Spec-Zone .ru
спецификации, руководства, описания, API
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Spec-Zone .ru
спецификации, руководства, описания, API
|
The threadstat table provides a rough snapshot of statistics for threads running in
the NDB kernel.
The following table provides information about the columns in the threadstat table.
For each column, the table shows the name, data type, and a brief description. Additional information can be
found in the notes following the table.
| Column Name | Type | Remarks |
|---|---|---|
node_id |
integer | Node ID |
thr_no |
integer | Thread ID |
thr_nm |
string | Thread name |
c_loop |
string | Number of loops in main loop |
c_exec |
string | Number of signals executed |
c_wait |
string | Number of times waiting for additional input |
c_l_sent_prioa |
integer | Number of priority A signals sent to own node |
c_l_sent_priob |
integer | Number of priority B signals sent to own node |
c_r_sent_prioa |
integer | Number of priority A signals sent to remote node |
c_r_sent_priob |
integer | Number of priority B signals sent to remote node |
os_tid |
integer | OS thread ID |
os_now |
integer | OS time (ms) |
os_ru_utime |
integer | OS user CPU time (µs) |
os_ru_stime |
integer | OS system CPU time (µs) |
os_ru_minflt |
integer | OS page reclaims (soft page faults) |
os_ru_majflt |
integer | OS page faults (hard page faults) |
os_ru_nvcsw |
integer | OS voluntary context switches |
os_ru_nivcsw |
integer | OS involuntary context switches |
os_time uses the system gettimeofday() call.
The values of the os_ru_utime, os_ru_stime, os_ru_minflt, os_ru_majflt, os_ru_nvcsw,
and os_ru_nivcsw columns are obtained using the system getrusage()
call, or the equivalent.
Since this table contains counts taken at a given point in time, for best results it is necessary to query this table periodically and store the results in an intermediate table or tables. The MySQL Server's Event Scheduler can be employed to automate such monitoring. For more information, see Section 19.4, "Using the Event Scheduler".