Adjust table_open_cache to avoid getting error 24 (too many open files)

MDEV--15609 engines/funcs.crash_manytables_number crashes with error 24
           (too many open files)
MDEV-10286  Adjustment of table_open_cache according to system limits
            does not work when open-files-limit option is provided

Fixed by adjusting tc_size downwards if there is not enough file
descriptors to use.

Other changes:
- Ensure that there is 30 (was 10) extra file descriptors for other usage
- Decrease TABLE_OPEN_CACHE_MIN to 200 as it's better to have a smaller
  table cache than getting error 24
- Increase minimum of max_connections and table_open_cache from 1 to 10
  as 1 is not usable for any real application, only for testing.

Author: montywi

mysql-test/mysql-test-run.pl

@@ -4458,6 +4458,7 @@ ($$)
      qr|SSL error: Failed to set ciphers to use|,
      qr/Plugin 'InnoDB' will be forced to shutdown/,
      qr|Could not increase number of max_open_files to more than|,
+     qr|Changed limits: max_open_files|,
      qr/InnoDB: Error table encrypted but encryption service not available.*/,
      qr/InnoDB: Could not find a valid tablespace file for*/,
      qr/InnoDB: Tablespace open failed for*/,

mysql-test/r/connect.result

@@ -147,7 +147,7 @@ drop table t1;
 CREATE USER mysqltest_u1@localhost;
 GRANT USAGE ON *.* TO mysqltest_u1@localhost;
 
-SET GLOBAL max_connections = 3;
+SET GLOBAL max_connections = 10;
 SET GLOBAL event_scheduler = ON;
 
 # -- Waiting for Event Scheduler to start...
@@ -191,6 +191,13 @@ event_scheduler
 mysqltest_u1
 mysqltest_u1
 mysqltest_u1
+mysqltest_u1
+mysqltest_u1
+mysqltest_u1
+mysqltest_u1
+mysqltest_u1
+mysqltest_u1
+mysqltest_u1
 root
 
 # -- Resetting variables...

mysql-test/r/mdev375.result

@@ -1,5 +1,5 @@
 SET GLOBAL log_warnings=4;
-SET GLOBAL max_connections=2;
+SET GLOBAL max_connections=10;
 SELECT 1;
 1
 1

mysql-test/r/myisam.result

@@ -1906,9 +1906,9 @@ DROP TABLE t1;
 #
 # BUG#48438 - crash with error in unioned query against merge table and view...
 #
-SET GLOBAL table_open_cache=3;
+SET GLOBAL table_open_cache=10;
 CREATE TABLE t1(a INT);
-SELECT 1 FROM t1 AS a1, t1 AS a2, t1 AS a3, t1 AS a4 FOR UPDATE;
+SELECT 1 FROM t1 AS a1, t1 AS a2, t1 AS a3, t1 AS a4, t1 AS a5, t1 AS a6, t1 AS a7, t1 AS a8, t1 AS a9, t1 AS a10, t1 AS a11 FOR UPDATE;
 1
 SELECT TABLE_ROWS, DATA_LENGTH FROM INFORMATION_SCHEMA.TABLES
 WHERE TABLE_SCHEMA='test' AND TABLE_NAME='t1';

mysql-test/r/mysqld--help,win.rdiff

@@ -121,10 +121,10 @@
  sync-relay-log 10000
  sync-relay-log-info 10000
  sysdate-is-now FALSE
--table-cache 431
+-table-cache 421
 +table-cache 2000
  table-definition-cache 400
--table-open-cache 431
+-table-open-cache 421
 +table-open-cache 2000
  tc-heuristic-recover OFF
  thread-cache-size 0

mysql-test/r/mysqld--help.result

@@ -1438,9 +1438,9 @@ sync-master-info 10000
 sync-relay-log 10000
 sync-relay-log-info 10000
 sysdate-is-now FALSE
-table-cache 431
+table-cache 421
 table-definition-cache 400
-table-open-cache 431
+table-open-cache 421
 tc-heuristic-recover OFF
 thread-cache-size 0
 thread-pool-idle-timeout 60

mysql-test/r/sp.result

@@ -7946,7 +7946,7 @@ CLOSE cur1;
 end|
 set @tmp_toc= @@table_open_cache;
 set @tmp_tdc= @@table_definition_cache;
-set global table_open_cache=1;
+set global table_open_cache=10;
 set global table_definition_cache=1;
 Warnings:
 Warning	1292	Truncated incorrect table_definition_cache value: '1'

mysql-test/r/variables.result

@@ -748,10 +748,10 @@ Warnings:
 Warning	1292	Truncated incorrect table_open_cache value: '-1'
 SHOW VARIABLES LIKE 'table_open_cache';
 Variable_name	Value
-table_open_cache	1
+table_open_cache	10
 SELECT * FROM INFORMATION_SCHEMA.SESSION_VARIABLES WHERE VARIABLE_NAME LIKE 'table_open_cache';
 VARIABLE_NAME	VARIABLE_VALUE
-TABLE_OPEN_CACHE	1
+TABLE_OPEN_CACHE	10
 SET GLOBAL table_open_cache=DEFAULT;
 set character_set_results=NULL;
 select ifnull(@@character_set_results,"really null");

mysql-test/suite/perfschema/r/hostcache_ipv4_max_con.result

@@ -525,7 +525,7 @@ COUNT_UNKNOWN_ERRORS	0
 FIRST_ERROR_SEEN	set
 LAST_ERROR_SEEN	set
 set global max_user_connections = 0;
-set global max_connections = 3;
+set global max_connections = 10;
 flush user_resources;
 select "Con4a is alive";
 Con4a is alive

mysql-test/suite/perfschema/r/hostcache_ipv6_max_con.result

@@ -525,7 +525,7 @@ COUNT_UNKNOWN_ERRORS	0
 FIRST_ERROR_SEEN	set
 LAST_ERROR_SEEN	set
 set global max_user_connections = 0;
-set global max_connections = 3;
+set global max_connections = 10;
 flush user_resources;
 select "Con4a is alive";
 Con4a is alive