The query execution probe is triggered when the actual execution of the query starts, after the parsing and checking the query cache but before any privilege checks or optimization. By comparing the difference between the start and done probes you can monitor the time actually spent servicing the query (instead of just handling the parsing and other elements of the query).
query-exec-start(query, connectionid, database, user, host, exec_type) query-exec-done(status)
The information provided in the arguments for
query-start
and
query-exec-start
are almost identical and
designed so that you can choose to monitor either the entire
query process (using query-start
) or only
the execution (using query-exec-start
)
while exposing the core information about the user, client,
and query being executed.
query-exec-start
— is triggered
when the execution of a individual query is started. The
arguments are:
query
— the full text of the
submitted query.
connectionid
— the connection
ID of the client that submitted the query. The
connection ID equals the connection ID returned when the
client first connects and the Id
value in the output from SHOW
PROCESSLIST
.
database
— the database name on
which the query is being executed.
user
— the username used to
connect to the server.
host
— the hostname of the
client.
exec_type
— the type of
execution. Execution types are determined based on the
contents of the query and where it was submitted. The
values for each type are shown in the following table.
Value | Description |
---|---|
0 | Executed query from sql_parse, top-level query. |
1 | Executed prepared statement |
2 | Executed cursor statement |
3 | Executed query in stored procedure |
query-exec-done
— is triggered when
the execution of the query has completed. The probe includes
a single argument, status
, which returns
0 when the query is successfully executed and 1 if there was
an error.
User Comments
Add your own comment.