query_cache_size_MB overflow

[llchan]

I was seeing unexpected purges when setting mysql-query_cache_size_MB=4096. After poking around the source code, I think this is due to int overflow here:

proxysql/lib/Query_Cache.cpp

Line 406 in 00f26d5

max_memory_size=mysql_thread___query_cache_size_MB*1024*1024;

because mysql_thread___query_cache_size_MB is an int. We should probably replace all the size-related vars with size_t, or at the very least cast before performing arithmetic on it.

[renecannao]

Thank you for the report.
And thank you for looking in the code before opening an issue!
max_memory_size is uint64_t , therefore the easier way to fix this is a cast.

max_memory_size = (uint64_t) mysql_thread___query_cache_size_MB*1024*1024; 

[renecannao]

Fixed in 2.0.4

[renecannao]

Closing.
Thank you again for the report!