MySQL-QA-Episode-3-Notes

MySQL-QA-Episode-3-Notes

From link -> https://www.percona.com/blog/2015/07/07/mysql-qa-episode-3-how-to-use-the-debugging-tool-gdb/

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1. GDB settings:

vim ~/.gdbinit

set trace-commands on
set pagination off
set print array on
set print array-indexes on
set pretty on
set print elements 1500


2. GDB options:

* bt                   -> getting back trace.
* thread 1             -> to get in thread one.
* thread apply all bt  -> getting all threads.


Note > You must read bt output from bottom to top


3. to get in specific frame:
frame 8 

4. To list a code in specific frame:
list ( if you want to get a next(proceed) page of code push enter)


Note >:  
thread > (trace) > frames > variables (passed)

5. To check for specific variable:
p variable_name

p * (THD*) 0x4566666666666687

6. To enable logging of output:

set log on

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c++filt usage:

cat master.err | c++filt > out.txt