How to clean or resize the ibtmp1 file in MySQL?

Question

The ibtmp1 once created can’t be shrink by any method without restarting mysql service.

There are two ways to handle it:

Precaution : At the time of server start you should limit the size of this file as:

 innodb_temp_data_file_path = ibtmp1:12M:autoextend:max:5G

where max 5G means this file size limits to 5GB.

Cure : If file already created you need to restart service:

SET GLOBAL innodb_fast_shutdown = 0;
Shutdown MySQL
remove ibtmp1
start MySQL.

Docs: https://dev.mysql.com/doc/refman/5.7/en/innodb-temporary-tablespace.html