Every time I restart mysql, I see the following in the error logs immediately after the restart

Question

2017-06-29T17:38:11.740837Z 0 [Note] Event Scheduler: Loaded 0 events
2017-06-29T17:38:11.741470Z 0 [Note] /usr/sbin/mysqld: ready for connections.
Version: '5.7.18-0ubuntu0.16.04.1'  socket: '/var/run/mysqld/mysqld.sock'  port: 3306  (Ubuntu)
2017-06-29T17:38:11.741496Z 0 [Note] Executing 'SELECT * FROM INFORMATION_SCHEMA.TABLES;' to get a list of tables using the deprecated partition engine. You may use the startup option '--disable-partition-engine-check' to skip this check. 
2017-06-29T17:38:11.741511Z 0 [Note] Beginning of list of non-natively partitioned tables
2017-06-29T17:38:11.882383Z 0 [Note] End of list of non-natively partitioned tables
2017-06-29T17:38:11.889889Z 5 [Note] Access denied for user 'root'@'localhost' (using password: NO)

I am on Ubuntu 16.04 LTS. I do not know what is running the SELECT or what is trying to login as the root user. I do not suspect malware as these are brand new installed machines. These lines come instantly after each restart.

How do I further debug what is running the SELECT and what is being denied access for root@localhost? I have turned off all of my processes.

Thanks!

Answer 1

You have MySQL 5.7.18. Note from Reference Manual Chapter 22 Partitioning:

As of MySQL 5.7.17, the generic partitioning handler in the MySQL server is deprecated, and is removed in MySQL 8.0, when the storage engine used for a given table is expected to provide its own (“native”) partitioning handler. Currently, only the InnoDB and NDB storage engines do.

Use of tables with nonnative partitioning results in an ER_WARN_DEPRECATED_SYNTAX warning. Also, the server performs a check at startup to identify tables that use nonnative partitioning; for any found, the server writes a message to its error log.

To disable this check, use the --disable-partition-engine-check option.

To prepare for migration to MySQL 8.0, any table with nonnative partitioning should be changed to use an engine that provides native partitioning, or be made nonpartitioned. For example, to change a table to InnoDB, execute this statement:

ALTER TABLE table_name ENGINE = INNODB;

Based on the next two lines it looks like you don't have these tables, so you probably don't have to worry about this issue, unless the unsuccessful root login is related to that test. If you want to be sure, log in as root and execute the query from the test manually, i.e. (tables with other engines):

SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE ENGINE NOT IN ('INNODB', 'NDB');

Whether you want to use the --disable-partition-engine-check option after this manual test is up to you. However, it's just a couple of log lines and it might be good to stay informed if someone adds such tables, ever, until it's time to upgrade to MySQL 8.0.

Answer 2

The messages tell you exactly what is going on:

2017-06-29T17:38:11.741496Z 0 [Note] Executing 'SELECT * FROM INFORMATION_SCHEMA.TABLES;' to get a list of tables using the deprecated partition engine. You may use the startup option '--disable-partition-engine-check' to skip this check. 

In other words, mysql is itself executing 'SELECT * FROM INFORMATION_SCHEMA.TABLES;'. It does that in order to get a list of tables using the deprecated partition engine.

If you want it not to do that, you can use the startup option --disable-partition-engine-check to skip this check.