DEBUG syntax

DEBUG [ subcommand ]

DEBUG statement is designed to call different internal or vip commands for dev/testing purposes. It is not intended for production automation, since the syntax of subcommand part may be freely changed in any build.

Call DEBUG without params to show list of useful commands (in general) and subcommands (of DEBUG statement) available at the moment.

However you can invoke DEBUG without params to know which subcommands of the statement are available in any particular case:

mysql> debug;
+----------------+---------------------+
| command        | meaning             |
+----------------+---------------------+
| flush logs     | emulate USR1 signal |
| reload indexes | emulate HUP signal  |
+----------------+---------------------+
2 rows in set (0,00 sec)

(these commands are already documented, but such short help just remind about them).

If you connect via ‘VIP’ connection (see listen for details) the output might be a bit different:

mysql> debug;
+---------------------------+------------------------------+
| command                   | meaning                      |
+---------------------------+------------------------------+
| debug shutdown <password> | emulate TERM signal          |
| debug token <password>    | calculate token for password |
| flush logs                | emulate USR1 signal          |
| reload indexes            | emulate HUP signal           |
+---------------------------+------------------------------+
4 rows in set (0,00 sec)

Here you can see additional commands available only in the current context (namely, if you connected on a VIP port). Two additional subcommands available right now are token and shutdown. The first one just calculates a hash (SHA1) of the <password> (which, in turn, may be empty, or a word, or num/phrase enclosed in ‘-quotes) like:

mysql> debug token hello;
+-------------+------------------------------------------+
| command     | result                                   |
+-------------+------------------------------------------+
| debug token | aaf4c61ddcc5e8a2dabede0f3b482cd9aea9434d |
+-------------+------------------------------------------+
1 row in set (0,00 sec)

Another debug subcommand shutdown will send a TERM signal to the daemon and so will make it shut down. Since it is quite dangerous (nobody wants accidentally stop a production service), it 1) needs a VIP connection, and 2) needs the password. For the chosen password you need to generate a token with debug token subcommand, and put it into ref:shutdown_token param of searchd section of the config file. If no such section exists, or if a hash of the provided password does not match with the token stored in the config, the subcommand will do nothing. Otherwise it will cause ‘clean’ shutdown of the daemon.