Bug #73117 thread-concurrency in my.cnf should not prohibit server start

• Submitted: 25 Jun 2014 17:50
• Modified: 31 Jan 2020 13:43
• Reporter: Morgan Tocker
• Status: Won't fix
• Category: MySQL Server: Compiling
• Severity: S4 (Feature request)
• Version: 5.7
• OS: Any
• CPU Architecture: Any

[25 Jun 2014 17:50] Morgan Tocker

Description:
In MySQL 5.7, the option thread-concurrency has been removed.  This is a common option that many configuration files in the wild will have present.

Users upgrading and keeping their old configuration files may find the server no longer starts.

How to repeat:
In MySQL 5.6.19:
Setting thread-concurrency is deprecated, but I actually receive no warning in my error log when setting it:

140625 10:47:05 mysqld_safe Starting mysqld daemon with databases from /Users/morgo/sandboxes/msb_5_6_19/data
2014-06-25 10:47:05 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2014-06-25 10:47:05 66868 [Warning] Setting lower_case_table_names=2 because file system for /Users/morgo/sandboxes/msb_5_6_19/data/ is case insensitive
2014-06-25 10:47:05 66868 [Note] Plugin 'FEDERATED' is disabled.
2014-06-25 10:47:05 66868 [Note] InnoDB: Using atomics to ref count buffer pool pages
2014-06-25 10:47:05 66868 [Note] InnoDB: The InnoDB memory heap is disabled
2014-06-25 10:47:05 66868 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2014-06-25 10:47:05 66868 [Note] InnoDB: Compressed tables use zlib 1.2.3
2014-06-25 10:47:05 66868 [Note] InnoDB: Not using CPU crc32 instructions
2014-06-25 10:47:05 66868 [Note] InnoDB: Initializing buffer pool, size = 128.0M
2014-06-25 10:47:05 66868 [Note] InnoDB: Completed initialization of buffer pool
2014-06-25 10:47:05 66868 [Note] InnoDB: Highest supported file format is Barracuda.
2014-06-25 10:47:06 66868 [Note] InnoDB: 128 rollback segment(s) are active.
2014-06-25 10:47:06 66868 [Note] InnoDB: Waiting for purge to start
2014-06-25 10:47:06 66868 [Note] InnoDB: 5.6.19 started; log sequence number 7246703349
2014-06-25 10:47:06 66868 [Note] Server hostname (bind-address): '127.0.0.1'; port: 5619
2014-06-25 10:47:06 66868 [Note]   - '127.0.0.1' resolves to '127.0.0.1';
2014-06-25 10:47:06 66868 [Note] Server socket created on IP: '127.0.0.1'.
2014-06-25 10:47:06 66868 [Note] Event Scheduler: Loaded 0 events
2014-06-25 10:47:06 66868 [Note] /Users/morgo/Documents/mysql-installs/5.6.19/bin/mysqld: ready for connections.
Version: '5.6.19'  socket: '/var/folders/j_/yn_r8b8d531839w0jkzglz500000gn/T//mysql_sandbox5619.sock'  port: 5619  MySQL Community Server (GPL)

In MySQL 5.7.4:
2014-06-25T17:35:42.115750Z 0 [ERROR] unknown variable 'thread-concurrency=10'
2014-06-25T17:35:42.115774Z 0 [ERROR] Aborting

Suggested fix:
Since this option offers no major change in behavior from previous versions, I would like to propose a less severe error.  For example:

2014-05-14T17:03:31.258417Z 0 [Warning] Option 'thread-concurrency' has been removed from MySQL and will not apply.

At the same time, mysqld should still be permitted to start.