Mysql – Unable to connect to cloud sql from a gcp vm instance

Check my.conf and what bindings MySql server has.

It may be so, that it listens only on the local network.

You are looking for bind-address setting in /etc/my.conf or /etc/mysql/my.conf.

If this setting is enabled (usually to bind to only localhost 127.0.0.1), comment it out, and it will allow MySql to listen on all available interfaces.

In any case, accessing the database server directly over Internet is not a good idea at all.

I would strongly advice you to use ssh tunneling to access the machine over Internet.

On windows, you can use putty to ssh (creating a tunnel) into the MySql machine. You can forward your local 3306 port to the remote one, and then you can access the MySql server using localhost:3306.

You've got a rather strange database here - it's doing a lot more writes than reads.

It's really important that you tune your DBMS to run well with Innodb or you tune it to run well with MyISAM - but you seem to have a mixture of both table types. You cannot have a DBMS which is optimal with both. You need to start migrating your data onto a single engine. Given the write heavy nature of the database, I'd recommend Innodb.

Total buffers: 480.0M global + 33.5M per thread (110 max threads)

Currently the risk of running into swap is primarily driven by the per-connection memory usage. but note that this is only a risk just now. You also need to establish whether you need 110 concurrent connections - and preferably reduce that a bit. Usually the sort_buffer_size is the main culprit for using up memory per connection - but yours is a quarter of the default.

If you are consolidating on innodb then you need should probably increase the innodb buffer pool size.

You can play around with different values here.