rpl_semi_sync_master_trace_level and rpl_semi_sync_slave_trace_level have no effect (dead system variables)

#

# Confirm rpl_semi_sync_master_trace_level and rpl_semi_sync_slave_trace_level

# are dead sysvars.

#

# Source review: both feed Trace::m_trace_level (sql/semisync.h) via

# set_trace_level(), on the master and slave semisync objects respectively.

# Grepping all of sql/*.cc and sql/*.h finds no read of m_trace_level, and no

# test anywhere against any of the four Trace::k_trace_* bitmask constants

# (k_trace_general/detail/net_wait/function, sql/semisync.cc). The variable

# is write-only.

#

# This test proves it live: for each of the master and slave sides, capture

# the "semisync" DBUG trace produced by an identical batch of transactions

# once at trace_level=0 and once at trace_level=ULONG_MAX, then diff the two

# captures after normalizing away everything that legitimately varies

# between two different batches of transactions (timestamps, thread ids,

# binlog positions, GTID components -- i.e. every number). If trace_level

# had any effect, the normalized captures would differ (extra/missing

# lines, different message text). They don't.

#

# If this test ever starts failing, someone has wired trace_level up for

# real -- update or remove it rather than "fixing" it blindly.

#

--source include/have_debug.inc

--source include/have_innodb.inc

--source include/master-slave.inc

--let $trace_dir= $MYSQLTEST_VARDIR/tmp

--connection master

CREATE TABLE t1 (a INT PRIMARY KEY, b INT) ENGINE=InnoDB;

SET GLOBAL rpl_semi_sync_master_enabled= 1;

# Long timeout: with a real, connected, acking slave this is never actually

# waited out, but keeps the test robust against any scheduling jitter.

SET GLOBAL rpl_semi_sync_master_timeout= 3600000;

--connection slave

# The IO thread must reconnect for semi-sync to actually be negotiated --

# flipping the flag alone does not renegotiate an already-connected thread.

--source include/stop_slave.inc

SET GLOBAL rpl_semi_sync_slave_enabled= 1;

--source include/start_slave.inc

--connection master

--let $status_var= Rpl_semi_sync_master_clients

--let $status_var_value= 1

--source include/wait_for_status_var.inc

--let $wait_condition= SELECT VARIABLE_VALUE = 'ON' FROM information_schema.global_status WHERE VARIABLE_NAME = 'RPL_SEMI_SYNC_MASTER_STATUS'

--source include/wait_condition.inc

--echo #

--echo # --- Master: rpl_semi_sync_master_trace_level, 0 vs ULONG_MAX ---

--echo #

--let $mtrace_a= $trace_dir/semisync_master_trace_a.trc

--let $mtrace_b= $trace_dir/semisync_master_trace_b.trc

--let $mtrace_a_norm= $trace_dir/semisync_master_trace_a.norm

--let $mtrace_b_norm= $trace_dir/semisync_master_trace_b.norm

--connection master

--disable_query_log

SET GLOBAL rpl_semi_sync_master_trace_level= 0;

--eval SET GLOBAL debug_dbug= 'd,semisync:O,$mtrace_a'

INSERT INTO t1 VALUES (1,1);

INSERT INTO t1 VALUES (2,2);

INSERT INTO t1 VALUES (3,3);

SET GLOBAL debug_dbug= '';

SET GLOBAL rpl_semi_sync_master_trace_level= 18446744073709551615;

--enable_query_log

SELECT @@GLOBAL.rpl_semi_sync_master_trace_level;

--disable_query_log

--eval SET GLOBAL debug_dbug= 'd,semisync:O,$mtrace_b'

INSERT INTO t1 VALUES (4,4);

INSERT INTO t1 VALUES (5,5);

INSERT INTO t1 VALUES (6,6);

SET GLOBAL debug_dbug= '';

SET GLOBAL rpl_semi_sync_master_trace_level= 32;

--enable_query_log

# Guard against a false pass: fail loudly (nonzero exit) if tracing somehow

# didn't produce anything, rather than silently "succeeding" on empty files.

--exec test -s $mtrace_a

--exec test -s $mtrace_b

--exec sed -E 's/[0-9]+/N/g' $mtrace_a | sort > $mtrace_a_norm

--exec sed -E 's/[0-9]+/N/g' $mtrace_b | sort > $mtrace_b_norm

--echo # silence below = identical trace content at trace_level=0 and ULONG_MAX

--diff_files $mtrace_a_norm $mtrace_b_norm

--remove_file $mtrace_a

--remove_file $mtrace_b

--remove_file $mtrace_a_norm

--remove_file $mtrace_b_norm

--echo #

--echo # --- Slave: rpl_semi_sync_slave_trace_level, 0 vs ULONG_MAX ---

--echo #

--let $strace_a= $trace_dir/semisync_slave_trace_a.trc

--let $strace_b= $trace_dir/semisync_slave_trace_b.trc

--let $strace_a_norm= $trace_dir/semisync_slave_trace_a.norm

--let $strace_b_norm= $trace_dir/semisync_slave_trace_b.norm

--connection slave

--disable_query_log

SET GLOBAL rpl_semi_sync_slave_trace_level= 0;

--eval SET GLOBAL debug_dbug= 'd,semisync:O,$strace_a'

--enable_query_log

--connection master

--disable_query_log

INSERT INTO t1 VALUES (7,7);

INSERT INTO t1 VALUES (8,8);

INSERT INTO t1 VALUES (9,9);

--enable_query_log

--sync_slave_with_master

--connection slave

--disable_query_log

SET GLOBAL debug_dbug= '';

SET GLOBAL rpl_semi_sync_slave_trace_level= 18446744073709551615;

--enable_query_log

SELECT @@GLOBAL.rpl_semi_sync_slave_trace_level;

--disable_query_log

--eval SET GLOBAL debug_dbug= 'd,semisync:O,$strace_b'

--enable_query_log

--connection master

--disable_query_log

INSERT INTO t1 VALUES (10,10);

INSERT INTO t1 VALUES (11,11);

INSERT INTO t1 VALUES (12,12);

--enable_query_log

--sync_slave_with_master

--connection slave

--disable_query_log

SET GLOBAL debug_dbug= '';

SET GLOBAL rpl_semi_sync_slave_trace_level= 32;

--enable_query_log

--exec test -s $strace_a

--exec test -s $strace_b

--exec sed -E 's/[0-9]+/N/g' $strace_a | sort > $strace_a_norm

--exec sed -E 's/[0-9]+/N/g' $strace_b | sort > $strace_b_norm

--echo # silence below = identical trace content at trace_level=0 and ULONG_MAX

--diff_files $strace_a_norm $strace_b_norm

--remove_file $strace_a

--remove_file $strace_b

--remove_file $strace_a_norm

--remove_file $strace_b_norm

--connection master

DROP TABLE t1;

SET GLOBAL rpl_semi_sync_master_enabled= 0;

SET GLOBAL rpl_semi_sync_master_timeout= default;

--connection slave

--source include/stop_slave.inc

SET GLOBAL rpl_semi_sync_slave_enabled= 0;

--source include/start_slave.inc

--source include/rpl_end.inc