Bug #21978 'flush_time' value set for 1800 sec. on Non Win9x/Me installs by default

• Submitted: 1 Sep 2006 22:13
• Modified: 5 Dec 2007 18:55
• Reporter: Matthew Montgomery
• Status: Verified
• Category: MySQL Server: Options
• Severity: S3 (Non-critical)
• Version: 4.0.18, 5.0, 6.0.10, 5.5
• OS: Windows (Windows 2000)
• CPU Architecture: Any
• Tags: flush_time, open_files_limit, performance, table_open_cache, windows

[1 Sep 2006 22:13] Matthew Montgomery

Description:
Hello,

According to the documentation for the variable 'flush_time', http://dev.mysql.com/doc/refman/5.0/en/server-system-variables.html

"We recommend that this option be used only on Windows 9x or Me, or on systems with minimal resources."

This value is still set to 1800 on recent installs of MySQL on Windows2000 and later.

It should probably be set to 0, as it is on *nix installs to avoid undue flushes of the table_cache.

Thanks,

How to repeat:
-NA-

Suggested fix:
flush_time, should probably be set to 0 on non Windows9x/ME installs, as it is on *nix installs to avoid undue flushes of the table_cache.

[2 Sep 2006 11:31] Valeriy Kravchuk

Verified just as described. Default value for flush_time on Windows is still 1800 (0 on Linux).

[5 Dec 2009 7:45] MySQL Verification Team

in light of new information, and a new decade, please retriage.

in all versions of mysql on windows where bug #24509 (2048 file descriptor limit on windows needs increasing) will be fixed, we must ensure that flush_time variable is set to 0 by default.  currently it is default 1800 seconds which means every half and hour all tables are flushed.

mysql> show global variables like 'open_files_limit';
+------------------+-------+
| Variable_name    | Value |
+------------------+-------+
| open_files_limit | 18048 |
+------------------+-------+
1 row in set (0.03 sec)

mysql> show global variables like 'flush_time';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| flush_time    | 1800  |
+---------------+-------+
1 row in set (0.00 sec)

mysql> select version();
+------------------------+
| version()              |
+------------------------+
| 6.0.10-alpha-community |
+------------------------+
1 row in set (0.02 sec)