500000 AND 3000000 AS Master_gtid_wait_time_between_half_and_3_seconds;
 
 --replace_result $kill1_id KILL_ID
 eval KILL QUERY $kill1_id;

sql/mysqld.cc

@@ -7879,6 +7879,9 @@ SHOW_VAR status_vars[]= {
   {"Handler_write",            (char*) offsetof(STATUS_VAR, ha_write_count), SHOW_LONG_STATUS},
   {"Key",                      (char*) &show_default_keycache, SHOW_FUNC},
   {"Last_query_cost",          (char*) offsetof(STATUS_VAR, last_query_cost), SHOW_DOUBLE_STATUS},
+  {"Master_gtid_wait_count",   (char*) offsetof(STATUS_VAR, master_gtid_wait_count), SHOW_LONGLONG_STATUS},
+  {"Master_gtid_wait_timeouts", (char*) offsetof(STATUS_VAR, master_gtid_wait_timeouts), SHOW_LONGLONG_STATUS},
+  {"Master_gtid_wait_time",    (char*) offsetof(STATUS_VAR, master_gtid_wait_time), SHOW_LONGLONG_STATUS},
   {"Max_used_connections",     (char*) &max_used_connections,  SHOW_LONG},
   {"Memory_used",              (char*) offsetof(STATUS_VAR, memory_used), SHOW_LONGLONG_STATUS},
   {"Not_flushed_delayed_rows", (char*) &delayed_rows_in_use,    SHOW_LONG_NOFLUSH},

sql/rpl_gtid.cc

@@ -1911,10 +1911,14 @@ gtid_waiting::wait_for_pos(THD *thd, String *gtid_str, longlong timeout_us)
   rpl_gtid *wait_pos;
   uint32 count, i;
   struct timespec wait_until, *wait_until_ptr;
+  ulonglong before;
 
   /* Wait for the empty position returns immediately. */
   if (gtid_str->length() == 0)
+  {
+    status_var_increment(thd->status_var.master_gtid_wait_count);
     return 0;
+  }
 
   if (!(wait_pos= gtid_parse_string_to_list(gtid_str->ptr(), gtid_str->length(),
                                             &count)))
@@ -1922,6 +1926,8 @@ gtid_waiting::wait_for_pos(THD *thd, String *gtid_str, longlong timeout_us)
     my_error(ER_INCORRECT_GTID_STATE, MYF(0));
     return 1;
   }
+  status_var_increment(thd->status_var.master_gtid_wait_count);
+  before = microsecond_interval_timer();
 
   if (timeout_us >= 0)
   {
@@ -1936,6 +1942,13 @@ gtid_waiting::wait_for_pos(THD *thd, String *gtid_str, longlong timeout_us)
     if ((err= wait_for_gtid(thd, &wait_pos[i], wait_until_ptr)))
       break;
   }
+  switch (err)
+  {
+    case -1:
+      status_var_increment(thd->status_var.master_gtid_wait_timeouts);
+    case 0: /* deliberate fall through */
+      status_var_add(thd->status_var.master_gtid_wait_time, microsecond_interval_timer() - before);
+  }
   my_free(wait_pos);
   return err;
 }

sql/sql_class.h

@@ -726,6 +726,11 @@ typedef struct system_status_var
   ulong feature_trigger;	    /* +1 opening a table with triggers */
   ulong feature_xml;		    /* +1 when XPATH is used */
 
+  /* From MASTER_GTID_WAIT usage */
+  ulonglong master_gtid_wait_timeouts; /* # of timeouts */
+  ulonglong master_gtid_wait_time; /* Time in microseconds */
+  ulonglong master_gtid_wait_count;
+
   ulong empty_queries;
   ulong access_denied_errors;
   ulong lost_connections;