Bug#31327337: SUBSYSTEM NAME FOR SEMISYNC ERRORS IS [SERVER]

Messages from semi-sync replication appeared in the error-log
with a subsystem tag of "Server", rather than the expected
"Repl". This was a result of a fault in the per-subtree set-up
of semi-sync.

Messages from semi-sync, such as MY-011171
(ER_SEMISYNC_STOP_BINLOG_DUMP_TO_SLAVE) are now correctly
issued with a subsystem tag of "Repl".

This incidently is a great example of how easy testing for
error-log contents is since the addition of the table
performance_schema.error_log (WL#13681):

> SELECT subsystem, error_code
    FROM performance_schema.error_log
   WHERE error_code="MY-011170" LIMIT 1;

subsystem      error_code
Repl   MY-011170

Change-Id: I5ae349338c46d75d7e7d7641cd8bff6404b95933

Author: Tatiana Azundris Nuernberg

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

@@ -391,6 +391,11 @@ 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	2
+select subsystem, error_code
+from performance_schema.error_log
+where error_code="MY-011170" limit 1;
+subsystem	error_code
+Repl	MY-011170
 #
 # Test semi-sync slave connect to non-semi-sync master
 #

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

@@ -525,6 +525,11 @@ 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';
 
+# Bug#31327337: SUBSYSTEM NAME FOR SEMISYNC ERRORS IS [SERVER] - pt2
+select subsystem, error_code
+  from performance_schema.error_log
+ where error_code="MY-011170" limit 1;
+
 --echo #
 --echo # Test semi-sync slave connect to non-semi-sync master
 --echo #

plugin/semisync/CMakeLists.txt

@@ -1,4 +1,4 @@
-# Copyright (c) 2006, 2019, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2006, 2020, Oracle and/or its affiliates.
 # 
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License, version 2.0,
@@ -21,7 +21,7 @@
 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
 
 ADD_DEFINITIONS(-DMYSQL_SERVER)
-ADD_DEFINITIONS(-DLOG_SUBSYS_TAG="Repl")
+ADD_DEFINITIONS(-DLOG_SUBSYSTEM_TAG="Repl")
 ADD_DEFINITIONS(-DLOG_COMPONENT_TAG="semisync")
 
 MYSQL_ADD_PLUGIN(semisync_master