The threads table provides information about
threads running in the NDB kernel.
The threads table contains the following
columns:
node_idID of the node where the thread is running
thr_noThread ID (specific to this node)
thread_nameThread name (type of thread)
thread_descriptionThread (type) description
Notes
Sample output from a 2-node example cluster, including thread descriptions, is shown here:
mysql> SELECT * FROM threads;
+---------+--------+-------------+------------------------------------------------------------------+
| node_id | thr_no | thread_name | thread_description |
+---------+--------+-------------+------------------------------------------------------------------+
| 5 | 0 | main | main thread, schema and distribution handling |
| 5 | 1 | rep | rep thread, asynch replication and proxy block handling |
| 5 | 2 | ldm | ldm thread, handling a set of data partitions |
| 5 | 3 | recv | receive thread, performing receive and polling for new receives |
| 6 | 0 | main | main thread, schema and distribution handling |
| 6 | 1 | rep | rep thread, asynch replication and proxy block handling |
| 6 | 2 | ldm | ldm thread, handling a set of data partitions |
| 6 | 3 | recv | receive thread, performing receive and polling for new receives |
+---------+--------+-------------+------------------------------------------------------------------+
8 rows in set (0.01 sec)
It is also possible to set either of the
ThreadConfig arguments
main or rep to 0 while
keeping the other at 1, in which case the thread name is
main_rep and its description is main
and rep thread, schema, distribution, proxy block and asynch
replication handling. You can also set both
main and rep to 0, in
which case the name of the resulting thread is shown in this
table as main_rep_recv, and its description
is main, rep and recv thread, schema, distribution,
proxy block and asynch replication handling and handling receive
and polling for new receives.