Bug #82807 "set persist general_log=1" does not resume on restart.
Submitted: 31 Aug 2016 5:23 Modified: 4 Oct 2016 22:43
Reporter: Giuseppe Maxia (OCA) Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Server: Options Severity:S2 (Serious)
Version:8.0.0, 8.0.1 OS:Ubuntu
Assigned to: CPU Architecture:Any

[31 Aug 2016 5:23] Giuseppe Maxia
Description:
This statement:

set persist general_log=on;

generates an entry in $DATADIR/mysqld-auto.cnf

{ "mysql_server": {"general_log": "ON" } }

However, when we restart the server, the variable general_log is still 0.

mysql [localhost] {msandbox} ((none)) > select @@general_log;
+---------------+
| @@general_log |
+---------------+
|             0 |
+---------------+
1 row in set (0.00 sec)

If we manually change the JSON file contents as follows:
{ "mysql_server": {"general_log": "1" } }

then the variable is enabled after a restart:
mysql [localhost] {msandbox} ((none)) > select @@general_log;
+---------------+
| @@general_log |
+---------------+
|             1 |
+---------------+
1 row in set (0.00 sec)

How to repeat:
see above
[31 Aug 2016 6:08] Umesh Shastry
Hello Giuseppe,

Thank you for the report.
Verified as described with the 8.0 daily build.

Thanks,
Umesh
[31 Aug 2016 6:08] Umesh Shastry
--

rm -rf 82806
bin/mysqld  --initialize-insecure --basedir=/export/umesh/server/binaries/Trunk/mysql-advanced-8.0 --datadir=/export/umesh/server/binaries/Trunk/mysql-advanced-8.0/82806 -v
bin/mysqld --basedir=/export/umesh/server/binaries/Trunk/mysql-advanced-8.0 --datadir=/export/umesh/server/binaries/Trunk/mysql-advanced-8.0/82806 --core-file --socket=/tmp/mysql_ushastry.sock  --port=3306 --log-error=/export/umesh/server/binaries/Trunk/mysql-advanced-8.0/82806/log.err 2>&1 &

[umshastr@hod03]/export/umesh/server/binaries/Trunk/mysql-advanced-8.0: bin/mysql -uroot -S /tmp/mysql_ushastry.sock
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 8.0.1-dmr-enterprise-commercial-advanced MySQL Enterprise Server - Advanced Edition (Commercial)

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> set persist general_log=on;
Query OK, 0 rows affected (0.01 sec)

mysql> SYSTEM cat 82806/mysqld-auto.cnf
{ "mysql_server": {"general_log": "ON" } }
mysql>
mysql> show variables like 'general_log';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| general_log   | ON    |
+---------------+-------+
1 row in set (0.01 sec)

mysql> \q
Bye
[umshastr@hod03]/export/umesh/server/binaries/Trunk/mysql-advanced-8.0: bin/mysqladmin -uroot -S /tmp/mysql_ushastry.sock shutdown
[umshastr@hod03]/export/umesh/server/binaries/Trunk/mysql-advanced-8.0: bin/mysqld --basedir=/export/umesh/server/binaries/Trunk/mysql-advanced-8.0 --datadir=/export/umesh/server/binaries/Trunk/mysql-advanced-8.0/82806 --core-file --socket=/tmp/mysql_ushastry.sock  --port=3306 --log-error=/export/umesh/server/binaries/Trunk/mysql-advanced-8.0/82806/log.err 2>&1 &
[umshastr@hod03]/export/umesh/server/binaries/Trunk/mysql-advanced-8.0: bin/mysql -uroot -S /tmp/mysql_ushastry.sock                                                                              Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 8.0.1-dmr-enterprise-commercial-advanced MySQL Enterprise Server - Advanced Edition (Commercial)

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show variables like 'general_log';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| general_log   | OFF   |
+---------------+-------+
1 row in set (0.00 sec)

mysql> \q
Bye
[31 Aug 2016 6:19] Umesh Shastry
--P_S's variables_info table confirms the settings though

mysql> SELECT VARIABLE_NAME FROM variables_info  WHERE VARIABLE_SOURCE = 'PERSISTED'  ORDER BY VARIABLE_NAME;
+---------------+
| VARIABLE_NAME |
+---------------+
| general_log   |
+---------------+
1 row in set (0.00 sec)
[31 Aug 2016 6:23] Giuseppe Maxia
True: the P_S table says that it's persisted, but the general log is not enabled.
[4 Oct 2016 22:43] Paul Dubois
Posted by developer:
 
Noted in 8.0.1 changelog.

Using SET PERSIST with the global_log system variable was
ineffective.
[5 Oct 2016 1:51] tsubasa tanaka
> Using SET PERSIST with the global_log system variable was
> ineffective.

What's "global_log" ? A typo of "general_log" ?