Hi Sergei, The only reason is there were minor requests to make it tunable. It is easier to convert read-only var to command line option. If we know for sure that we won't do it, I can make it status var instead. Thanks, Sergey On Thu, Oct 26, 2017 at 07:15:42PM +0200, Sergei Golubchik wrote:

Hi, Sergey!

Looks ok, thanks. Just one question:

On Aug 10, Sergey Vojtovich wrote:

...

revision-id: 9145b7dd11a0e95016304e53acf306daac323580 (mariadb-10.3.0-49-g9145b7d) parent(s): 63ad4fe5bbe77fe17ab441fcce0106bdee9b618d committer: Sergey Vojtovich timestamp: 2017-08-10 15:45:03 +0400 message:

MDEV-11153 - Introduce status variables for table cache monitoring and tuning

Status variables added: Table_open_cache_hits, Table_open_cache_misses, Table_open_cache_overflows.

System variables added: table_open_cache_active_instances (read-only).

diff --git a/sql/sys_vars.cc b/sql/sys_vars.cc index e89dd47..92721b6 100644 --- a/sql/sys_vars.cc +++ b/sql/sys_vars.cc @@ -3219,6 +3219,12 @@ static Sys_var_ulong Sys_table_cache_size( BLOCK_SIZE(1), NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(0), ON_UPDATE(fix_table_open_cache));

+static Sys_var_uint Sys_table_cache_active_instances( + "table_open_cache_active_instances", + "Number of active table cache instances", + READ_ONLY GLOBAL_VAR(tc_active_instances), NO_CMD_LINE, + VALID_RANGE(1, 64), DEFAULT(1), BLOCK_SIZE(1));

Why did you do it as a sysvar, not as a status variable?

Regards, Sergei Chief Architect MariaDB and security@mariadb.org