Re: signal handling in mysql cli

[shawn l.green]

Hello Sebastien,

You should stop top-posting, it inverts the flow of your investigation 
making it harder to follow. (see bottom)


On 6/21/2016 12:45 PM, Sebastien FLAESCH wrote:

The process list show my (killed) thread as follows:

mysql> show processlist;
++-+-+---+-+--+--+--+

| Id | User| Host| db| Command | Time | State|
Info |
++-+-+---+-+--+--+--+

| 20 | root| localhost:48203 | test1 | Query   |0 | starting |
show processlist |
| 21 | mysuser | localhost:48209 | test1 | Sleep   |  182 |  |
NULL |
++-+-+---+-+--+--+--+


Why it is in "Sleep" state?!?

Seb

On 06/21/2016 06:27 PM, Sebastien FLAESCH wrote:

FYI, I get the same problem with MySQL 5.7.13.

Seb

On 06/21/2016 04:59 PM, Sebastien FLAESCH wrote:

Seems that after KILL QUERY mysql-thread-id, a call to
mysql_stmt_close(stmt-handle) hangs...

This did not happen in 5.6 ...

Will try 5.7.13 ...

Seb

On 06/21/2016 04:03 PM, Sebastien FLAESCH wrote:

Hi all,

The technique described in this thread is working fine with MySQL
5.6 (libmysqlclient).

Basically, in a SIGINT signal handler, we establish a new connection
to perform a

KILL QUERY pid

...

But with 5.7 (5.7.11) we get now a different result:

A) The query is still interrupted, but we no longer get an SQL error
-1317.

B) For some reason, the program does not want to exit() - (must
investigate)

Any clues?


With mysql it's working fine:

mysql> select sleep(10);
^C^C -- query aborted
+---+
| sleep(10) |
+---+
+---+
1 row in set (2.79 sec)

mysql> \q
Bye



Thanks!
Seb

On 12/03/2014 05:25 PM, Sebastien FLAESCH wrote:

Hi all,

I have a similar question regarding KILL QUERY usage:

We have a C client program using libmysqlclient.so, it is a
single-threaded program.

When running a long query, how can I send the KILL QUERY command
when a SIGINT (CTRL-C)
is caught? (of course we implement a signal handler, so we keep the
control)

=> Is is safe to establish a new connection to the server in the
signal handler, using
mysql_init() + mysql_real_connect(), and execute the KILL QUERY
with the mysql thread
id I got from the initial mysql_init() / mysql_real_connect()?

I made some tests, and it seems to work fine, the long query
returns SQL error -1317:
"Query execution was interrupted" (which is expected)

We want to support SQL interruption properly, so please someone
from the dev team,
give me a clear answer... I don't want to use a side effect or
undocumented feature.

Doing all this stuff in a signal handler is certainly risky... no?

I could not find the information in the documentation
(mysql_real_connect).

I wish there would be an API like mysql_cancel_query(), similar to
Oracle's OCI
OCIBreak().

Thanks!
Seb



On 12/02/2014 05:13 PM, walter harms wrote:

hi list,

when i use CTRL-C to break a query that works fine in interactive
mode.

mysql> select sleep(10) ;
^CCtrl-C -- sending "KILL QUERY 24289" to server ...
Ctrl-C -- query aborted.
+---+
| sleep(10) |
+---+
+---+
1 row in set (0.86 sec)

but when i use the noninteractive mode
   timeout 5 mysql -BAN -e "select now(); select sleep (100) ;
select now() "

i looks like that  but "show full processlist;" shows otherwise
and that is true
as a list of long running querys showed.

Is there a way to make it behave like the interactive version ?
Now it is a bit confusing for everyone.

re,
  wh

















You did not KILL the entire client session(CONNECTION), you only killed 
the QUERY that the session was executing. The client remains connected 
and the session remains active. The reason it is in Sleep state is 
because the server is waiting for the client to send its next command.


http://dev.mysql.com/doc/refman/5.7/en/kill.html

--
Shawn Green
MySQL Senior Principal Technical Support Engineer
Oracle USA, Inc. - Integrated Cloud Applications & Platform Services
Office: Blountville, TN

Become certified in MySQL! Visit https://www.mysql.com/certification/ 
for details.


--
MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
To unsubscribe:http://lists.mysql.com/mysql

[ANN] Mroonga 6.06 - storage engine, fast fulltext search, CJK ready

[Masafumi Yokoyama]

Hi,

Mroonga 6.06 has been released!

## What is Mroonga?

Mroonga is a MySQL storage engine that supports fast fulltext search
and geolocation search.  It is CJK ready. It uses Groonga as a storage
and fulltext search engine.

Document:
   http://mroonga.org/docs/

The characteristics of Mroonga:
http://mroonga.org/docs/characteristic.html

How to install: Install Guide
   http://mroonga.org/docs/install.html

Tutorial:
   http://mroonga.org/docs/tutorial.html

## Topics

There are two topics in the recent release.

  * Supported multibyte column name in inplace ALTER TABLE for storage mode
  * Supported ORDER BY LIMIT optimization for multibyte column for
storage mode

### Improved multibyte column name related stuffs in storage mode

In this release, multibyte column name related stuffs are improved.

First, INPLACE ATER TABLE are supported for multibyte column in storage
mode.

Note that MySQL 5.6 or later can use INPLACE ALTER TABLE for adding
columns and indexes.

Second, ORDER BY LIMIT optimization for multibyte column in storage
mode is also supported.

Since Mroonga 6.02, multibyte column name was supported, above
improvements are requested from Mroonga user. Thanks!

--
Masafumi Yokoyama 
ClearCode Inc.

-- 
MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
To unsubscribe:http://lists.mysql.com/mysql