Bug #109633: Display DB (Schema) name the thread is using in the logs during a crash

[mhagstrand]

Bug Reference: https://bugs.mysql.com/bug.php?id=109633

If a thread in MySQL causes a segfault, the signal handler will output information about that thread including the query it was executing but not the DB it is using. Below is an example of this message:

Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (7fd94c421e50): select city,state,sleep(10) from offices
Connection ID (thread ID): 13
Status: NOT_KILLED

This information does not contain the DB name the thread was using. If the MySQL instance has many DBs with identical table names it can be difficult to determine on which DB the query was executing. As a result identifying a corrupted table or index can not be done easily.

Testing:

Ran a slow query with a sleep in it:
select city,state,sleep(10) from offices;

Found the OS thread ID in performance_schema.threads

Next sent a SIGSEGV to the thread with kill

Then captured the output in the error log.

/lib/x86_64-linux-gnu/libpthread.so.0(+0x7fa3) [0x7fd9c619bfa3]
/lib/x86_64-linux-gnu/libc.so.6(clone+0x3f) [0x7fd9c596d06f]

Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (7fd94c421e50): select city,state,sleep(10) from offices
DB (7fd94c324ce0): classicmodels
Connection ID (thread ID): 13
Status: NOT_KILLED

[mysql-oca-bot]

Hi, thank you for your contribution. Please confirm this code is submitted under the terms of the OCA (Oracle's Contribution Agreement) you have previously signed by cutting and pasting the following text as a comment:
"I confirm the code being submitted is offered under the terms of the OCA, and that I am authorized to contribute it."
Thanks

[mhagstrand]

I confirm the code being submitted is offered under the terms of the OCA, and that I am authorized to contribute it.

[mysql-oca-bot]

Hi, thank you for your contribution. Your code has been assigned to an internal queue. Please follow
bug http://bugs.mysql.com/bug.php?id=109633 for updates.
Thanks