database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-29 05:21:33 +03:00
Code Activity

MDEV-14505 - Threads_running becomes scalability bottleneck

Browse Source 
Instead of updating global counter, calculate Threads_running on the fly.
All threads having command != COM_SLEEP are included.

Behaviour changes:

Previously SHOW STATUS and SHOW GLOBAL STATUS returned the same values
representing global status. Now SHOW STATUS always returns 1 indicating that
current session has 1 thread running.

Previously only threads that were executing dispatch_command() or running events
were accounted by Threads_running. Now it is rough equivalent of
SELECT COUNT(*) FROM INFORMATION_SCHEMA.PROCESSLIST WHERE state!='Sleep'
This commit is contained in:
Sergey Vojtovich
2017-12-12 22:53:38 +04:00
parent 751e0f6b1e
commit 159a6c2e60
10 changed files with 44 additions and 23 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
sql/sql_parse.cc
View File

@ -1550,9 +1550,6 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
"<?>")));
bool drop_more_results= 0;
if (!is_com_multi)
inc_thread_running();
/* keep it withing 1 byte */
compile_time_assert(COM_END == 255);
@ -2410,10 +2407,8 @@ com_multi_end:
thd->m_digest= NULL;
if (!is_com_multi)
{
dec_thread_running();
thd->packet.shrink(thd->variables.net_buffer_length); // Reclaim some memory
}
thd->reset_kill_query(); /* Ensure that killed_errmsg is released */
free_root(thd->mem_root,MYF(MY_KEEP_PREALLOC));