MySQL connection fast through mysql cli, but slow using PDO

Question

I have a MySQL database running on Google Cloud. It has SSL enforced, and so I use certificates and keys to connect to it:

• On the command line, I use: mysql --ssl-ca=/path/to/server-ca.pem --ssl-cert=/path/to/client-cert.pem --ssl-key=/path/to/client-key.pem --host=ip-address --user=username --password
• With PDO, I use the PDO::MYSQL_ATTR_SSL_CA , PDO::MYSQL_ATTR_SSL_CERT and PDO::MYSQL_ATTR_SSL_KEY options to indicate the required files.

Both connections work fine, except that the PDO connection in PHP is very slow. The CLI method takes milliseconds to connect and execute a queries, while the PDO method takes 5-10 times longer for the same amount of connections. I tried both methods from the same machine, so it doesn't seem to be a hardware/network issue. Could PDO be causing issues here?

I'm using Laravel in case that might be relevant.

Update: things I've tried

• Run any other PHP script (that doesn't include a MySQL connection) on the same server: perfectly fast.
• Run a PHP script that connects to a database on 127.0.0.1 / localhost and performs a query: perfectly fast.
• Connect and query using MySQL CLI (as already mentioned in the question): perfectly fast - although hard to verify how fast so I could be imagining it.
• Connect and query though PHP/PDO from different machines using all the same settings: very slow, just like the original machine I tried it on.

So the only thing I haven't tried yet is turning off SSL/TLS. Unfortunately, I cannot do that with this instance for security reasons. Also, based on the fact that a SSL/TLS connection using the CLI is very fast, I'm concluding that it must be related to something PHP- or PDO-specific.

I'm going to do some debugging myself and will add any relevant results once I have them.

Answer 1

I ended up opting for a Google Cloud Compute VM to host my PHP and then connect through a private IP. It appears that this is working.

I'm not sure if PDO was actually slower than the MySQL CLI anymore, it may have just seemed so.