Setting Up MySQL Debugging Environment
Table of Contents
It is strongly recommened to refer to the mysql documentation for debugging and compiling mysql sources. After configuring the debugging environment, I write this post to make further environment setting easier with just few scirpts running for others who are trying to understanding the internals of MySQL.
In the following setting, I assume you are working on a linux machine, and you are carrying on with the process of "modifying-recompiling-testing" the functions of mysql. So I suggest installing the mysql binaries into a tempory directory, /dev/shm, which is backed by DRAM, you will get good performance.
1 Get the source files from mysql.
I will leave out the details of this step, follow the guidelines from the mysql website.
2 Compile & Install with cmake/make.
The latest mysql uses cmake to configure the features of mysql and uses make to compile and install. Using the following scirpts to automate the configuring and installation.
In the topmost directory of mysql source tree, issue the following commands:
| mkdir bld |
| cd bld |
| #this makes the bld directory hold the output files |
| cmake .. -DCMAKE_BUILD_TYPE=Debug |
| make -j16 |
| rm -rf /dev/shm/usr |
| #install to the shm directory |
| make install DESTDIR="/dev/shm" |
| #Install the system tables |
| /dev/shm/usr/local/mysql/scripts/mysql_install_db –basedir=/dev/shm/usr/local/mysql –datadir=/dev/shm/usr/local/mysql/data |
Alternatively, you can copy the contents of the above commands into a shell, and execute that script each time you modify the source files.
3 Start mysqld, the server.
We use gdb to start the mysqld process so that we can debug the code.
| gdb –args /run/shm/usr/local/mysql/bin/mysqld –basedir=/run/shm/usr/local/mysql –datadir=/run/shm/usr/local/mysql/data –skip-networking |
Add a breakpoint:
Issue run command in gdb window, to start the server process.
The message in red box shows the client can connect to the server with the socket.
4 Start another termial window, and start a client.
| /dev/shm/usr/local/mysql/bin/mysql -S /tmp/mysql.sock |
Now the server is stopped at the breakpoint.
