https://blogs.oracle.com/wim/entry/mysql_5_6_20_4?utm_source=tuicool&utm_medium=referral
By WimCoekaerts-Oracle on Jul 31, 2014
The MySQL team just released MySQL 5.6.20. One of the cool new things for Oracle Linux users is the addition of MySQL DTrace probes. When you use Oracle Linux 6, or 7 with UEKr3 (3.8.x) and the latest DTrace utils/tools, then you can make use of this. MySQL 5.6 is available for install through ULN or from public-yum. You can just install it using yum.
# yum install mysql-community-server
Then install dtrace utils from ULN.
# yum install dtrace-utils
As root, enable DTrace and allow normal users to record trace information:
# modprobe fasttrap # chmod 666 /dev/dtrace/helper
Start MySQL server.
# /etc/init.d/mysqld start
Now you can try out various dtrace scripts. You can find the reference manual for MySQL DTrace support here.
Example1
Save the script below as query.d.
#!/usr/sbin/dtrace -qws
#pragma D option strsize=1024
mysql*:::query-start /* using the mysql provider */
{
self->query = copyinstr(arg0); /* Get the query */
self->connid = arg1; /* Get the connection ID */
self->db = copyinstr(arg2); /* Get the DB name */
self->who = strjoin(copyinstr(arg3),strjoin("@",
copyinstr(arg4))); /* Get the username */
printf("%Y\t %20s\t Connection ID: %d \t Database: %s \t Query: %s\n",
walltimestamp, self->who ,self->connid, self->db, self->query);
}
Run it, in another terminal, connect to MySQL server and run a few queries.
# dtrace -s query.d
dtrace: script ‘query.d‘ matched 22 probes
CPU ID FUNCTION:NAME
0 4133 _Z16dispatch_command19enum_server_commandP3THDPcj:query-start 2014
Jul 29 12:32:21 [email protected] Connection ID: 5 Database:
Query: select @@version_comment limit 1
0 4133 _Z16dispatch_command19enum_server_commandP3THDPcj:query-start 2014
Jul 29 12:32:28 [email protected] Connection ID: 5 Database:
Query: SELECT DATABASE()
0 4133 _Z16dispatch_command19enum_server_commandP3THDPcj:query-start 2014
Jul 29 12:32:28 [email protected] Connection ID: 5 Database: database
Query: show databases
0 4133 _Z16dispatch_command19enum_server_commandP3THDPcj:query-start 2014
Jul 29 12:32:28 [email protected] Connection ID: 5 Database: database
Query: show tables
0 4133 _Z16dispatch_command19enum_server_commandP3THDPcj:query-start 2014
Jul 29 12:32:31 [email protected] Connection ID: 5 Database: database
Query: select * from foo
Example 2
Save the script below as statement.d.
#!/usr/sbin/dtrace -s
#pragma D option quiet
dtrace:::BEGIN
{
printf("%-60s %-8s %-8s %-8s\n", "Query", "RowsU", "RowsM", "Dur (ms)");
}
mysql*:::update-start, mysql*:::insert-start,
mysql*:::delete-start, mysql*:::multi-delete-start,
mysql*:::multi-delete-done, mysql*:::select-start,
mysql*:::insert-select-start, mysql*:::multi-update-start
{
self->query = copyinstr(arg0);
self->querystart = timestamp;
}
mysql*:::insert-done, mysql*:::select-done,
mysql*:::delete-done, mysql*:::multi-delete-done, mysql*:::insert-select-done
/ self->querystart /
{
this->elapsed = ((timestamp - self->querystart)/1000000);
printf("%-60s %-8d %-8d %d\n",
self->query,
0,
arg1,
this->elapsed);
self->querystart = 0;
}
mysql*:::update-done, mysql*:::multi-update-done
/ self->querystart /
{
this->elapsed = ((timestamp - self->querystart)/1000000);
printf("%-60s %-8d %-8d %d\n",
self->query,
arg1,
arg2,
this->elapsed);
self->querystart = 0;
}
Run it and do a few queries.
# dtrace -s statement.d Query RowsU RowsM Dur (ms) select @@version_comment limit 1 0 1 0 SELECT DATABASE() 0 1 0 show databases 0 6 0 show tables 0 2 0 select * from foo 0 1 0