mdev-7802-binlog_groupcommit_stats

Update the description of each test case as to why it is
counted in the correct binlog_group_commit_trigger_* variable.

Updated rpl_parallel_multilevel2.test to identify that 3 groups
occur in statement and mixed replication and one group in row based
replication.

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

@@ -51,6 +51,11 @@ reap;
 SET @b= unix_timestamp(current_timestamp()) - unix_timestamp(@a);
 SELECT IF(@b < 20, "Ok", CONCAT("Error: too much time elapsed: ", @b, " seconds >= 20"));
 
+# All connections are to the same server. One transaction occurs on con1. It is
+# commited before con2 is started. con2 transaction violates the unique key contraint. This
+# type of group commit is binlog_group_commit_trigger_lock_wait so that further con2
+# transactions will occur afterwards as they may be as result of the ER_DUP_ENTRY on the 
+# application side.
 # before: binlog_group_commit=0, binlog_group_commit_trigger_count=0
 # before: binlog_group_commit_trigger_timeout=0, binlog_group_commit_trigger_lock_wait=0
 # after:  binlog_group_commit+1 by reason of binlog_group_commit_trigger_lock_wait+1
@@ -90,6 +95,10 @@ reap;
 SET @b= unix_timestamp(current_timestamp()) - unix_timestamp(@a);
 SELECT IF(@b < 20, "Ok", CONCAT("Error: too much time elapsed: ", @b, " seconds >= 20"));
 
+# All connections are to the same server. 3 non-conflicting transaction occur
+# on each connection. The binlog_commit_wait_count=3 at the start therefore 1
+# group is committed by virtue of reaching 3 transactions. Hence
+# binlog_group_commit_trigger_count is incremented.
 # before: binlog_group_commit=1, binlog_group_commit_trigger_count=0
 # before: binlog_group_commit_trigger_timeout=0, binlog_group_commit_trigger_lock_wait=1
 # after:  binlog_group_commit+1 by reason of binlog_group_commit_trigger_count+1
@@ -136,6 +145,9 @@ reap;
 SET @b= unix_timestamp(current_timestamp()) - unix_timestamp(@a);
 SELECT IF(@b < 20, "Ok", CONCAT("Error: too much time elapsed: ", @b, " seconds >= 20"));
 
+# All connections are to the same server. con2 and con3 updates are aquiring
+# the same row lock for a=1. Either con2 or con3 will be in a lock wait
+# thefore the binlog_group_commit_trigger_lock_wait is incremented.
 # before: binlog_group_commit=2, binlog_group_commit_trigger_count=1
 # before: binlog_group_commit_trigger_timeout=0, binlog_group_commit_trigger_lock_wait=1
 # after:  binlog_group_commit+1 by reason of binlog_group_commit_trigger_lock_wait+1
@@ -163,6 +175,8 @@ reap;
 SET @b= unix_timestamp(current_timestamp()) - unix_timestamp(@a);
 SELECT IF(@b < 20, "Ok", CONCAT("Error: too much time elapsed: ", @b, " seconds >= 20"));
 
+# The con1 and con2 transactions above are combined with the 'send UPDATE t1 SET b=b+10 WHERE a=1;'
+# on con3 from the previous block. So we have 3 so this is a count based group.
 # before: binlog_group_commit=3, binlog_group_commit_trigger_count=1
 # before: binlog_group_commit_trigger_timeout=0, binlog_group_commit_trigger_lock_wait=2
 # after:  binlog_group_commit+1 by reason of binlog_group_commit_trigger_count+1
@@ -190,6 +204,10 @@ 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")));
 
+# con1 pushes 1 transaction. The count was for 3 to occur before a group commit.
+# The timeout is 5 seconds but we allow between 4 and 20 because of the fragile nature
+# of time in test. This is a timeout causing the commit so binlog_group_commit_trigger_timeout
+# is incremented.
 # before: binlog_group_commit=4, binlog_group_commit_trigger_count=2
 # before: binlog_group_commit_trigger_timeout=0, binlog_group_commit_trigger_lock_wait=2
 # after:  binlog_group_commit+1 by reason of binlog_group_commit_trigger_timeout+1

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

@@ -45,21 +45,21 @@ include/sync_with_master_gtid.inc
 SELECT * FROM t1 ORDER BY a;
 a	b
 1	10
-SELECT IF((commits.variable_value - @group_commits) IN (1,3), "OK", "Not 1 or 3 groups"),
-((commits.variable_value - @group_commits) - (trigger_timeout.variable_value - @group_commit_trigger_timeout)) as diff
+SELECT IF((commits.variable_value - @group_commits)=IF(@@binlog_format='ROW',1,3), "OK", "Not 1 (row) or 3 (mixed/statement replication) groups"),
+((commits.variable_value - @group_commits) - (trigger_timeout.variable_value - @group_commit_trigger_timeout)) as non_timeout_triggers
 FROM information_schema.global_status commits
 JOIN  information_schema.global_status trigger_timeout
 WHERE commits.variable_name = 'binlog_group_commits'
  AND trigger_timeout.variable_name = 'binlog_group_commit_trigger_timeout';
-IF((commits.variable_value - @group_commits) IN (1,3), "OK", "Not 1 or 3 groups")	diff
+IF((commits.variable_value - @group_commits)=IF(@@binlog_format='ROW',1,3), "OK", "Not 1 (row) or 3 (mixed/statement replication) groups")	non_timeout_triggers
 OK	0
-SELECT variable_value - @group_commit_trigger_count FROM information_schema.global_status
+SELECT variable_value - @group_commit_trigger_count as trigger_count FROM information_schema.global_status
 WHERE variable_name = 'binlog_group_commit_trigger_count';
-variable_value - @group_commit_trigger_count
+trigger_count
 0
-SELECT variable_value - @group_commit_trigger_lock_wait FROM information_schema.global_status
+SELECT variable_value - @group_commit_trigger_lock_wait as trigger_lock_wait FROM information_schema.global_status
 WHERE variable_name = 'binlog_group_commit_trigger_lock_wait';
-variable_value - @group_commit_trigger_lock_wait
+trigger_lock_wait
 0
 include/stop_slave.inc
 SET GLOBAL slave_parallel_threads=@old_parallel_threads;

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

@@ -29,7 +29,7 @@ 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
+# the its critical that 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_trigger_count FROM information_schema.global_status
@@ -74,15 +74,24 @@ SELECT * FROM t1 ORDER BY a;
 
 # Measure status(es)
 --connection server_2
-SELECT IF((commits.variable_value - @group_commits) IN (1,3), "OK", "Not 1 or 3 groups"),
- ((commits.variable_value - @group_commits) - (trigger_timeout.variable_value - @group_commit_trigger_timeout)) as diff
+# A create tempory table being a DDL needs to be its own group for SBR.
+# RBR has table maps which indicate that the temp table needs to be created first.
+# In SBR the first insert from server 1 is begins the second group. The second 
+# insert statement depends on the first it has to be ordered in a third group.
+# 1 group is generated in row based replication as the insert into t1 is values rather than references to t2
+# and the table map indicates that the temp table needs to be created first.
+# 3 groups are generated in mixed/statement based replication
+# All groups result in a binlog_group_commit_trigger_timeout as no other
+# transactions are pushed to server_2 so therefore non_timeout_triggers is 0.
+SELECT IF((commits.variable_value - @group_commits)=IF(@@binlog_format='ROW',1,3), "OK", "Not 1 (row) or 3 (mixed/statement replication) groups"),
+ ((commits.variable_value - @group_commits) - (trigger_timeout.variable_value - @group_commit_trigger_timeout)) as non_timeout_triggers
  FROM information_schema.global_status commits
  JOIN  information_schema.global_status trigger_timeout
  WHERE commits.variable_name = 'binlog_group_commits'
  AND trigger_timeout.variable_name = 'binlog_group_commit_trigger_timeout';
-SELECT variable_value - @group_commit_trigger_count FROM information_schema.global_status
+SELECT variable_value - @group_commit_trigger_count as trigger_count FROM information_schema.global_status
  WHERE variable_name = 'binlog_group_commit_trigger_count';
-SELECT variable_value - @group_commit_trigger_lock_wait FROM information_schema.global_status
+SELECT variable_value - @group_commit_trigger_lock_wait as trigger_lock_wait FROM information_schema.global_status
  WHERE variable_name = 'binlog_group_commit_trigger_lock_wait';
 
 # Clean up