Does MySQL log successful or attempted queries?

Posted by Nathan Long on Server Fault See other posts from Server Fault or by Nathan Long
Published on 2010-04-20T22:05:28Z Indexed on 2010/04/20 22:13 UTC
Read the original article Hit count: 331

Filed under:

mysql

|

logging

I'm trying to track down a hit-or-miss bug in a web application. Sometimes a request completes just fine; sometimes it hangs and never finishes.

I see that Apache now has several requests listed on the server-status page as "sending reply," and that doesn't change. I'm testing on localhost, so there shouldn't ever be more than one.

Out of curiosity, I set MySQL to log all queries and I'm tail -fing the log file.

When things go OK, I see a pattern like this:

20 Connect root@localhost on dbname
20 Query (some query #1)
20 Query (some query #2)
(etc)
20 Quit
21 Connect (etc)

When it hangs, I see a pattern like this:

22 Connect root@localhost on dbname
22 Query (some query #1)
//nothing happens, so I try the post again
23 Connect root@localhost on dbname
23 Query (some query #1)
//nothing happens; try again
24 Connect (etc)

Here's my question: is MySQL logging attempted queries, or successful queries? In other words, if the last line I see is query #1, does that imply that query #1 or query #2 is hanging?

My guess is that the one I don't see is the problem, because the last one I see looks fine, but maybe the one I don't see is too screwed-up for MySQL to process. Thoughts?

© Server Fault or respective owner

Related posts about mysql

How to remove MySQL completely with config and library files on ubuntu 12.04 gnome 3.0

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I tried everything till now: sudo apt-get remove mysql-server mysql-client mysql-common sudo apt-get purge mysql-server mysql-client mysql-common sudo apt-get autoremove and even more commands... But whenever I am trying to locate mysql. I get a no. of files related to mysql command: shell>>… >>> More
mysql: Cannot load from mysql.proc. The table is probably corrupted

as seen on Server Fault - Search for 'Server Fault'
Mysql was started: /usr/bin/mysqld_safe --datadir=/srv/mysql/myDB --log-error=/srv/mysql/logs/mysqld-myDB.log --pid-file=/srv/mysql/pids/mysqld-myDB.pid --user=mysql --socket=/srv/mysql/sockets/mysql-myDB.sock --port=3700 but when I'm trying to do something: ERROR 1548 (HY000) at line 1: Cannot… >>> More
Why is there a /etc/init.d/mysql file on this Slackware machine? How could it have gotten there?

as seen on Server Fault - Search for 'Server Fault'
A client of my IT-consulting service owns a web-development shop. He's been having problems with a Slackware 12.0 server running MySQL 5.0.67. The machine was set up by the client's sysadmin, who left on bad terms. My client no longer employs a sysadmin. As far as I can tell, the only copy of MySQL… >>> More
mysql: Bind on unix socket: Permission denied

as seen on Server Fault - Search for 'Server Fault'
Can't start mysql with: sudo /usr/bin/mysqld_safe --datadir=/srv/mysql/myDB --log-error=/srv/mysql/logs/mysqld-myDB.log --pid-file=/srv/mysql/pids/mysqld-myDB.pid --user=mysql --socket=/srv/mysql/sockets/mysql-myDB.sock --port=3700 120222 13:40:48 mysqld_safe Starting mysqld daemon with databases… >>> More
MySQL – Learning MySQL Online in 6 Hours – MySQL Fundamentals in 320 Minutes

as seen on SQL Authority - Search for 'SQL Authority'
MySQL is one of the most popular database language and I have been recently working with it a lot. Data have no barrier and every database have their own place. I have been working with MySQL for quite a while and just like SQL Server, I often find lots of people asking me if I have a tutorial which… >>> More

Related posts about logging

log file is not getting created using JDK logging with Commons-logging

as seen on Stack Overflow - Search for 'Stack Overflow'
When I run the TestJcLLoggingService class log messages are coming to Console but no log file is created, please help me if you know the answer. two source files are pasted below. TestJcLLoggingService.java package com.amadeus.psp.pasd.logging; import org.apache.commons.logging.Log; import org… >>> More
Python logging before you run logging.basicConfig?

as seen on Stack Overflow - Search for 'Stack Overflow'
It appears that if you invoke logging.info() BEFORE you run logging.basicConfig, the logging.basicConfig call doesn't have any effect. In fact, no logging occurs. Where is this behavior documented? I don't really understand. >>> More
Python: combine logging and wx so that logging stream is redirectet to stdout/stderr frame

as seen on Stack Overflow - Search for 'Stack Overflow'
Here's the thing: I'm trying to combine the logging module with wx.App()'s redirect feature. My intention is to log to a file AND to stderr. But I want stderr/stdout redirected to a separate frame as is the feature of wx.App. My test code: import logging import wx class MyFrame(wx.Frame): … >>> More
Redirect logging output using custom logging handler

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi Guys, I'm using a module in my python app that writes a lot a of messages using the logging module. Initially I was using this in a console application and it was pretty easy to get the logging output to display on the console using a console handler. Now I've developed a GUI version of my app… >>> More
Java Logger API

as seen on Oracle Blogs - Search for 'Oracle Blogs'
This is a more like a tip rather than technical write up and serves as a quick intro for newbies. The logger API helps to diagnose application level or JDK level issues at runtime. There are 7 levels which decide the detailing in logging (SEVERE, WARNING, INFO, CONFIG, FINE, FINER, FINEST)… >>> More