Details
-
Bug
-
Status: Closed (View Workflow)
-
Major
-
Resolution: Fixed
-
10.1
-
None
-
10.1.17-1, 10.1.18, 10.1.30
Description
table_open_cache is supposed to be adjusted (decreased) automatically if system limit on open files does not allow the desired value. It works all right until we also provide open-files-limit option. The option itself does not really do much (as explained here, for example: https://bugs.mysql.com/bug.php?id=34870), but it somehow affects the adjustment; so, table_open_cache can end up with a higher value than the system allows, which leads to obvious problems.
MySQL 5.6 and 5.7 are not affected.
10.1 and 10.2 are affected the most, because default value for table_open_cache there is 2000, and it remains such in the described scenario.
10.0 is also affected, but since the default value there is 400, it is less of a problem.
Example:
$ ulimit -n
|
1024
|
|
Server started with all defaults, no extra options - OK |
+-----------------------+-------------------+--------------------+
|
| @@version | @@max_connections | @@table_open_cache |
|
+-----------------------+-------------------+--------------------+
|
| 10.1.15-MariaDB-debug | 151 | 431 |
|
+-----------------------+-------------------+--------------------+
|
|
Server started with all defaults and --open-files-limit=1024 - Problem |
+-----------------------+-------------------+--------------------+
|
| @@version | @@max_connections | @@table_open_cache |
|
+-----------------------+-------------------+--------------------+
|
| 10.1.15-MariaDB-debug | 151 | 2000 |
|
+-----------------------+-------------------+--------------------+
|
|
MySQL servers started with all defaults and --open-files-limit=1024 - OK |
+--------------+-------------------+--------------------+
|
| @@version | @@max_connections | @@table_open_cache |
|
+--------------+-------------------+--------------------+
|
| 5.6.31-debug | 151 | 431 |
|
+--------------+-------------------+--------------------+
|
+--------------+-------------------+--------------------+
|
| @@version | @@max_connections | @@table_open_cache |
|
+--------------+-------------------+--------------------+
|
| 5.7.13-debug | 151 | 431 |
|
+--------------+-------------------+--------------------+
|
Consequences of the problem are very easily reproducible on 10.1 with MTR, because MTR quite conveniently a) sets system limit to 1024 for any platform, and b) has open-files-limit=1024 in the default config template.
|
MTR test case |
--let $cnt= 2000
|
|
|
while ($cnt)
|
{
|
eval CREATE TABLE t_$cnt (i INT) ENGINE=MyISAM; |
eval INSERT INTO t_$cnt VALUES (1); |
--dec $cnt |
}
|
....
|
INSERT INTO t_1518 VALUES (1);
|
CREATE TABLE t_1517 (i INT) ENGINE=MyISAM;
|
INSERT INTO t_1517 VALUES (1);
|
CREATE TABLE t_1516 (i INT) ENGINE=MyISAM;
|
bug.t1 [ fail ]
|
Test ended at 2016-06-25 21:15:21
|
|
|
CURRENT_TEST: bug.t1
|
mysqltest: At line 8: query 'CREATE TABLE t_$cnt (i INT) ENGINE=MyISAM' failed: 1005: Can't create table `test`.`t_1516` (errno: 24 "Too many open files")
|
Attachments
Issue Links
- duplicates
-
-
- Closed
-