MDEV-7802 Add status binlog_group_commit_reason_*

The following global status variables where added:
* binlog_group_commit_reason_count
* binlog_group_commit_reason_usec
* binlog_group_commit_reason_transaction
* binlog_group_commit_reason_immediate

binlog_group_commit_reason_count corresponds to group commits made by
virtue of the binlog_commit_wait_count variable.

binlog_group_commit_reason_usec corresponds to the binlog_commit_wait_usec
variable.

binlog_group_commit_reason_transaction is a result of ordered
transaction that need to occur in the same order on the slave and can't
be parallelised.

binlog_group_commit_reason_immediate is caused to prevent stalls with
row locks as described in log.cc:binlog_report_wait_for. This immediate
count is also counted a second time in binlog_group_commit_reason_transaction.

Overall binlog_group_commits = binlog_group_commit_reason_count +
binlog_group_commit_reason_usec + binlog_group_commit_reason_transaction

This work was funded thanks to Open Source Developers Club Australia.

mysql-test/suite/binlog/r/binlog_commit_wait.result

@@ -4,6 +4,14 @@ SET @old_count= @@GLOBAL.binlog_commit_wait_count;
 SET GLOBAL binlog_commit_wait_count= 3;
 SET @old_usec= @@GLOBAL.binlog_commit_wait_usec;
 SET GLOBAL binlog_commit_wait_usec= 20000000;
+SELECT variable_value INTO @group_commits FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commits';
+SELECT variable_value INTO @group_commit_reason_count FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_count';
+SELECT variable_value INTO @group_commit_reason_usec FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_usec';
+SELECT variable_value INTO @group_commit_reason_transaction FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_transaction';
 SET @a= current_timestamp();
 BEGIN;
 INSERT INTO t1 VALUES (1,0);
@@ -13,6 +21,22 @@ SET @b= unix_timestamp(current_timestamp()) - unix_timestamp(@a);
 SELECT IF(@b < 20, "Ok", CONCAT("Error: too much time elapsed: ", @b, " seconds >= 20"));
 IF(@b < 20, "Ok", CONCAT("Error: too much time elapsed: ", @b, " seconds >= 20"))
 Ok
+SELECT variable_value - @group_commits FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commits';
+variable_value - @group_commits
+1
+SELECT variable_value - @group_commit_reason_count FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_count';
+variable_value - @group_commit_reason_count
+0
+SELECT variable_value - @group_commit_reason_usec FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_usec';
+variable_value - @group_commit_reason_usec
+0
+SELECT variable_value - @group_commit_reason_transaction FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_transaction';
+variable_value - @group_commit_reason_transaction
+1
 ERROR 23000: Duplicate entry '1' for key 'PRIMARY'
 SET @a= current_timestamp();
 INSERT INTO t1 VALUES (2,0);
@@ -22,6 +46,22 @@ SET @b= unix_timestamp(current_timestamp()) - unix_timestamp(@a);
 SELECT IF(@b < 20, "Ok", CONCAT("Error: too much time elapsed: ", @b, " seconds >= 20"));
 IF(@b < 20, "Ok", CONCAT("Error: too much time elapsed: ", @b, " seconds >= 20"))
 Ok
+SELECT variable_value - @group_commits FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commits';
+variable_value - @group_commits
+2
+SELECT variable_value - @group_commit_reason_count FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_count';
+variable_value - @group_commit_reason_count
+1
+SELECT variable_value - @group_commit_reason_usec FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_usec';
+variable_value - @group_commit_reason_usec
+0
+SELECT variable_value - @group_commit_reason_transaction FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_transaction';
+variable_value - @group_commit_reason_transaction
+1
 SET @a= current_timestamp();
 INSERT INTO t1 VALUES (6,0);
 BEGIN;
@@ -36,6 +76,22 @@ SET @b= unix_timestamp(current_timestamp()) - unix_timestamp(@a);
 SELECT IF(@b < 20, "Ok", CONCAT("Error: too much time elapsed: ", @b, " seconds >= 20"));
 IF(@b < 20, "Ok", CONCAT("Error: too much time elapsed: ", @b, " seconds >= 20"))
 Ok
+SELECT variable_value - @group_commits FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commits';
+variable_value - @group_commits
+3
+SELECT variable_value - @group_commit_reason_count FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_count';
+variable_value - @group_commit_reason_count
+1
+SELECT variable_value - @group_commit_reason_usec FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_usec';
+variable_value - @group_commit_reason_usec
+0
+SELECT variable_value - @group_commit_reason_transaction FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_transaction';
+variable_value - @group_commit_reason_transaction
+2
 SET @a= current_timestamp();
 INSERT INTO t1 VALUES (7,0);
 INSERT INTO t1 VALUES (8,0);
@@ -43,6 +99,47 @@ SET @b= unix_timestamp(current_timestamp()) - unix_timestamp(@a);
 SELECT IF(@b < 20, "Ok", CONCAT("Error: too much time elapsed: ", @b, " seconds >= 20"));
 IF(@b < 20, "Ok", CONCAT("Error: too much time elapsed: ", @b, " seconds >= 20"))
 Ok
+SELECT variable_value - @group_commits FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commits';
+variable_value - @group_commits
+4
+SELECT variable_value - @group_commit_reason_count FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_count';
+variable_value - @group_commit_reason_count
+2
+SELECT variable_value - @group_commit_reason_usec FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_usec';
+variable_value - @group_commit_reason_usec
+0
+SELECT variable_value - @group_commit_reason_transaction FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_transaction';
+variable_value - @group_commit_reason_transaction
+2
+SET @a= current_timestamp();
+SET GLOBAL binlog_commit_wait_usec= 5*1000*1000;
+INSERT INTO t1 VALUES (9,0);
+SET @b= unix_timestamp(current_timestamp()) - unix_timestamp(@a);
+SELECT IF(@b < 4, CONCAT("Error: too little time elapsed: ", @b, " seconds < 4"),
+IF(@b < 20, "Ok", CONCAT("Error: too much time elapsed: ", @b, " seconds >= 20")));
+IF(@b < 4, CONCAT("Error: too little time elapsed: ", @b, " seconds < 4"),
+IF(@b < 20, "Ok", CONCAT("Error: too much time elapsed: ", @b, " seconds >= 20")))
+Ok
+SELECT variable_value - @group_commits FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commits';
+variable_value - @group_commits
+5
+SELECT variable_value - @group_commit_reason_count FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_count';
+variable_value - @group_commit_reason_count
+2
+SELECT variable_value - @group_commit_reason_usec FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_usec';
+variable_value - @group_commit_reason_usec
+1
+SELECT variable_value - @group_commit_reason_transaction FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_transaction';
+variable_value - @group_commit_reason_transaction
+2
 SELECT * FROM t1 ORDER BY a;
 a	b
 1	11
@@ -52,6 +149,7 @@ a	b
 6	0
 7	0
 8	0
+9	0
 DROP TABLE t1;
 SET GLOBAL binlog_commit_wait_count= @old_count;
 SET GLOBAL binlog_commit_wait_usec= @old_usec;

mysql-test/suite/binlog/t/binlog_commit_wait.test

@@ -13,6 +13,20 @@ connect(con1,localhost,root,,test);
 connect(con2,localhost,root,,test);
 connect(con3,localhost,root,,test);
 
+# Get Initial status measurements
+--connection default
+SELECT variable_value INTO @group_commits FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commits';
+SELECT variable_value INTO @group_commit_reason_count FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_count';
+SELECT variable_value INTO @group_commit_reason_usec FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_usec';
+SELECT variable_value INTO @group_commit_reason_transaction FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_transaction';
+
+# Note: binlog_group_commits is counted at the start of the group and group_commit_reason_* is
+# counted near when the groups its finalised.
+
 # Check that if T2 goes to wait for a row lock of T1 while T1 is waiting for
 # more transactions to arrive for group commit, the commit of T1 will complete
 # immediately.
@@ -37,6 +51,18 @@ reap;
 SET @b= unix_timestamp(current_timestamp()) - unix_timestamp(@a);
 SELECT IF(@b < 20, "Ok", CONCAT("Error: too much time elapsed: ", @b, " seconds >= 20"));
 
+# before: binlog_group_commit=0, binlog_group_commit_reason_count=0
+# before: binlog_group_commit_reason_usec=0, binlog_group_commit_reason_transaction=0
+# after:  binlog_group_commit+1 by reason of binlog_group_commit_reason_transaction+1
+SELECT variable_value - @group_commits FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commits';
+SELECT variable_value - @group_commit_reason_count FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_count';
+SELECT variable_value - @group_commit_reason_usec FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_usec';
+SELECT variable_value - @group_commit_reason_transaction FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_transaction';
+
 --connection con2
 --error ER_DUP_ENTRY
 reap;
@@ -64,6 +90,17 @@ reap;
 SET @b= unix_timestamp(current_timestamp()) - unix_timestamp(@a);
 SELECT IF(@b < 20, "Ok", CONCAT("Error: too much time elapsed: ", @b, " seconds >= 20"));
 
+# before: binlog_group_commit=1, binlog_group_commit_reason_count=0
+# before: binlog_group_commit_reason_usec=0, binlog_group_commit_reason_transaction=1
+# after:  binlog_group_commit+1 by reason of binlog_group_commit_reason_count+1
+SELECT variable_value - @group_commits FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commits';
+SELECT variable_value - @group_commit_reason_count FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_count';
+SELECT variable_value - @group_commit_reason_usec FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_usec';
+SELECT variable_value - @group_commit_reason_transaction FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_transaction';
 
 # Test that commit triggers immediately if there is already a transaction
 # waiting on another transaction that reaches its commit.
@@ -99,6 +136,18 @@ reap;
 SET @b= unix_timestamp(current_timestamp()) - unix_timestamp(@a);
 SELECT IF(@b < 20, "Ok", CONCAT("Error: too much time elapsed: ", @b, " seconds >= 20"));
 
+# before: binlog_group_commit=2, binlog_group_commit_reason_count=1
+# before: binlog_group_commit_reason_usec=0, binlog_group_commit_reason_transaction=1
+# after:  binlog_group_commit+1 by reason of binlog_group_commit_reason_transaction+1
+SELECT variable_value - @group_commits FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commits';
+SELECT variable_value - @group_commit_reason_count FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_count';
+SELECT variable_value - @group_commit_reason_usec FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_usec';
+SELECT variable_value - @group_commit_reason_transaction FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_transaction';
+
 --connection default
 SET @a= current_timestamp();
 
@@ -114,6 +163,45 @@ reap;
 SET @b= unix_timestamp(current_timestamp()) - unix_timestamp(@a);
 SELECT IF(@b < 20, "Ok", CONCAT("Error: too much time elapsed: ", @b, " seconds >= 20"));
 
+# before: binlog_group_commit=3, binlog_group_commit_reason_count=1
+# before: binlog_group_commit_reason_usec=0, binlog_group_commit_reason_transaction=2
+# after:  binlog_group_commit+1 by reason of binlog_group_commit_reason_count+1
+SELECT variable_value - @group_commits FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commits';
+SELECT variable_value - @group_commit_reason_count FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_count';
+SELECT variable_value - @group_commit_reason_usec FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_usec';
+SELECT variable_value - @group_commit_reason_transaction FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_transaction';
+
+# Test that when the binlog_commit_wait_usec is reached the tranction gets a group commit
+
+--connection default
+SET @a= current_timestamp();
+SET GLOBAL binlog_commit_wait_usec= 5*1000*1000;
+
+--connection con1
+reap;
+INSERT INTO t1 VALUES (9,0);
+
+--connection default
+SET @b= unix_timestamp(current_timestamp()) - unix_timestamp(@a);
+SELECT IF(@b < 4, CONCAT("Error: too little time elapsed: ", @b, " seconds < 4"),
+          IF(@b < 20, "Ok", CONCAT("Error: too much time elapsed: ", @b, " seconds >= 20")));
+
+# before: binlog_group_commit=4, binlog_group_commit_reason_count=2
+# before: binlog_group_commit_reason_usec=0, binlog_group_commit_reason_transaction=2
+# after:  binlog_group_commit+1 by reason of binlog_group_commit_reason_usec+1
+SELECT variable_value - @group_commits FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commits';
+SELECT variable_value - @group_commit_reason_count FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_count';
+SELECT variable_value - @group_commit_reason_usec FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_usec';
+SELECT variable_value - @group_commit_reason_transaction FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_transaction';
+
 --connection default
 SELECT * FROM t1 ORDER BY a;
 

mysql-test/suite/rpl/r/rpl_parallel_multilevel2.result

@@ -16,6 +16,16 @@ SET @old_updates= @@GLOBAL.binlog_direct_non_transactional_updates;
 SET GLOBAL binlog_direct_non_transactional_updates=OFF;
 SET SESSION binlog_direct_non_transactional_updates=OFF;
 CHANGE MASTER TO master_use_gtid=current_pos;
+SELECT variable_value INTO @group_commits FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commits';
+SELECT variable_value INTO @group_commit_reason_count FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_count';
+SELECT variable_value INTO @group_commit_reason_usec FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_usec';
+SELECT variable_value INTO @group_commit_reason_transaction FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_transaction';
+SELECT variable_value INTO @group_commit_reason_immediate FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_immediate';
 SET @old_parallel_threads=@@GLOBAL.slave_parallel_threads;
 include/stop_slave.inc
 SET GLOBAL slave_parallel_threads=10;
@@ -37,6 +47,26 @@ include/sync_with_master_gtid.inc
 SELECT * FROM t1 ORDER BY a;
 a	b
 1	10
+SELECT variable_value - @group_commits FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commits';
+variable_value - @group_commits
+3
+SELECT variable_value - @group_commit_reason_count FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_count';
+variable_value - @group_commit_reason_count
+0
+SELECT variable_value - @group_commit_reason_usec FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_usec';
+variable_value - @group_commit_reason_usec
+3
+SELECT variable_value - @group_commit_reason_transaction FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_transaction';
+variable_value - @group_commit_reason_transaction
+0
+SELECT variable_value - @group_commit_reason_immediate FROM information_schema.global_status
+WHERE variable_name = 'binlog_group_commit_reason_immediate';
+variable_value - @group_commit_reason_immediate
+0
 include/stop_slave.inc
 SET GLOBAL slave_parallel_threads=@old_parallel_threads;
 SET GLOBAL binlog_commit_wait_count=@old_commit_count;

mysql-test/suite/rpl/t/rpl_parallel_multilevel2.test

@@ -27,6 +27,24 @@ SET GLOBAL binlog_direct_non_transactional_updates=OFF;
 SET SESSION binlog_direct_non_transactional_updates=OFF;
 CHANGE MASTER TO master_use_gtid=current_pos;
 
+# Get Initial status measurements
+# we take out measurements from server_2 as that's where
+# the its critical that 3 separate binlog_group_commits occur
+SELECT variable_value INTO @group_commits FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commits';
+SELECT variable_value INTO @group_commit_reason_count FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_count';
+SELECT variable_value INTO @group_commit_reason_usec FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_usec';
+SELECT variable_value INTO @group_commit_reason_transaction FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_transaction';
+SELECT variable_value INTO @group_commit_reason_immediate FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_immediate';
+
+# Note: binlog_group_commits is counted at the start of the group and group_commit_reason_* is
+# counted near when the groups its finalised.
+
+
 --connection server_3
 --sync_with_master
 --save_master_pos
@@ -56,6 +74,18 @@ SELECT * FROM t1 ORDER BY a;
 --source include/sync_with_master_gtid.inc
 SELECT * FROM t1 ORDER BY a;
 
+# Measure status(es)
+--connection server_2
+SELECT variable_value - @group_commits FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commits';
+SELECT variable_value - @group_commit_reason_count FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_count';
+SELECT variable_value - @group_commit_reason_usec FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_usec';
+SELECT variable_value - @group_commit_reason_transaction FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_transaction';
+SELECT variable_value - @group_commit_reason_immediate FROM information_schema.global_status
+ WHERE variable_name = 'binlog_group_commit_reason_immediate';
 
 # Clean up
 

sql/log.cc

@@ -95,6 +95,10 @@ mysql_mutex_t LOCK_commit_ordered;
 
 static ulonglong binlog_status_var_num_commits;
 static ulonglong binlog_status_var_num_group_commits;
+static ulonglong binlog_status_group_commit_reason_count;
+static ulonglong binlog_status_group_commit_reason_immediate;
+static ulonglong binlog_status_group_commit_reason_transaction;
+static ulonglong binlog_status_group_commit_reason_usec;
 static char binlog_snapshot_file[FN_REFLEN];
 static ulonglong binlog_snapshot_position;
 
@@ -104,6 +108,14 @@ static SHOW_VAR binlog_status_vars_detail[]=
     (char *)&binlog_status_var_num_commits, SHOW_LONGLONG},
   {"group_commits",
     (char *)&binlog_status_var_num_group_commits, SHOW_LONGLONG},
+  {"group_commit_reason_count",
+    (char *)&binlog_status_group_commit_reason_count, SHOW_LONGLONG},
+  {"group_commit_reason_immediate",
+    (char *)&binlog_status_group_commit_reason_immediate, SHOW_LONGLONG},
+  {"group_commit_reason_transaction",
+    (char *)&binlog_status_group_commit_reason_transaction, SHOW_LONGLONG},
+  {"group_commit_reason_usec",
+    (char *)&binlog_status_group_commit_reason_usec, SHOW_LONGLONG},
   {"snapshot_file",
     (char *)&binlog_snapshot_file, SHOW_CHAR},
   {"snapshot_position",
@@ -3035,6 +3047,8 @@ MYSQL_BIN_LOG::MYSQL_BIN_LOG(uint *sync_period)
    bytes_written(0), file_id(1), open_count(1),
    group_commit_queue(0), group_commit_queue_busy(FALSE),
    num_commits(0), num_group_commits(0),
+   group_commit_reason_count(0), group_commit_reason_usec(0),
+   group_commit_reason_transaction(0), group_commit_reason_immediate(0),
    sync_period_ptr(sync_period), sync_counter(0),
    state_file_deleted(false), binlog_state_recover_done(false),
    is_relay_log(0), signal_cnt(0),
@@ -7543,8 +7557,18 @@ MYSQL_BIN_LOG::wait_for_sufficient_commits()
   mysql_mutex_assert_owner(&LOCK_prepare_ordered);
 
   for (e= last_head= group_commit_queue, count= 0; e; e= e->next)
-    if (++count >= opt_binlog_commit_wait_count || unlikely(e->thd->has_waiter))
+  {
+    if (++count >= opt_binlog_commit_wait_count)
+    {
+      group_commit_reason_count++;
+      return;
+    }
+    if (unlikely(e->thd->has_waiter))
+    {
+      group_commit_reason_transaction++;
       return;
+    }
+  }
 
   mysql_mutex_unlock(&LOCK_log);
   set_timespec_nsec(wait_until, (ulonglong)1000*opt_binlog_commit_wait_usec);
@@ -7557,18 +7581,30 @@ MYSQL_BIN_LOG::wait_for_sufficient_commits()
     err= mysql_cond_timedwait(&COND_prepare_ordered, &LOCK_prepare_ordered,
                               &wait_until);
     if (err == ETIMEDOUT)
+    {
+      group_commit_reason_usec++;
       break;
+    }
     if (unlikely(last_head->thd->has_waiter))
+    {
+      group_commit_reason_transaction++;
       break;
+    }
     head= group_commit_queue;
     for (e= head; e && e != last_head; e= e->next)
     {
       ++count;
       if (unlikely(e->thd->has_waiter))
+      {
+        group_commit_reason_transaction++;
         goto after_loop;
+      }
     }
     if (count >= opt_binlog_commit_wait_count)
+    {
+      group_commit_reason_count++;
       break;
+    }
     last_head= head;
   }
 after_loop:
@@ -7603,6 +7639,7 @@ MYSQL_BIN_LOG::binlog_trigger_immediate_group_commit()
   head= group_commit_queue;
   if (head)
   {
+    group_commit_reason_immediate++;
     head->thd->has_waiter= true;
     mysql_cond_signal(&COND_prepare_ordered);
   }
@@ -9746,6 +9783,10 @@ TC_LOG_BINLOG::set_status_variables(THD *thd)
   mysql_mutex_lock(&LOCK_commit_ordered);
   binlog_status_var_num_commits= this->num_commits;
   binlog_status_var_num_group_commits= this->num_group_commits;
+  binlog_status_group_commit_reason_count= this->group_commit_reason_count;
+  binlog_status_group_commit_reason_usec= this->group_commit_reason_usec;
+  binlog_status_group_commit_reason_transaction= this->group_commit_reason_transaction;
+  binlog_status_group_commit_reason_immediate= this->group_commit_reason_immediate;
   if (!have_snapshot)
   {
     set_binlog_snapshot_file(last_commit_pos_file);

sql/log.h

@@ -515,6 +515,9 @@ class MYSQL_BIN_LOG: public TC_LOG, private MYSQL_LOG
   ulonglong num_commits;
   /* Number of group commits done. */
   ulonglong num_group_commits;
+  /* The reason why the group commit was grouped */
+  ulonglong group_commit_reason_count, group_commit_reason_usec;
+  ulonglong group_commit_reason_transaction, group_commit_reason_immediate;
 
   /* pointer to the sync period variable, for binlog this will be
      sync_binlog_period, for relay log this will be