BUG#45674 FLUSH STATUS does not reset semisynchronous counters

Semi-sync status were not reset by FLUSH STATUS, this was because
all semi-sync status variables are defined as SHOW_FUNC and FLUSH
STATUS could only reset SHOW_LONG type variables.

This problem is fixed by change all status variables that should
be reset by FLUSH STATUS from SHOW_FUNC to SHOW_LONG.

After the fix, the following status variables will be reset by
FLUSH STATUS:
  Rpl_semi_sync_master_yes_tx
  Rpl_semi_sync_master_no_tx

Note: normally, FLUSH STATUS itself will be written into binlog
and be replicated, so after FLUSH STATS, one of
  Rpl_semi_sync_master_yes_tx
  Rpl_semi_sync_master_no_tx
can be 1 dependent on the semi-sync status. So it's recommended
to use FLUSH NO_WRITE_TO_BINLOG STATUS to avoid this.

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

@@ -204,6 +204,24 @@ Rpl_semi_sync_master_clients	1
 drop table t1;
 [ on slave ]
 include/stop_slave.inc
+#
+# Flush status
+#
+[ Semi-sync master status variables before FLUSH STATUS ]
+SHOW STATUS LIKE 'Rpl_semi_sync_master_no_tx';
+Variable_name	Value
+Rpl_semi_sync_master_no_tx	3
+SHOW STATUS LIKE 'Rpl_semi_sync_master_yes_tx';
+Variable_name	Value
+Rpl_semi_sync_master_yes_tx	302
+FLUSH NO_WRITE_TO_BINLOG STATUS;
+[ Semi-sync master status variables after FLUSH STATUS ]
+SHOW STATUS LIKE 'Rpl_semi_sync_master_no_tx';
+Variable_name	Value
+Rpl_semi_sync_master_no_tx	0
+SHOW STATUS LIKE 'Rpl_semi_sync_master_yes_tx';
+Variable_name	Value
+Rpl_semi_sync_master_yes_tx	0
 [ on master ]
 show master logs;
 Log_name	master-bin.000001

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

@@ -287,6 +287,20 @@ echo [ on slave ];
 
 source include/stop_slave.inc;
 
+--echo #
+--echo # Flush status
+--echo #
+connection master;
+echo [ Semi-sync master status variables before FLUSH STATUS ];
+SHOW STATUS LIKE 'Rpl_semi_sync_master_no_tx';
+SHOW STATUS LIKE 'Rpl_semi_sync_master_yes_tx';
+# Do not write the FLUSH STATUS to binlog, to make sure we'll get a
+# clean status after this.
+FLUSH NO_WRITE_TO_BINLOG STATUS;
+echo [ Semi-sync master status variables after FLUSH STATUS ];
+SHOW STATUS LIKE 'Rpl_semi_sync_master_no_tx';
+SHOW STATUS LIKE 'Rpl_semi_sync_master_yes_tx';
+
 connection master;
 echo [ on master ];
 

plugin/semisync/semisync_master.cc

@@ -30,16 +30,16 @@ unsigned long rpl_semi_sync_master_yes_transactions = 0;
 unsigned long rpl_semi_sync_master_no_transactions  = 0;
 unsigned long rpl_semi_sync_master_off_times        = 0;
 unsigned long rpl_semi_sync_master_timefunc_fails   = 0;
-unsigned long rpl_semi_sync_master_num_timeouts     = 0;
+unsigned long rpl_semi_sync_master_wait_timeouts     = 0;
 unsigned long rpl_semi_sync_master_wait_sessions    = 0;
-unsigned long rpl_semi_sync_master_back_wait_pos    = 0;
-unsigned long rpl_semi_sync_master_trx_wait_time    = 0;
+unsigned long rpl_semi_sync_master_wait_pos_backtraverse = 0;
+unsigned long rpl_semi_sync_master_avg_trx_wait_time = 0;
 unsigned long long rpl_semi_sync_master_trx_wait_num = 0;
-unsigned long rpl_semi_sync_master_net_wait_time    = 0;
+unsigned long rpl_semi_sync_master_avg_net_wait_time    = 0;
 unsigned long long rpl_semi_sync_master_net_wait_num = 0;
 unsigned long rpl_semi_sync_master_clients          = 0;
-unsigned long long rpl_semi_sync_master_net_wait_total_time = 0;
-unsigned long long rpl_semi_sync_master_trx_wait_total_time = 0;
+unsigned long long rpl_semi_sync_master_net_wait_time = 0;
+unsigned long long rpl_semi_sync_master_trx_wait_time = 0;
 
 
 static int getWaitTime(const struct timeval& start_tv);
@@ -379,16 +379,6 @@ ReplSemiSyncMaster::ReplSemiSyncMaster()
     master_enabled_(false),
     wait_timeout_(0L),
     state_(0),
-    enabled_transactions_(0),
-    disabled_transactions_(0),
-    switched_off_times_(0),
-    timefunc_fails_(0),
-    wait_sessions_(0),
-    wait_backtraverse_(0),
-    total_trx_wait_num_(0),
-    total_trx_wait_time_(0),
-    total_net_wait_num_(0),
-    total_net_wait_time_(0),
     max_transactions_(0L)
 {
   strcpy(reply_file_name_, "");
@@ -611,7 +601,7 @@ int ReplSemiSyncMaster::reportReplyBinlog(uint32 server_id,
                             log_file_name, (unsigned long)log_file_pos);
   }
 
-  if (wait_sessions_ > 0)
+  if (rpl_semi_sync_master_wait_sessions > 0)
   {
     /* Let us check if some of the waiting threads doing a trx
      * commit can now proceed.
@@ -707,7 +697,7 @@ int ReplSemiSyncMaster::commitTrx(const char* trx_wait_binlog_name,
           strcpy(wait_file_name_, trx_wait_binlog_name);
           wait_file_pos_ = trx_wait_binlog_pos;
 
-          wait_backtraverse_++;
+          rpl_semi_sync_master_wait_pos_backtraverse++;
           if (trace_level_ & kTraceDetail)
             sql_print_information("%s: move back wait position (%s, %lu),",
                                   kWho, wait_file_name_, (unsigned long)wait_file_pos_);
@@ -752,7 +742,7 @@ int ReplSemiSyncMaster::commitTrx(const char* trx_wait_binlog_name,
          * when replication has progressed far enough, we will release
          * these waiting threads.
          */
-        wait_sessions_++;
+        rpl_semi_sync_master_wait_sessions++;
 
         if (trace_level_ & kTraceDetail)
           sql_print_information("%s: wait %lu ms for binlog sent (%s, %lu)",
@@ -760,7 +750,7 @@ int ReplSemiSyncMaster::commitTrx(const char* trx_wait_binlog_name,
                                 wait_file_name_, (unsigned long)wait_file_pos_);
 
         wait_result = cond_timewait(&abstime);
-        wait_sessions_--;
+        rpl_semi_sync_master_wait_sessions--;
 
         if (wait_result != 0)
 	{
@@ -769,7 +759,7 @@ int ReplSemiSyncMaster::commitTrx(const char* trx_wait_binlog_name,
                             "semi-sync up to file %s, position %lu.",
                             trx_wait_binlog_name, (unsigned long)trx_wait_binlog_pos,
                             reply_file_name_, (unsigned long)reply_file_pos_);
-          total_wait_timeouts_++;
+          rpl_semi_sync_master_wait_timeouts++;
 
           /* switch semi-sync off */
           switch_off();
@@ -788,12 +778,12 @@ int ReplSemiSyncMaster::commitTrx(const char* trx_wait_binlog_name,
                               "wait position (%s, %lu)",
                               trx_wait_binlog_name, (unsigned long)trx_wait_binlog_pos);
             }
-            timefunc_fails_++;
+            rpl_semi_sync_master_timefunc_fails++;
           }
 	  else
 	  {
-            total_trx_wait_num_++;
-            total_trx_wait_time_ += wait_time;
+            rpl_semi_sync_master_trx_wait_num++;
+            rpl_semi_sync_master_trx_wait_time += wait_time;
           }
         }
       }
@@ -806,7 +796,7 @@ int ReplSemiSyncMaster::commitTrx(const char* trx_wait_binlog_name,
                           "wait position (%s, %lu)",
                           trx_wait_binlog_name, (unsigned long)trx_wait_binlog_pos);
         }
-        timefunc_fails_++;
+        rpl_semi_sync_master_timefunc_fails++;
 
         /* switch semi-sync off */
         switch_off();
@@ -823,9 +813,9 @@ int ReplSemiSyncMaster::commitTrx(const char* trx_wait_binlog_name,
     
     /* Update the status counter. */
     if (is_on() && rpl_semi_sync_master_clients)
-      enabled_transactions_++;
+      rpl_semi_sync_master_yes_transactions++;
     else
-      disabled_transactions_++;
+      rpl_semi_sync_master_no_transactions++;
 
     /* The lock held will be released by thd_exit_cond, so no need to
        call unlock() here */
@@ -865,7 +855,7 @@ int ReplSemiSyncMaster::switch_off()
   assert(active_tranxs_ != NULL);
   result = active_tranxs_->clear_active_tranx_nodes(NULL, 0);
 
-  switched_off_times_++;
+  rpl_semi_sync_master_off_times++;
   wait_file_name_inited_   = false;
   reply_file_name_inited_  = false;
   sql_print_information("Semi-sync replication switched OFF.");
@@ -1232,16 +1222,16 @@ int ReplSemiSyncMaster::resetMaster()
   reply_file_name_inited_  = false;
   commit_file_name_inited_ = false;
 
-  enabled_transactions_ = 0;
-  disabled_transactions_ = 0;
-  switched_off_times_ = 0;
-  timefunc_fails_ = 0;
-  wait_sessions_ = 0;
-  wait_backtraverse_ = 0;
-  total_trx_wait_num_ = 0;
-  total_trx_wait_time_ = 0;
-  total_net_wait_num_ = 0;
-  total_net_wait_time_ = 0;
+  rpl_semi_sync_master_yes_transactions = 0;
+  rpl_semi_sync_master_no_transactions = 0;
+  rpl_semi_sync_master_off_times = 0;
+  rpl_semi_sync_master_timefunc_fails = 0;
+  rpl_semi_sync_master_wait_sessions = 0;
+  rpl_semi_sync_master_wait_pos_backtraverse = 0;
+  rpl_semi_sync_master_trx_wait_num = 0;
+  rpl_semi_sync_master_trx_wait_time = 0;
+  rpl_semi_sync_master_net_wait_num = 0;
+  rpl_semi_sync_master_net_wait_time = 0;
 
   unlock();
 
@@ -1253,26 +1243,14 @@ void ReplSemiSyncMaster::setExportStats()
   lock();
 
   rpl_semi_sync_master_status           = state_ && rpl_semi_sync_master_clients;
-  rpl_semi_sync_master_yes_transactions = enabled_transactions_;
-  rpl_semi_sync_master_no_transactions  = disabled_transactions_;
-  rpl_semi_sync_master_off_times        = switched_off_times_;
-  rpl_semi_sync_master_timefunc_fails   = timefunc_fails_;
-  rpl_semi_sync_master_num_timeouts     = total_wait_timeouts_;
-  rpl_semi_sync_master_wait_sessions    = wait_sessions_;
-  rpl_semi_sync_master_back_wait_pos    = wait_backtraverse_;
-  rpl_semi_sync_master_trx_wait_num     = total_trx_wait_num_;
-  rpl_semi_sync_master_trx_wait_time    =
-    ((total_trx_wait_num_) ?
-     (unsigned long)((double)total_trx_wait_time_ /
-             ((double)total_trx_wait_num_)) : 0);
-  rpl_semi_sync_master_net_wait_num     = total_net_wait_num_;
-  rpl_semi_sync_master_net_wait_time    =
-    ((total_net_wait_num_) ?
-     (unsigned long)((double)total_net_wait_time_ /
-             ((double)total_net_wait_num_)) : 0);
-
-  rpl_semi_sync_master_net_wait_total_time = total_net_wait_time_;
-  rpl_semi_sync_master_trx_wait_total_time = total_trx_wait_time_;
+  rpl_semi_sync_master_avg_trx_wait_time=
+    ((rpl_semi_sync_master_trx_wait_num) ?
+     (unsigned long)((double)rpl_semi_sync_master_trx_wait_time /
+                     ((double)rpl_semi_sync_master_trx_wait_num)) : 0);
+  rpl_semi_sync_master_avg_net_wait_time=
+    ((rpl_semi_sync_master_net_wait_num) ?
+     (unsigned long)((double)rpl_semi_sync_master_net_wait_time /
+                     ((double)rpl_semi_sync_master_net_wait_num)) : 0);
 
   unlock();
 }

plugin/semisync/semisync_master.h

@@ -175,19 +175,7 @@ class ReplSemiSyncMaster
   volatile bool            master_enabled_;      /* semi-sync is enabled on the master */
   unsigned long           wait_timeout_;      /* timeout period(ms) during tranx wait */
 
-  /* All status variables. */
   bool            state_;                    /* whether semi-sync is switched */
-  unsigned long           enabled_transactions_;          /* semi-sync'ed tansactions */
-  unsigned long           disabled_transactions_;     /* non-semi-sync'ed tansactions */
-  unsigned long           switched_off_times_;    /* how many times are switched off? */
-  unsigned long           timefunc_fails_;           /* how many time function fails? */
-  unsigned long           total_wait_timeouts_;      /* total number of wait timeouts */
-  unsigned long           wait_sessions_;      /* how many sessions wait for replies? */
-  unsigned long           wait_backtraverse_;         /* wait position back traverses */
-  unsigned long long       total_trx_wait_num_;   /* total trx waits: non-timeout ones */
-  unsigned long long       total_trx_wait_time_;         /* total trx wait time: in us */
-  unsigned long long       total_net_wait_num_;                 /* total network waits */
-  unsigned long long       total_net_wait_time_;            /* total network wait time */
 
   /* The number of maximum active transactions.  This should be the same as
    * maximum connections because MySQL does not do connection sharing now.
@@ -356,22 +344,23 @@ class ReplSemiSyncMaster
 
 /* System and status variables for the master component */
 extern char rpl_semi_sync_master_enabled;
+extern char rpl_semi_sync_master_status;
+extern unsigned long rpl_semi_sync_master_clients;
 extern unsigned long rpl_semi_sync_master_timeout;
 extern unsigned long rpl_semi_sync_master_trace_level;
-extern char rpl_semi_sync_master_status;
 extern unsigned long rpl_semi_sync_master_yes_transactions;
 extern unsigned long rpl_semi_sync_master_no_transactions;
 extern unsigned long rpl_semi_sync_master_off_times;
+extern unsigned long rpl_semi_sync_master_wait_timeouts;
 extern unsigned long rpl_semi_sync_master_timefunc_fails;
 extern unsigned long rpl_semi_sync_master_num_timeouts;
 extern unsigned long rpl_semi_sync_master_wait_sessions;
-extern unsigned long rpl_semi_sync_master_back_wait_pos;
-extern unsigned long rpl_semi_sync_master_trx_wait_time;
-extern unsigned long rpl_semi_sync_master_net_wait_time;
+extern unsigned long rpl_semi_sync_master_wait_pos_backtraverse;
+extern unsigned long rpl_semi_sync_master_avg_trx_wait_time;
+extern unsigned long rpl_semi_sync_master_avg_net_wait_time;
 extern unsigned long long rpl_semi_sync_master_net_wait_num;
 extern unsigned long long rpl_semi_sync_master_trx_wait_num;
-extern unsigned long long rpl_semi_sync_master_net_wait_total_time;
-extern unsigned long long rpl_semi_sync_master_trx_wait_total_time;
-extern unsigned long rpl_semi_sync_master_clients;
+extern unsigned long long rpl_semi_sync_master_net_wait_time;
+extern unsigned long long rpl_semi_sync_master_trx_wait_time;
 
 #endif /* SEMISYNC_MASTER_H */

plugin/semisync/semisync_master_plugin.cc

@@ -268,45 +268,60 @@ Binlog_transmit_observer transmit_observer = {
     return 0;								\
   }
 
-DEF_SHOW_FUNC(clients, SHOW_LONG)
-DEF_SHOW_FUNC(net_wait_time, SHOW_LONG)
-DEF_SHOW_FUNC(net_wait_total_time, SHOW_LONGLONG)
-DEF_SHOW_FUNC(net_wait_num, SHOW_LONGLONG)
-DEF_SHOW_FUNC(off_times, SHOW_LONG)
-DEF_SHOW_FUNC(no_transactions, SHOW_LONG)
 DEF_SHOW_FUNC(status, SHOW_BOOL)
-DEF_SHOW_FUNC(timefunc_fails, SHOW_LONG)
-DEF_SHOW_FUNC(trx_wait_time, SHOW_LONG)
-DEF_SHOW_FUNC(trx_wait_total_time, SHOW_LONGLONG)
+DEF_SHOW_FUNC(clients, SHOW_LONG)
+DEF_SHOW_FUNC(trx_wait_time, SHOW_LONGLONG)
 DEF_SHOW_FUNC(trx_wait_num, SHOW_LONGLONG)
-DEF_SHOW_FUNC(back_wait_pos, SHOW_LONG)
-DEF_SHOW_FUNC(wait_sessions, SHOW_LONG)
-DEF_SHOW_FUNC(yes_transactions, SHOW_LONG)
+DEF_SHOW_FUNC(net_wait_time, SHOW_LONGLONG)
+DEF_SHOW_FUNC(net_wait_num, SHOW_LONGLONG)
+DEF_SHOW_FUNC(avg_net_wait_time, SHOW_LONG)
+DEF_SHOW_FUNC(avg_trx_wait_time, SHOW_LONG)
 
 
 /* plugin status variables */
 static SHOW_VAR semi_sync_master_status_vars[]= {
-  {"Rpl_semi_sync_master_clients",    (char*) &SHOW_FNAME(clients),         SHOW_FUNC},
-  {"Rpl_semi_sync_master_net_avg_wait_time",
-                               (char*) &SHOW_FNAME(net_wait_time),   SHOW_FUNC},
-  {"Rpl_semi_sync_master_net_wait_time",
-                               (char*) &SHOW_FNAME(net_wait_total_time),   SHOW_FUNC},
-  {"Rpl_semi_sync_master_net_waits",  (char*) &SHOW_FNAME(net_wait_num),    SHOW_FUNC},
-  {"Rpl_semi_sync_master_no_times",   (char*) &SHOW_FNAME(off_times),       SHOW_FUNC},
-  {"Rpl_semi_sync_master_no_tx",      (char*) &SHOW_FNAME(no_transactions), SHOW_FUNC},
-  {"Rpl_semi_sync_master_status",     (char*) &SHOW_FNAME(status),          SHOW_FUNC},
+  {"Rpl_semi_sync_master_status",
+   (char*) &SHOW_FNAME(status),
+   SHOW_FUNC},
+  {"Rpl_semi_sync_master_clients",
+   (char*) &SHOW_FNAME(clients),
+   SHOW_FUNC},
+  {"Rpl_semi_sync_master_yes_tx",
+   (char*) &rpl_semi_sync_master_yes_transactions,
+   SHOW_LONG},
+  {"Rpl_semi_sync_master_no_tx",
+   (char*) &rpl_semi_sync_master_no_transactions,
+   SHOW_LONG},
+  {"Rpl_semi_sync_master_wait_sessions",
+   (char*) &rpl_semi_sync_master_wait_sessions,
+   SHOW_LONG},
+  {"Rpl_semi_sync_master_no_times",
+   (char*) &rpl_semi_sync_master_off_times,
+   SHOW_LONG},
   {"Rpl_semi_sync_master_timefunc_failures",
-                               (char*) &SHOW_FNAME(timefunc_fails),  SHOW_FUNC},
-  {"Rpl_semi_sync_master_tx_avg_wait_time",
-                               (char*) &SHOW_FNAME(trx_wait_time),   SHOW_FUNC},
-  {"Rpl_semi_sync_master_tx_wait_time",
-                               (char*) &SHOW_FNAME(trx_wait_total_time),   SHOW_FUNC},
-  {"Rpl_semi_sync_master_tx_waits",   (char*) &SHOW_FNAME(trx_wait_num),    SHOW_FUNC},
+   (char*) &rpl_semi_sync_master_timefunc_fails,
+   SHOW_LONG},
   {"Rpl_semi_sync_master_wait_pos_backtraverse",
-                               (char*) &SHOW_FNAME(back_wait_pos),   SHOW_FUNC},
-  {"Rpl_semi_sync_master_wait_sessions",
-                               (char*) &SHOW_FNAME(wait_sessions),   SHOW_FUNC},
-  {"Rpl_semi_sync_master_yes_tx",     (char*) &SHOW_FNAME(yes_transactions), SHOW_FUNC},
+   (char*) &rpl_semi_sync_master_wait_pos_backtraverse,
+   SHOW_LONG},
+  {"Rpl_semi_sync_master_tx_wait_time",
+   (char*) &SHOW_FNAME(trx_wait_time),
+   SHOW_FUNC},
+  {"Rpl_semi_sync_master_tx_waits",
+   (char*) &SHOW_FNAME(trx_wait_num),
+   SHOW_FUNC},
+  {"Rpl_semi_sync_master_tx_avg_wait_time",
+   (char*) &SHOW_FNAME(avg_trx_wait_time),
+   SHOW_FUNC},
+  {"Rpl_semi_sync_master_net_wait_time",
+   (char*) &SHOW_FNAME(net_wait_time),
+   SHOW_FUNC},
+  {"Rpl_semi_sync_master_net_waits",
+   (char*) &SHOW_FNAME(net_wait_num),
+   SHOW_FUNC},
+  {"Rpl_semi_sync_master_net_avg_wait_time",
+   (char*) &SHOW_FNAME(avg_net_wait_time),
+   SHOW_FUNC},
   {NULL, NULL, SHOW_LONG},
 };