Auto merge 5.1-rep-semisync

10 files changed, 519 insertions, 284 deletions

diff --git a/mysql-test/suite/rpl/r/rpl_semi_sync.result b/mysql-test/suite/rpl/r/rpl_semi_sync.result
index d6f2a3aceff..607b77fbd04 100644
--- a/mysql-test/suite/rpl/r/rpl_semi_sync.result
+++ b/mysql-test/suite/rpl/r/rpl_semi_sync.result
@@ -29,13 +29,13 @@ set global rpl_semi_sync_master_enabled = 1;
 show variables like 'rpl_semi_sync_master_enabled';
 Variable_name	Value
 rpl_semi_sync_master_enabled	ON
-[ status of semi-sync on master should be OFF without any semi-sync slaves ]
+[ status of semi-sync on master should be ON even without any semi-sync slaves ]
 show status like 'Rpl_semi_sync_master_clients';
 Variable_name	Value
 Rpl_semi_sync_master_clients	0
 show status like 'Rpl_semi_sync_master_status';
 Variable_name	Value
-Rpl_semi_sync_master_status	OFF
+Rpl_semi_sync_master_status	ON
 show status like 'Rpl_semi_sync_master_yes_tx';
 Variable_name	Value
 Rpl_semi_sync_master_yes_tx	0
@@ -81,7 +81,7 @@ 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
-create table t1(n int) engine = ENGINE_TYPE;
+create table t1(a int) engine = ENGINE_TYPE;
 [ master state after CREATE TABLE statement ]
 show status like 'Rpl_semi_sync_master_status';
 Variable_name	Value
@@ -92,6 +92,9 @@ 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	1
+select CONNECTIONS_NORMAL_SLAVE - CONNECTIONS_NORMAL_SLAVE as 'Should be 0';
+Should be 0
+0
 [ insert records to table ]
 [ master status after inserts ]
 show status like 'Rpl_semi_sync_master_status';
@@ -108,15 +111,19 @@ Rpl_semi_sync_master_yes_tx	301
 show status like 'Rpl_semi_sync_slave_status';
 Variable_name	Value
 Rpl_semi_sync_slave_status	ON
-select count(distinct n) from t1;
-count(distinct n)
+select count(distinct a) from t1;
+count(distinct a)
 300
-select min(n) from t1;
-min(n)
+select min(a) from t1;
+min(a)
 1
-select max(n) from t1;
-max(n)
+select max(a) from t1;
+max(a)
 300
+#
+# Test semi-sync master will switch OFF after one transacton
+# timeout waiting for slave reply.
+#
 include/stop_slave.inc
 [ on master ]
 [ master status should be ON ]
@@ -134,7 +141,16 @@ Variable_name	Value
 Rpl_semi_sync_master_clients	1
 [ semi-sync replication of these transactions will fail ]
 insert into t1 values (500);
-delete from t1 where n < 500;
+[ master status should be OFF ]
+show status like 'Rpl_semi_sync_master_status';
+Variable_name	Value
+Rpl_semi_sync_master_status	OFF
+show status like 'Rpl_semi_sync_master_no_tx';
+Variable_name	Value
+Rpl_semi_sync_master_no_tx	1
+show status like 'Rpl_semi_sync_master_yes_tx';
+Variable_name	Value
+Rpl_semi_sync_master_yes_tx	301
 insert into t1 values (100);
 [ master status should be OFF ]
 show status like 'Rpl_semi_sync_master_status';
@@ -142,10 +158,13 @@ Variable_name	Value
 Rpl_semi_sync_master_status	OFF
 show status like 'Rpl_semi_sync_master_no_tx';
 Variable_name	Value
-Rpl_semi_sync_master_no_tx	3
+Rpl_semi_sync_master_no_tx	302
 show status like 'Rpl_semi_sync_master_yes_tx';
 Variable_name	Value
 Rpl_semi_sync_master_yes_tx	301
+#
+# Test semi-sync status on master will be ON again when slave catches up
+#
 [ on slave ]
 [ slave status should be OFF ]
 show status like 'Rpl_semi_sync_slave_status';
@@ -156,33 +175,53 @@ include/start_slave.inc
 show status like 'Rpl_semi_sync_slave_status';
 Variable_name	Value
 Rpl_semi_sync_slave_status	ON
-select count(distinct n) from t1;
-count(distinct n)
+select count(distinct a) from t1;
+count(distinct a)
 2
-select min(n) from t1;
-min(n)
+select min(a) from t1;
+min(a)
 100
-select max(n) from t1;
-max(n)
+select max(a) from t1;
+max(a)
 500
 [ on master ]
-[ do something to activate semi-sync ]
-drop table t1;
-[ master status should be ON again ]
+[ master status should be ON again after slave catches up ]
 show status like 'Rpl_semi_sync_master_status';
 Variable_name	Value
 Rpl_semi_sync_master_status	ON
 show status like 'Rpl_semi_sync_master_no_tx';
 Variable_name	Value
-Rpl_semi_sync_master_no_tx	3
+Rpl_semi_sync_master_no_tx	302
 show status like 'Rpl_semi_sync_master_yes_tx';
 Variable_name	Value
-Rpl_semi_sync_master_yes_tx	302
+Rpl_semi_sync_master_yes_tx	301
 show status like 'Rpl_semi_sync_master_clients';
 Variable_name	Value
 Rpl_semi_sync_master_clients	1
+#
+# Test disable/enable master semi-sync on the fly.
+#
+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	302
+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
@@ -206,6 +245,9 @@ rpl_semi_sync_master_enabled	ON
 show status like 'Rpl_semi_sync_master_status';
 Variable_name	Value
 Rpl_semi_sync_master_status	ON
+#
+# Test RESET MASTER/SLAVE
+#
 [ on slave ]
 include/start_slave.inc
 [ on master ]
@@ -313,7 +355,7 @@ Variable_name	Value
 Rpl_semi_sync_master_clients	0
 show status like 'Rpl_semi_sync_master_status';
 Variable_name	Value
-Rpl_semi_sync_master_status	OFF
+Rpl_semi_sync_master_status	ON
 set global rpl_semi_sync_master_enabled= 0;
 [ on slave ]
 SHOW VARIABLES LIKE 'rpl_semi_sync_slave_enabled';
@@ -322,17 +364,17 @@ rpl_semi_sync_slave_enabled	ON
 include/start_slave.inc
 [ on master ]
 insert into t1 values (8);
-[ master semi-sync clients should be 0, status should be OFF ]
+[ master semi-sync clients should be 1, status should be OFF ]
 show status like 'Rpl_semi_sync_master_clients';
 Variable_name	Value
-Rpl_semi_sync_master_clients	0
+Rpl_semi_sync_master_clients	1
 show status like 'Rpl_semi_sync_master_status';
 Variable_name	Value
 Rpl_semi_sync_master_status	OFF
 [ on slave ]
 show status like 'Rpl_semi_sync_slave_status';
 Variable_name	Value
-Rpl_semi_sync_slave_status	OFF
+Rpl_semi_sync_slave_status	ON
 include/stop_slave.inc
 [ on master ]
 set sql_log_bin=0;
diff --git a/mysql-test/suite/rpl/t/rpl_semi_sync.test b/mysql-test/suite/rpl/t/rpl_semi_sync.test
index 9798ffdb642..faf961bb580 100644
--- a/mysql-test/suite/rpl/t/rpl_semi_sync.test
+++ b/mysql-test/suite/rpl/t/rpl_semi_sync.test
@@ -11,12 +11,17 @@ let $engine_type= InnoDB;
 disable_query_log;
 connection master;
 call mtr.add_suppression("Timeout waiting for reply of binlog");
+call mtr.add_suppression("Read semi-sync reply");
 connection slave;
-call mtr.add_suppression("Master server does not support");
-# These will be removed after fix bug#45852
-call mtr.add_suppression("Set 'rpl_semi_sync_master_reply_log_file_pos' on master failed");
-call mtr.add_suppression("Slave I/O: Fatal error: Failed to run 'after_queue_event' hook, Error_code: 1593");
+call mtr.add_suppression("Master server does not support semi-sync");
+call mtr.add_suppression("Semi-sync slave .* reply");
 enable_query_log;
+connection master;
+
+# After fix of BUG#45848, semi-sync slave should not create any extra
+# connections on master, save the count of connections before start
+# semi-sync slave for comparison below.
+let $_connections_normal_slave= query_get_value(SHOW STATUS LIKE 'Threads_connected', Value, 1);
 
 --echo #
 --echo # Uninstall semi-sync plugins on master and slave
@@ -69,7 +74,7 @@ echo [ enable semi-sync on master ];
 set global rpl_semi_sync_master_enabled = 1;
 show variables like 'rpl_semi_sync_master_enabled';
 
-echo [ status of semi-sync on master should be OFF without any semi-sync slaves ];
+echo [ status of semi-sync on master should be ON even without any semi-sync slaves ];
 show status like 'Rpl_semi_sync_master_clients';
 show status like 'Rpl_semi_sync_master_status';
 show status like 'Rpl_semi_sync_master_yes_tx';
@@ -150,13 +155,20 @@ show status like 'Rpl_semi_sync_master_no_tx';
 show status like 'Rpl_semi_sync_master_yes_tx';
 
 replace_result $engine_type ENGINE_TYPE;
-eval create table t1(n int) engine = $engine_type;
+eval create table t1(a int) engine = $engine_type;
 
 echo [ master state after CREATE TABLE statement ];
 show status like 'Rpl_semi_sync_master_status';
 show status like 'Rpl_semi_sync_master_no_tx';
 show status like 'Rpl_semi_sync_master_yes_tx';
 
+# After fix of BUG#45848, semi-sync slave should not create any extra
+# connections on master.
+let $_connections_semisync_slave= query_get_value(SHOW STATUS LIKE 'Threads_connected', Value, 1);
+replace_result $_connections_semisync_slave CONNECTIONS_SEMISYNC_SLAVE;
+replace_result $_connections_normal_slave CONNECTIONS_NORMAL_SLAVE;
+eval select $_connections_semisync_slave - $_connections_normal_slave as 'Should be 0';
+
 let $i=300;
 echo [ insert records to table ];
 disable_query_log;
@@ -178,10 +190,15 @@ echo [ on slave ];
 echo [ slave status after replicated inserts ];
 show status like 'Rpl_semi_sync_slave_status';
 
-select count(distinct n) from t1;
-select min(n) from t1;
-select max(n) from t1;
+select count(distinct a) from t1;
+select min(a) from t1;
+select max(a) from t1;
 
+--echo #
+--echo # Test semi-sync master will switch OFF after one transacton
+--echo # timeout waiting for slave reply.
+--echo #
+connection slave;
 source include/stop_slave.inc;
 
 connection master;
@@ -197,8 +214,11 @@ show status like 'Rpl_semi_sync_master_clients';
 
 echo [ semi-sync replication of these transactions will fail ];
 insert into t1 values (500);
-delete from t1 where n < 500;
-insert into t1 values (100);
+
+# Wait for the semi-sync replication of this transaction to timeout
+let $status_var= Rpl_semi_sync_master_status;
+let $status_var_value= OFF;
+source include/wait_for_status_var.inc;
 
 # The second semi-sync check should be off because one transaction
 # times out during waiting.
@@ -207,6 +227,28 @@ show status like 'Rpl_semi_sync_master_status';
 show status like 'Rpl_semi_sync_master_no_tx';
 show status like 'Rpl_semi_sync_master_yes_tx';
 
+# Semi-sync status on master is now OFF, so all these transactions
+# will be replicated asynchronously.
+let $i=300;
+disable_query_log;
+while ($i)
+{
+  eval delete from t1 where a=$i;
+  dec $i;
+}
+enable_query_log;
+
+insert into t1 values (100);
+
+echo [ master status should be OFF ];
+show status like 'Rpl_semi_sync_master_status';
+show status like 'Rpl_semi_sync_master_no_tx';
+show status like 'Rpl_semi_sync_master_yes_tx';
+
+--echo #
+--echo # Test semi-sync status on master will be ON again when slave catches up
+--echo #
+
 # Save the master position for later use.
 save_master_pos;
 
@@ -221,28 +263,44 @@ sync_with_master;
 echo [ slave status should be ON ];
 show status like 'Rpl_semi_sync_slave_status';
 
-select count(distinct n) from t1;
-select min(n) from t1;
-select max(n) from t1;
+select count(distinct a) from t1;
+select min(a) from t1;
+select max(a) from t1;
 
 connection master;
 echo [ on master ];
 
-echo [ do something to activate semi-sync ];
-drop table t1;
-
-# The third semi-sync check should be on again.
-echo [ master status should be ON again ];
+# The master semi-sync status should be on again after slave catches up.
+echo [ master status should be ON again after slave catches up ];
 show status like 'Rpl_semi_sync_master_status';
 show status like 'Rpl_semi_sync_master_no_tx';
 show status like 'Rpl_semi_sync_master_yes_tx';
 show status like 'Rpl_semi_sync_master_clients';
 
+--echo #
+--echo # Test disable/enable master semi-sync on the fly.
+--echo #
+
+drop table t1;
 sync_slave_with_master;
 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 ];
 
@@ -259,6 +317,10 @@ set global rpl_semi_sync_master_enabled=1;
 show variables like 'rpl_semi_sync_master_enabled';
 show status like 'Rpl_semi_sync_master_status';
 
+--echo #
+--echo # Test RESET MASTER/SLAVE
+--echo #
+
 connection slave;
 echo [ on slave ];
 
@@ -435,7 +497,10 @@ source include/start_slave.inc;
 connection master;
 echo [ on master ];
 insert into t1 values (8);
-echo [ master semi-sync clients should be 0, status should be OFF ];
+let $status_var= Rpl_semi_sync_master_clients;
+let $status_var_value= 1;
+source include/wait_for_status_var.inc;
+echo [ master semi-sync clients should be 1, status should be OFF ];
 show status like 'Rpl_semi_sync_master_clients';
 show status like 'Rpl_semi_sync_master_status';
 sync_slave_with_master;
@@ -512,6 +577,8 @@ source include/start_slave.inc;
 
 connection master;
 drop table t1;
+sync_slave_with_master;
+
+connection master;
 drop user rpl@127.0.0.1;
 flush privileges;
-sync_slave_with_master;
diff --git a/plugin/semisync/Makefile.am b/plugin/semisync/Makefile.am
index dd9a630670c..dfe539b8386 100644
--- a/plugin/semisync/Makefile.am
+++ b/plugin/semisync/Makefile.am
@@ -18,6 +18,7 @@
 pkgplugindir =		$(pkglibdir)/plugin
 INCLUDES =              -I$(top_srcdir)/include \
 			-I$(top_srcdir)/sql \
+			-I$(top_srcdir)/regex \
 			-I$(srcdir)
 
 noinst_HEADERS = semisync.h semisync_master.h semisync_slave.h
diff --git a/plugin/semisync/semisync.h b/plugin/semisync/semisync.h
index c9d35a093f6..ced25c40534 100644
--- a/plugin/semisync/semisync.h
+++ b/plugin/semisync/semisync.h
@@ -18,25 +18,9 @@
 #ifndef SEMISYNC_H
 #define SEMISYNC_H
 
-#include <stdint.h>
-#include <string.h>
-#include <assert.h>
-#include <sys/time.h>
-#include <time.h>
-#include <stdio.h>
-#include <pthread.h>
-#include <mysql.h>
-
-typedef uint32_t uint32;
-typedef unsigned long long my_off_t;
-#define FN_REFLEN	512	/* Max length of full path-name */
-void sql_print_error(const char *format, ...);
-void sql_print_warning(const char *format, ...);
-void sql_print_information(const char *format, ...);
-extern unsigned long max_connections;
-
 #define MYSQL_SERVER
 #define HAVE_REPLICATION
+#include <mysql_priv.h>
 #include <my_global.h>
 #include <my_pthread.h>
 #include <mysql/plugin.h>
@@ -92,4 +76,16 @@ public:
   static const unsigned char kPacketFlagSync;
 };
 
+/* The layout of a semisync slave reply packet:
+   1 byte for the magic num
+   8 bytes for the binlog positon
+   n bytes for the binlog filename, terminated with a '\0'
+*/
+#define REPLY_MAGIC_NUM_LEN 1
+#define REPLY_BINLOG_POS_LEN 8
+#define REPLY_BINLOG_NAME_LEN (FN_REFLEN + 1)
+#define REPLY_MAGIC_NUM_OFFSET 0
+#define REPLY_BINLOG_POS_OFFSET (REPLY_MAGIC_NUM_OFFSET + REPLY_MAGIC_NUM_LEN)
+#define REPLY_BINLOG_NAME_OFFSET (REPLY_BINLOG_POS_OFFSET + REPLY_BINLOG_POS_LEN)
+
 #endif /* SEMISYNC_H */
diff --git a/plugin/semisync/semisync_master.cc b/plugin/semisync/semisync_master.cc
index 3641b658268..1a7106621a4 100644
--- a/plugin/semisync/semisync_master.cc
+++ b/plugin/semisync/semisync_master.cc
@@ -30,16 +30,17 @@ 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;
+char rpl_semi_sync_master_wait_no_slave = 1;
 
 
 static int getWaitTime(const struct timeval& start_tv);
@@ -379,16 +380,6 @@ 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_, "");
@@ -535,6 +526,14 @@ void ReplSemiSyncMaster::remove_slave()
 {
   lock();
   rpl_semi_sync_master_clients--;
+
+  /* If user has chosen not to wait if no semi-sync slave available
+     and the last semi-sync slave exits, turn off semi-sync on master
+     immediately.
+   */
+  if (!rpl_semi_sync_master_wait_no_slave &&
+      rpl_semi_sync_master_clients == 0)
+    switch_off();
   unlock();
 }
 
@@ -546,19 +545,6 @@ bool ReplSemiSyncMaster::is_semi_sync_slave()
   return val;
 }
 
-int ReplSemiSyncMaster::reportReplyBinlog(const char *log_file_pos)
-{
-  char log_name[FN_REFLEN];
-  char *endptr;
-  my_off_t log_pos= strtoull(log_file_pos, &endptr, 10);
-  if (!log_pos || !endptr || *endptr != ':' )
-    return 1;
-  endptr++;                                     // skip the ':' seperator
-  strncpy(log_name, endptr, FN_REFLEN);
-  uint32 server_id= 0;
-  return reportReplyBinlog(server_id, log_name, log_pos);
-}
-
 int ReplSemiSyncMaster::reportReplyBinlog(uint32 server_id,
 					  const char *log_file_name,
 					  my_off_t log_file_pos)
@@ -624,7 +610,7 @@ 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.
@@ -679,7 +665,7 @@ int ReplSemiSyncMaster::commitTrx(const char* trx_wait_binlog_name,
                             "Waiting for semi-sync ACK from slave");
 
     /* This is the real check inside the mutex. */
-    if (!getMasterEnabled() || !is_on() || !rpl_semi_sync_master_clients)
+    if (!getMasterEnabled() || !is_on())
       goto l_end;
 
     if (trace_level_ & kTraceDetail)
@@ -691,17 +677,20 @@ int ReplSemiSyncMaster::commitTrx(const char* trx_wait_binlog_name,
 
     while (is_on())
     {
-      int cmp = ActiveTranx::compare(reply_file_name_, reply_file_pos_,
-                                     trx_wait_binlog_name, trx_wait_binlog_pos);
-      if (cmp >= 0)
+      if (reply_file_name_inited_)
       {
-        /* We have already sent the relevant binlog to the slave: no need to
-         * wait here.
-         */
-        if (trace_level_ & kTraceDetail)
-          sql_print_information("%s: Binlog reply is ahead (%s, %lu),",
-                                kWho, reply_file_name_, (unsigned long)reply_file_pos_);
-        break;
+        int cmp = ActiveTranx::compare(reply_file_name_, reply_file_pos_,
+                                       trx_wait_binlog_name, trx_wait_binlog_pos);
+        if (cmp >= 0)
+        {
+          /* We have already sent the relevant binlog to the slave: no need to
+           * wait here.
+           */
+          if (trace_level_ & kTraceDetail)
+            sql_print_information("%s: Binlog reply is ahead (%s, %lu),",
+                                  kWho, reply_file_name_, (unsigned long)reply_file_pos_);
+          break;
+        }
       }
 
       /* Let us update the info about the minimum binlog position of waiting
@@ -709,15 +698,15 @@ int ReplSemiSyncMaster::commitTrx(const char* trx_wait_binlog_name,
        */
       if (wait_file_name_inited_)
       {
-        cmp = ActiveTranx::compare(trx_wait_binlog_name, trx_wait_binlog_pos,
-                                   wait_file_name_, wait_file_pos_);
+        int cmp = ActiveTranx::compare(trx_wait_binlog_name, trx_wait_binlog_pos,
+                                       wait_file_name_, wait_file_pos_);
         if (cmp <= 0)
 	{
           /* This thd has a lower position, let's update the minimum info. */
           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_);
@@ -762,7 +751,7 @@ 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)",
@@ -770,7 +759,7 @@ 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)
 	{
@@ -779,7 +768,7 @@ 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();
@@ -798,12 +787,12 @@ 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;
           }
         }
       }
@@ -816,7 +805,7 @@ 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();
@@ -824,11 +813,18 @@ int ReplSemiSyncMaster::commitTrx(const char* trx_wait_binlog_name,
     }
 
   l_end:
+    /*
+      At this point, the binlog file and position of this transaction
+      must have been removed from ActiveTranx.
+    */
+    assert(!active_tranxs_->is_tranx_end_pos(trx_wait_binlog_name,
+                                             trx_wait_binlog_pos));
+    
     /* Update the status counter. */
-    if (is_on() && rpl_semi_sync_master_clients)
-      enabled_transactions_++;
+    if (is_on())
+      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 */
@@ -868,7 +864,7 @@ 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.");
@@ -1045,7 +1041,9 @@ int ReplSemiSyncMaster::updateSyncHeader(unsigned char *packet,
    * reserve the packet header.
    */
   if (sync)
+  {
     (packet)[2] = kPacketFlagSync;
+  }
 
   return function_exit(kWho, 0);
 }
@@ -1089,7 +1087,7 @@ int ReplSemiSyncMaster::writeTranxInBinlog(const char* log_file_name,
     commit_file_name_inited_ = true;
   }
 
-  if (is_on() && rpl_semi_sync_master_clients)
+  if (is_on())
   {
     assert(active_tranxs_ != NULL);
     if(active_tranxs_->insert_tranx_node(log_file_name, log_file_pos))
@@ -1098,8 +1096,8 @@ int ReplSemiSyncMaster::writeTranxInBinlog(const char* log_file_name,
         if insert tranx_node failed, print a warning message
         and turn off semi-sync
       */
-      sql_print_warning("Semi-sync failed to insert tranx_node for binlog file: %s, position: %ul",
-                        log_file_name, log_file_pos);
+      sql_print_warning("Semi-sync failed to insert tranx_node for binlog file: %s, position: %lu",
+                        log_file_name, (ulong)log_file_pos);
       switch_off();
     }
   }
@@ -1110,6 +1108,113 @@ int ReplSemiSyncMaster::writeTranxInBinlog(const char* log_file_name,
   return function_exit(kWho, result);
 }
 
+int ReplSemiSyncMaster::readSlaveReply(NET *net, uint32 server_id,
+                                       const char *event_buf)
+{
+  const char *kWho = "ReplSemiSyncMaster::readSlaveReply";
+  const unsigned char *packet;
+  char     log_file_name[FN_REFLEN];
+  my_off_t log_file_pos;
+  ulong    packet_len;
+  int      result = -1;
+
+  struct timeval start_tv;
+  int   start_time_err= 0;
+  ulong trc_level = trace_level_;
+
+  function_enter(kWho);
+
+  assert((unsigned char)event_buf[1] == kPacketMagicNum);
+  if ((unsigned char)event_buf[2] != kPacketFlagSync)
+  {
+    /* current event does not require reply */
+    result = 0;
+    goto l_end;
+  }
+
+  if (trc_level & kTraceNetWait)
+    start_time_err = gettimeofday(&start_tv, 0);
+
+  /* We flush to make sure that the current event is sent to the network,
+   * instead of being buffered in the TCP/IP stack.
+   */
+  if (net_flush(net))
+  {
+    sql_print_error("Semi-sync master failed on net_flush() "
+                    "before waiting for slave reply");
+    goto l_end;
+  }
+
+  net_clear(net, 0);
+  if (trc_level & kTraceDetail)
+    sql_print_information("%s: Wait for replica's reply", kWho);
+
+  /* Wait for the network here.  Though binlog dump thread can indefinitely wait
+   * here, transactions would not wait indefintely.
+   * Transactions wait on binlog replies detected by binlog dump threads.  If
+   * binlog dump threads wait too long, transactions will timeout and continue.
+   */
+  packet_len = my_net_read(net);
+
+  if (trc_level & kTraceNetWait)
+  {
+    if (start_time_err != 0)
+    {
+      sql_print_error("Semi-sync master wait for reply "
+                      "gettimeofday fail to get start time");
+      rpl_semi_sync_master_timefunc_fails++;
+    }
+    else
+    {
+      int wait_time;
+
+      wait_time = getWaitTime(start_tv);
+      if (wait_time < 0)
+      {
+        sql_print_error("Semi-sync master wait for reply "
+                        "gettimeofday fail to get wait time.");
+        rpl_semi_sync_master_timefunc_fails++;
+      }
+      else
+      {
+        rpl_semi_sync_master_net_wait_num++;
+        rpl_semi_sync_master_net_wait_time += wait_time;
+      }
+    }
+  }
+
+  if (packet_len == packet_error || packet_len < REPLY_BINLOG_NAME_OFFSET)
+  {
+    if (packet_len == packet_error)
+      sql_print_error("Read semi-sync reply network error: %s (errno: %d)",
+                      net->last_error, net->last_errno);
+    else
+      sql_print_error("Read semi-sync reply length error: %s (errno: %d)",
+                      net->last_error, net->last_errno);
+    goto l_end;
+  }
+
+  packet = net->read_pos;
+  if (packet[REPLY_MAGIC_NUM_OFFSET] != ReplSemiSyncMaster::kPacketMagicNum)
+  {
+    sql_print_error("Read semi-sync reply magic number error");
+    goto l_end;
+  }
+
+  log_file_pos = uint8korr(packet + REPLY_BINLOG_POS_OFFSET);
+  strcpy(log_file_name, (const char*)packet + REPLY_BINLOG_NAME_OFFSET);
+
+  if (trc_level & kTraceDetail)
+    sql_print_information("%s: Got reply (%s, %lu)",
+                          kWho, log_file_name, (ulong)log_file_pos);
+
+  result = reportReplyBinlog(server_id, log_file_name, log_file_pos);
+
+ l_end:
+  return function_exit(kWho, result);
+}
+
+
 int ReplSemiSyncMaster::resetMaster()
 {
   const char *kWho = "ReplSemiSyncMaster::resetMaster";
@@ -1126,16 +1231,16 @@ 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();
 
@@ -1146,27 +1251,15 @@ 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_status           = state_;
+  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();
 }
diff --git a/plugin/semisync/semisync_master.h b/plugin/semisync/semisync_master.h
index bb63cece18a..d2b87745600 100644
--- a/plugin/semisync/semisync_master.h
+++ b/plugin/semisync/semisync_master.h
@@ -81,7 +81,7 @@ public:
   /* Insert an active transaction node with the specified position.
    *
    * Return:
-   *  0: success;  -1 or otherwise: error
+   *  0: success;  non-zero: error
    */
   int insert_tranx_node(const char *log_file_name, my_off_t log_file_pos);
 
@@ -91,7 +91,7 @@ public:
    * list and the hash table will be reset to empty.
    * 
    * Return:
-   *  0: success;  -1 or otherwise: error
+   *  0: success;  non-zero: error
    */
   int clear_active_tranx_nodes(const char *log_file_name,
 			       my_off_t    log_file_pos);
@@ -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.
@@ -253,8 +241,6 @@ class ReplSemiSyncMaster
   /* Is the slave servered by the thread requested semi-sync */
   bool is_semi_sync_slave();
 
-  int reportReplyBinlog(const char *log_file_pos);
-  
   /* In semi-sync replication, reports up to which binlog position we have
    * received replies from the slave indicating that it already get the events.
    *
@@ -265,7 +251,7 @@ class ReplSemiSyncMaster
    *                        the replies from the slave
    *
    * Return:
-   *  0: success;  -1 or otherwise: error
+   *  0: success;  non-zero: error
    */
   int reportReplyBinlog(uint32 server_id,
                         const char* log_file_name,
@@ -284,7 +270,7 @@ class ReplSemiSyncMaster
    *  trx_wait_binlog_pos  - (IN)  ending position's file offset
    *
    * Return:
-   *  0: success;  -1 or otherwise: error
+   *  0: success;  non-zero: error
    */
   int commitTrx(const char* trx_wait_binlog_name,
                 my_off_t trx_wait_binlog_pos);
@@ -313,7 +299,7 @@ class ReplSemiSyncMaster
    *  server_id     - (IN)  master server id number
    *
    * Return:
-   *  0: success;  -1 or otherwise: error
+   *  0: success;  non-zero: error
    */
   int updateSyncHeader(unsigned char *packet,
                        const char *log_file_name,
@@ -330,10 +316,23 @@ class ReplSemiSyncMaster
    *  log_file_pos  - (IN)  transaction ending position's file offset
    *
    * Return:
-   *  0: success;  -1 or otherwise: error
+   *  0: success;  non-zero: error
    */
   int writeTranxInBinlog(const char* log_file_name, my_off_t log_file_pos);
 
+  /* Read the slave's reply so that we know how much progress the slave makes
+   * on receive replication events.
+   * 
+   * Input:
+   *  net          - (IN)  the connection to master
+   *  server_id    - (IN)  master server id number
+   *  event_buf    - (IN)  pointer to the event packet
+   *
+   * Return:
+   *  0: success;  non-zero: error
+   */
+  int readSlaveReply(NET *net, uint32 server_id, const char *event_buf);
+
   /* Export internal statistics for semi-sync replication. */
   void setExportStats();
 
@@ -345,22 +344,31 @@ 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;
+
+/*
+  This indicates whether we should keep waiting if no semi-sync slave
+  is available.
+     0           : stop waiting if detected no avaialable semi-sync slave.
+     1 (default) : keep waiting until timeout even no available semi-sync slave.
+*/
+extern char rpl_semi_sync_master_wait_no_slave;
 
 #endif /* SEMISYNC_MASTER_H */
diff --git a/plugin/semisync/semisync_master_plugin.cc b/plugin/semisync/semisync_master_plugin.cc
index dc19d09e622..d2ef500d932 100644
--- a/plugin/semisync/semisync_master_plugin.cc
+++ b/plugin/semisync/semisync_master_plugin.cc
@@ -69,8 +69,16 @@ int repl_semi_binlog_dump_start(Binlog_transmit_param *param,
   bool semi_sync_slave= repl_semisync.is_semi_sync_slave();
   
   if (semi_sync_slave)
+  {
     /* One more semi-sync slave */
     repl_semisync.add_slave();
+    
+    /*
+      Let's assume this semi-sync slave has already received all
+      binlog events before the filename and position it requests.
+    */
+    repl_semisync.reportReplyBinlog(param->server_id, log_file, log_pos);
+  }
   sql_print_information("Start %s binlog_dump to slave (server_id: %d), pos(%s, %lu)",
 			semi_sync_slave ? "semi-sync" : "asynchronous",
 			param->server_id, log_file, (unsigned long)log_pos);
@@ -114,6 +122,18 @@ int repl_semi_before_send_event(Binlog_transmit_param *param,
 int repl_semi_after_send_event(Binlog_transmit_param *param,
                                const char *event_buf, unsigned long len)
 {
+  if (repl_semisync.is_semi_sync_slave())
+  {
+    THD *thd= current_thd;
+    /*
+      Possible errors in reading slave reply are ignored deliberately
+      because we do not want dump thread to quit on this. Error
+      messages are already reported.
+    */
+    (void) repl_semisync.readSlaveReply(&thd->net,
+                                        param->server_id, event_buf);
+    thd->clear_error();
+  }
   return 0;
 }
 
@@ -142,11 +162,6 @@ static void fix_rpl_semi_sync_master_enabled(MYSQL_THD thd,
 				      void *ptr,
 				      const void *val);
 
-static void fix_rpl_semi_sync_master_reply_log_file_pos(MYSQL_THD thd,
-                                                 SYS_VAR *var,
-                                                 void *ptr,
-                                                 const void *val);
-
 static MYSQL_SYSVAR_BOOL(enabled, rpl_semi_sync_master_enabled,
   PLUGIN_VAR_OPCMDARG,
  "Enable semi-synchronous replication master (disabled by default). ",
@@ -161,6 +176,13 @@ static MYSQL_SYSVAR_ULONG(timeout, rpl_semi_sync_master_timeout,
   fix_rpl_semi_sync_master_timeout,	// update
   10000, 0, ~0L, 1);
 
+static MYSQL_SYSVAR_BOOL(wait_no_slave, rpl_semi_sync_master_wait_no_slave,
+  PLUGIN_VAR_OPCMDARG,
+ "Wait until timeout when no semi-synchronous replication slave available (enabled by default). ",
+  NULL, 			// check
+  NULL,                         // update
+  1);
+
 static MYSQL_SYSVAR_ULONG(trace_level, rpl_semi_sync_master_trace_level,
   PLUGIN_VAR_OPCMDARG,
  "The tracing level for semi-sync replication.",
@@ -168,22 +190,11 @@ static MYSQL_SYSVAR_ULONG(trace_level, rpl_semi_sync_master_trace_level,
   &fix_rpl_semi_sync_master_trace_level, // update
   32, 0, ~0L, 1);
 
-/*
-  Use a SESSION instead of GLOBAL variable for slave to send reply to
-  avoid requiring SUPER privilege.
-*/
-static MYSQL_THDVAR_STR(reply_log_file_pos,
-  PLUGIN_VAR_NOCMDOPT,
-  "The log filename and position slave has queued to relay log.",
-  NULL,             // check
-  &fix_rpl_semi_sync_master_reply_log_file_pos,
-  "");
-
 static SYS_VAR* semi_sync_master_system_vars[]= {
   MYSQL_SYSVAR(enabled),
   MYSQL_SYSVAR(timeout),
+  MYSQL_SYSVAR(wait_no_slave),
   MYSQL_SYSVAR(trace_level),
-  MYSQL_SYSVAR(reply_log_file_pos),
   NULL,
 };
 
@@ -228,19 +239,6 @@ static void fix_rpl_semi_sync_master_enabled(MYSQL_THD thd,
   return;
 }
 
-static void fix_rpl_semi_sync_master_reply_log_file_pos(MYSQL_THD thd,
-                                                 SYS_VAR *var,
-                                                 void *ptr,
-                                                 const void *val)
-{
-  const char *log_file_pos= *(char **)val;
-  
-  if (repl_semisync.reportReplyBinlog(log_file_pos))
-    sql_print_error("report slave binlog reply failed.");
-
-  return;
-}
-
 Trans_observer trans_observer = {
   sizeof(Trans_observer),		// len
 
@@ -278,45 +276,60 @@ 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},
 };
 
diff --git a/plugin/semisync/semisync_slave.cc b/plugin/semisync/semisync_slave.cc
index 3298ce316a8..109577fb688 100644
--- a/plugin/semisync/semisync_slave.cc
+++ b/plugin/semisync/semisync_slave.cc
@@ -39,16 +39,6 @@ int ReplSemiSyncSlave::initObject()
   return result;
 }
 
-int ReplSemiSyncSlave::slaveReplyConnect()
-{
-  if (!mysql_reply && !(mysql_reply= rpl_connect_master(NULL)))
-  {
-    sql_print_error("Semisync slave connect to master for reply failed");
-    return 1;
-  }
-  return 0;
-}
-
 int ReplSemiSyncSlave::slaveReadSyncHeader(const char *header,
                                       unsigned long total_len,
                                       bool  *need_reply,
@@ -104,19 +94,45 @@ int ReplSemiSyncSlave::slaveStop(Binlog_relay_IO_param *param)
   return 0;
 }
 
-int ReplSemiSyncSlave::slaveReply(const char *log_name, my_off_t log_pos)
+int ReplSemiSyncSlave::slaveReply(MYSQL *mysql,
+                                 const char *binlog_filename,
+                                 my_off_t binlog_filepos)
 {
-  char query[FN_REFLEN + 100];
-  sprintf(query, "SET SESSION rpl_semi_sync_master_reply_log_file_pos='%llu:%s'",
-          (unsigned long long)log_pos, log_name);
-  if (mysql_real_query(mysql_reply, query, strlen(query)))
+  const char *kWho = "ReplSemiSyncSlave::slaveReply";
+  NET *net= &mysql->net;
+  uchar reply_buffer[REPLY_MAGIC_NUM_LEN
+                     + REPLY_BINLOG_POS_LEN
+                     + REPLY_BINLOG_NAME_LEN];
+  int  reply_res, name_len = strlen(binlog_filename);
+
+  function_enter(kWho);
+
+  /* Prepare the buffer of the reply. */
+  reply_buffer[REPLY_MAGIC_NUM_OFFSET] = kPacketMagicNum;
+  int8store(reply_buffer + REPLY_BINLOG_POS_OFFSET, binlog_filepos);
+  memcpy(reply_buffer + REPLY_BINLOG_NAME_OFFSET,
+         binlog_filename,
+         name_len + 1 /* including trailing '\0' */);
+
+  if (trace_level_ & kTraceDetail)
+    sql_print_information("%s: reply (%s, %lu)", kWho,
+                          binlog_filename, (ulong)binlog_filepos);
+
+  net_clear(net, 0);
+  /* Send the reply. */
+  reply_res = my_net_write(net, reply_buffer,
+                           name_len + REPLY_BINLOG_NAME_OFFSET);
+  if (!reply_res)
   {
-    sql_print_error("Set 'rpl_semi_sync_master_reply_log_file_pos' on master failed");
-    mysql_free_result(mysql_store_result(mysql_reply));
-    mysql_close(mysql_reply);
-    mysql_reply= 0;
-    return 1;
+    reply_res = net_flush(net);
+    if (reply_res)
+      sql_print_error("Semi-sync slave net_flush() reply failed");
   }
-  mysql_free_result(mysql_store_result(mysql_reply));
-  return 0;
+  else
+  {
+    sql_print_error("Semi-sync slave send reply failed: %s (%d)",
+                    net->last_error, net->last_errno);
+  }
+
+  return function_exit(kWho, reply_res);
 }
diff --git a/plugin/semisync/semisync_slave.h b/plugin/semisync/semisync_slave.h
index 16fa31c69eb..19ea43e2653 100644
--- a/plugin/semisync/semisync_slave.h
+++ b/plugin/semisync/semisync_slave.h
@@ -57,7 +57,7 @@ public:
    *  payload_len - (IN)  payload length
    *
    * Return:
-   *  0: success;  -1 or otherwise: error
+   *  0: success;  non-zero: error
    */
   int slaveReadSyncHeader(const char *header, unsigned long total_len, bool *need_reply,
                           const char **payload, unsigned long *payload_len);
@@ -67,19 +67,16 @@ public:
    * binlog position.
    * 
    * Input:
-   *  log_name         - (IN)  the reply point's binlog file name
-   *  log_pos   - (IN)  the reply point's binlog file offset
+   *  mysql            - (IN)  the mysql network connection
+   *  binlog_filename  - (IN)  the reply point's binlog file name
+   *  binlog_filepos   - (IN)  the reply point's binlog file offset
    *
    * Return:
-   *  0: success;  -1 or otherwise: error
+   *  0: success;  non-zero: error
    */
-  int slaveReply(const char *log_name, my_off_t log_pos);
+  int slaveReply(MYSQL *mysql, const char *binlog_filename,
+                 my_off_t binlog_filepos);
 
-  /*
-    Connect to master for sending reply
-   */
-  int slaveReplyConnect();
-  
   int slaveStart(Binlog_relay_IO_param *param);
   int slaveStop(Binlog_relay_IO_param *param);
 
diff --git a/plugin/semisync/semisync_slave_plugin.cc b/plugin/semisync/semisync_slave_plugin.cc
index ffc663c9bdb..0bd9e1b8b21 100644
--- a/plugin/semisync/semisync_slave_plugin.cc
+++ b/plugin/semisync/semisync_slave_plugin.cc
@@ -45,13 +45,6 @@ int repl_semi_slave_request_dump(Binlog_relay_IO_param *param,
   if (!repl_semisync.getSlaveEnabled())
     return 0;
 
-  /*
-    Create the connection that is used to send slave ACK replies to
-    master
-  */
-  if (repl_semisync.slaveReplyConnect())
-    return 1;
-
   /* Check if master server has semi-sync plugin installed */
   query= "SHOW VARIABLES LIKE 'rpl_semi_sync_master_enabled'";
   if (mysql_real_query(mysql, query, strlen(query)) ||
@@ -63,10 +56,11 @@ int repl_semi_slave_request_dump(Binlog_relay_IO_param *param,
   }
 
   row= mysql_fetch_row(res);
-  if (!row || strcmp(row[1], "ON"))
+  if (!row)
   {
-    /* Master does not support or not configured semi-sync */
-    sql_print_warning("Master server does not support or not configured semi-sync replication, fallback to asynchronous");
+    /* Master does not support semi-sync */
+    sql_print_warning("Master server does not support semi-sync, "
+                      "fallback to asynchronous replication");
     rpl_semi_sync_slave_status= 0;
     return 0;
   }
@@ -106,8 +100,16 @@ int repl_semi_slave_queue_event(Binlog_relay_IO_param *param,
 				uint32 flags)
 {
   if (rpl_semi_sync_slave_status && semi_sync_need_reply)
-    return repl_semisync.slaveReply(param->master_log_name,
+  {
+    /*
+      We deliberately ignore the error in slaveReply, such error
+      should not cause the slave IO thread to stop, and the error
+      messages are already reported.
+    */
+    (void) repl_semisync.slaveReply(param->mysql,
+                                    param->master_log_name,
                                     param->master_log_pos);
+  }
   return 0;
 }