Hello,

I am counter-checking the mysqlreport "fork" i am maintening (https://mariadb.atlassian.net/browse/MDEV-573) so it could be included in Maria 10 before GA, i am actually unsure that i am checking correctly the Threadpool usage.


For these stats (with thread_pool_max_threads=1200 and thread_handling=pool-of-threads) :
+------------------------------------------+---------+
| Variable_name                            | Value   |
+------------------------------------------+---------+
| Threadpool_idle_threads                  | 47      |
| Threadpool_threads                       | 52      |
| Threads_cached                           | 0       |
| Threads_connected                        | 19      |
| Threads_created                          | 599771  |
| Threads_running                          | 6       |
+------------------------------------------+---------+
The actual output is :
__ Threads ___________________________________________
Running             6 of     24
Created       599.77k       0.2/s
Slow                0         0/s
Threadpool         98 of   1200     %Used:   8.17
  Running          52 of   1200  %Running:   4.33
  Idle             46 of   1200     %Idle:   3.83

The formulae used are :
Threadpool    $stats{'Threadpool_threads'} + $stats{'Threadpool_idle_threads'})   of  $vars{'thread_pool_max_threads'}    %Used: percentage( 
($stats{'Threadpool_threads'} + $stats{'Threadpool_idle_threads'}) / 
$vars{'thread_pool_max_threads'}
    Running   $stats{'Threadpool_threads'}  of  
$vars{'thread_pool_max_threads'}    %Running: 
percentage($stats{'Threadpool_threads'} / 
$vars{'thread_pool_max_threads'})
    Idle     $stats{'Threadpool_idle_threads'}  of  
$vars{'thread_pool_max_threads'}    %Idle: 
percentage($stats{'Threadpool_idle_threads'} / 
$vars{'thread_pool_max_threads'})


Is the Threadpool usage calculation right or should only the Threadpool_threads status be used?
What is the meaning of the Threads_connected value when the threadpool is used?


Regards.